From 4d0313be19f7eace43d75b322b52f874fc5d0593 Mon Sep 17 00:00:00 2001
From: Jiuqing Song <jisong@microsoft.com>
Date: Thu, 24 Oct 2024 13:01:05 -0700
Subject: [PATCH 1/7] Merge text segments

---
 .../lib/modelApi/common/normalizeParagraph.ts | 61 ++++++++++++++++++-
 1 file changed, 58 insertions(+), 3 deletions(-)

diff --git a/packages/roosterjs-content-model-dom/lib/modelApi/common/normalizeParagraph.ts b/packages/roosterjs-content-model-dom/lib/modelApi/common/normalizeParagraph.ts
index c86efc34dae..6a760889ac2 100644
--- a/packages/roosterjs-content-model-dom/lib/modelApi/common/normalizeParagraph.ts
+++ b/packages/roosterjs-content-model-dom/lib/modelApi/common/normalizeParagraph.ts
@@ -2,12 +2,16 @@ import { areSameFormats } from '../../domToModel/utils/areSameFormats';
 import { createBr } from '../creators/createBr';
 import { isSegmentEmpty } from './isEmpty';
 import { isWhiteSpacePreserved } from '../../domUtils/isWhiteSpacePreserved';
-import { mutateBlock, mutateSegment } from './mutate';
+import { mutateBlock, mutateSegment, mutateSegments } from './mutate';
 import { normalizeAllSegments } from './normalizeSegment';
 import type {
     ContentModelSegmentFormat,
+    ContentModelText,
+    ReadonlyContentModelCode,
+    ReadonlyContentModelLink,
     ReadonlyContentModelParagraph,
     ReadonlyContentModelSegment,
+    ReadonlyContentModelText,
 } from 'roosterjs-content-model-types';
 
 /**
@@ -47,9 +51,8 @@ export function normalizeParagraph(paragraph: ReadonlyContentModelParagraph) {
     }
 
     removeEmptyLinks(paragraph);
-
     removeEmptySegments(paragraph);
-
+    mergeTextSegments(paragraph);
     moveUpSegmentFormat(paragraph);
 }
 
@@ -73,6 +76,58 @@ function removeEmptySegments(block: ReadonlyContentModelParagraph) {
     }
 }
 
+function mergeTextSegments(block: ReadonlyContentModelParagraph) {
+    let lastText: ReadonlyContentModelText | null = null;
+
+    for (let i = 0; i < block.segments.length; i++) {
+        const segment = block.segments[i];
+
+        if (segment.segmentType != 'Text') {
+            lastText = null;
+        } else if (!lastText || !segmentsWithSameFormat(lastText, segment)) {
+            lastText = segment;
+        } else {
+            const [mutableBlock, [mutableLastText]] = mutateSegments(block, [lastText, segment]);
+
+            (mutableLastText as ContentModelText).text += segment.text;
+            mutableBlock.segments.splice(i, 1);
+            i--;
+        }
+    }
+}
+
+function segmentsWithSameFormat(
+    seg1: ReadonlyContentModelSegment,
+    seg2: ReadonlyContentModelSegment
+) {
+    return (
+        !!seg1.isSelected == !!seg2.isSelected &&
+        areSameFormats(seg1.format, seg2.format) &&
+        areSameLinks(seg1.link, seg2.link) &&
+        areSameCodes(seg1.code, seg2.code)
+    );
+}
+
+function areSameLinks(
+    link1: ReadonlyContentModelLink | undefined,
+    link2: ReadonlyContentModelLink | undefined
+) {
+    return (
+        (!link1 && !link2) ||
+        (link1 &&
+            link2 &&
+            areSameFormats(link1.format, link2.format) &&
+            areSameFormats(link1.dataset, link2.dataset))
+    );
+}
+
+function areSameCodes(
+    code1: ReadonlyContentModelCode | undefined,
+    code2: ReadonlyContentModelCode | undefined
+) {
+    return (!code1 && !code2) || (code1 && code2 && areSameFormats(code1.format, code2.format));
+}
+
 function removeEmptyLinks(paragraph: ReadonlyContentModelParagraph) {
     const marker = paragraph.segments.find(x => x.segmentType == 'SelectionMarker');
     if (marker) {

From 977181444ac58fdf9f0211b2b2bcc682d7095601 Mon Sep 17 00:00:00 2001
From: Jiuqing Song <jisong@microsoft.com>
Date: Thu, 24 Oct 2024 14:00:02 -0700
Subject: [PATCH 2/7] Fix test

---
 .../command/paste/mergePasteContentTest.ts    |  54 +---
 .../common/normalizeContentModelTest.ts       |   7 +-
 .../modelApi/common/normalizeParagraphTest.ts |  21 +-
 .../test/modelApi/editing/mergeModelTest.ts   |  25 +-
 .../paste/processPastedContentFromWacTest.ts  | 290 ++----------------
 ...processPastedContentFromWordDesktopTest.ts |  28 +-
 6 files changed, 42 insertions(+), 383 deletions(-)

diff --git a/packages/roosterjs-content-model-core/test/command/paste/mergePasteContentTest.ts b/packages/roosterjs-content-model-core/test/command/paste/mergePasteContentTest.ts
index 71efb5798c0..2810be3d786 100644
--- a/packages/roosterjs-content-model-core/test/command/paste/mergePasteContentTest.ts
+++ b/packages/roosterjs-content-model-core/test/command/paste/mergePasteContentTest.ts
@@ -971,7 +971,7 @@ describe('mergePasteContent', () => {
                         segments: [
                             {
                                 segmentType: 'Text',
-                                text: 'Unformatted line',
+                                text: 'Unformatted line\n',
                                 format: {
                                     fontSize: '14px',
                                     textColor: 'white',
@@ -1149,15 +1149,7 @@ describe('mergePasteContent', () => {
                     segments: [
                         {
                             segmentType: 'Text',
-                            text: 'Unformatted line',
-                            format: {
-                                fontSize: '14px',
-                                textColor: 'white',
-                            },
-                        },
-                        {
-                            segmentType: 'Text',
-                            text: '\n',
+                            text: 'Unformatted line\n',
                             format: {
                                 fontSize: '14px',
                                 textColor: 'white',
@@ -1490,15 +1482,7 @@ describe('mergePasteContent', () => {
                         segments: [
                             {
                                 segmentType: 'Text',
-                                text: 'Inline text',
-                                format: {
-                                    fontSize: '14px',
-                                    textColor: 'rgb(0,0,0)',
-                                },
-                            },
-                            {
-                                segmentType: 'Text',
-                                text: '\n',
+                                text: 'Inline text\n',
                                 format: {
                                     fontSize: '14px',
                                     textColor: 'rgb(0,0,0)',
@@ -1553,15 +1537,7 @@ describe('mergePasteContent', () => {
                         },
                         {
                             segmentType: 'Text',
-                            text: 'Inline text',
-                            format: {
-                                fontSize: '14px',
-                                textColor: 'rgb(0,0,0)',
-                            },
-                        },
-                        {
-                            segmentType: 'Text',
-                            text: '\n',
+                            text: 'Inline text\n',
                             format: {
                                 fontSize: '14px',
                                 textColor: 'rgb(0,0,0)',
@@ -1629,16 +1605,7 @@ describe('mergePasteContent', () => {
                         segments: [
                             {
                                 segmentType: 'Text',
-                                text: 'Inline text',
-                                format: {
-                                    fontFamily: 'Aptos',
-                                    fontSize: '14px',
-                                    textColor: 'white',
-                                },
-                            },
-                            {
-                                segmentType: 'Text',
-                                text: '\n',
+                                text: 'Inline text\n',
                                 format: {
                                     fontFamily: 'Aptos',
                                     fontSize: '14px',
@@ -1686,16 +1653,7 @@ describe('mergePasteContent', () => {
                         { segmentType: 'Text', text: 'Text in source', format: {} },
                         {
                             segmentType: 'Text',
-                            text: 'Inline text',
-                            format: {
-                                fontFamily: 'Aptos',
-                                fontSize: '14px',
-                                textColor: 'white',
-                            },
-                        },
-                        {
-                            segmentType: 'Text',
-                            text: '\n',
+                            text: 'Inline text\n',
                             format: {
                                 fontFamily: 'Aptos',
                                 fontSize: '14px',
diff --git a/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeContentModelTest.ts b/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeContentModelTest.ts
index bc3aa260c52..3466a7656b3 100644
--- a/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeContentModelTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeContentModelTest.ts
@@ -59,12 +59,7 @@ describe('normalizeContentModel', () => {
                         {
                             segmentType: 'Text',
                             format: {},
-                            text: 'test1',
-                        },
-                        {
-                            segmentType: 'Text',
-                            format: {},
-                            text: 'test2',
+                            text: 'test1test2',
                         },
                     ],
                 },
diff --git a/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts b/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts
index 1de5d7c3e3b..dea4db38112 100644
--- a/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts
@@ -69,9 +69,9 @@ describe('Normalize text that contains space', () => {
     });
 
     it('Text ends with &nbsp;', () => {
-        runTest(['a\u00A0', 'b'], ['a ', 'b']);
-        runTest(['a\u00A0\u00A0', 'b'], ['a\u00A0 ', 'b']);
-        runTest(['a \u00A0', 'b'], ['a \u00A0', 'b']);
+        runTest(['a\u00A0', 'b'], ['a b']);
+        runTest(['a\u00A0\u00A0', 'b'], ['a\u00A0 b']);
+        runTest(['a \u00A0', 'b'], ['a \u00A0b']);
     });
 
     it('with other type of segment', () => {
@@ -166,12 +166,7 @@ describe('Normalize text that contains space', () => {
                     segments: [
                         {
                             segmentType: 'Text',
-                            text: 'a ',
-                            format: {},
-                        },
-                        {
-                            segmentType: 'Text',
-                            text: '\u00A0b',
+                            text: 'a \u00A0b',
                             format: {},
                         },
                     ],
@@ -528,17 +523,11 @@ describe('Move up format', () => {
             segments: [
                 {
                     segmentType: 'Text',
-                    text: 'test1',
-                    format: {},
-                },
-                {
-                    segmentType: 'Text',
-                    text: 'test2',
+                    text: 'test1test2',
                     format: {},
                 },
             ],
             format: {},
-            cachedElement: mockedCache,
         });
     });
 
diff --git a/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts b/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts
index 6d55c59b8d7..11e93d3d0cf 100644
--- a/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts
@@ -96,12 +96,7 @@ describe('mergeModel', () => {
             segments: [
                 {
                     segmentType: 'Text',
-                    text: 'test1',
-                    format: {},
-                },
-                {
-                    segmentType: 'Text',
-                    text: 'test2',
+                    text: 'test1test2',
                     format: {},
                 },
                 {
@@ -400,12 +395,7 @@ describe('mergeModel', () => {
                             segments: [
                                 {
                                     segmentType: 'Text',
-                                    text: 'test11',
-                                    format: {},
-                                },
-                                {
-                                    segmentType: 'Text',
-                                    text: 'newText1',
+                                    text: 'test11newText1',
                                     format: {},
                                 },
                             ],
@@ -1700,12 +1690,7 @@ describe('mergeModel', () => {
                 },
                 {
                     segmentType: 'Text',
-                    text: 'test1',
-                    format: {},
-                },
-                {
-                    segmentType: 'Text',
-                    text: 'new text',
+                    text: 'test1new text',
                     format: {},
                 },
                 marker2,
@@ -2952,9 +2937,7 @@ describe('mergeModel', () => {
         const paragraph: ContentModelParagraph = {
             blockType: 'Paragraph',
             segments: [
-                { segmentType: 'Text', text: 'test1', format: {} },
-                { segmentType: 'Text', text: 'sourceTest1', format: {} },
-                { segmentType: 'Text', text: 'sourceTest2', format: {} },
+                { segmentType: 'Text', text: 'test1sourceTest1sourceTest2', format: {} },
                 {
                     segmentType: 'SelectionMarker',
                     isSelected: true,
diff --git a/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWacTest.ts b/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWacTest.ts
index 50ff7a50e80..fab4753280f 100644
--- a/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWacTest.ts
+++ b/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWacTest.ts
@@ -3103,10 +3103,7 @@ describe('wordOnlineHandler', () => {
                 blocks: [
                     {
                         blockType: 'Paragraph',
-                        segments: [
-                            { segmentType: 'Text', text: 'it went: ', format: {} },
-                            { segmentType: 'Text', text: ' ', format: {} },
-                        ],
+                        segments: [{ segmentType: 'Text', text: 'it went:  ', format: {} }],
                         format: { marginTop: '1em', marginBottom: '1em' },
                         decorator: { tagName: 'p', format: {} },
                     },
@@ -3135,10 +3132,7 @@ describe('wordOnlineHandler', () => {
                         blocks: [
                             {
                                 blockType: 'Paragraph',
-                                segments: [
-                                    { segmentType: 'Text', text: 'Test.', format: {} },
-                                    { segmentType: 'Text', text: ' ', format: {} },
-                                ],
+                                segments: [{ segmentType: 'Text', text: 'Test. ', format: {} }],
                                 format: { marginTop: '1em', marginBottom: '1em' },
                                 decorator: { tagName: 'p', format: {} },
                             },
@@ -4417,19 +4411,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -4483,19 +4465,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -4549,19 +4519,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -4625,19 +4583,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -4701,19 +4647,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -4787,19 +4721,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -4873,19 +4795,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -4949,19 +4859,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5025,19 +4923,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5091,19 +4977,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5258,19 +5132,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            textColor: 'rgb(0, 0, 0)',
-                                            fontWeight: 'normal',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5369,19 +5231,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5441,19 +5291,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            textColor: 'rgb(0, 0, 0)',
-                                            fontWeight: 'normal',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5502,19 +5340,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5619,19 +5445,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            textColor: 'rgb(0, 0, 0)',
-                                            fontWeight: 'normal',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5730,19 +5544,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5801,19 +5603,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5918,19 +5708,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            textColor: 'rgb(0, 0, 0)',
-                                            fontWeight: 'normal',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -5979,19 +5757,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
@@ -6050,19 +5816,7 @@ describe('wordOnlineHandler', () => {
                                 segments: [
                                     {
                                         segmentType: 'Text',
-                                        text: '_',
-                                        format: {
-                                            fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
-                                            fontSize: '12pt',
-                                            italic: false,
-                                            fontWeight: 'normal',
-                                            textColor: 'rgb(0, 0, 0)',
-                                            lineHeight: '22.0875px',
-                                        },
-                                    },
-                                    {
-                                        segmentType: 'Text',
-                                        text: ' ',
+                                        text: '_ ',
                                         format: {
                                             fontFamily: 'Aptos, Aptos_MSFontService, sans-serif',
                                             fontSize: '12pt',
diff --git a/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWordDesktopTest.ts b/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWordDesktopTest.ts
index 07f17b4039d..bfa5272bc6e 100644
--- a/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWordDesktopTest.ts
+++ b/packages/roosterjs-content-model-plugins/test/paste/processPastedContentFromWordDesktopTest.ts
@@ -80,12 +80,7 @@ describe('processPastedContentFromWordDesktopTest', () => {
                     segments: [
                         {
                             segmentType: 'Text',
-                            text: 'Test',
-                            format: {},
-                        },
-                        {
-                            segmentType: 'Text',
-                            text: 'Test',
+                            text: 'TestTest',
                             format: {},
                         },
                     ],
@@ -106,12 +101,7 @@ describe('processPastedContentFromWordDesktopTest', () => {
                     segments: [
                         {
                             segmentType: 'Text',
-                            text: 'Test',
-                            format: {},
-                        },
-                        {
-                            segmentType: 'Text',
-                            text: 'Test',
+                            text: 'TestTest',
                             format: {},
                         },
                     ],
@@ -4264,12 +4254,7 @@ describe('processPastedContentFromWordDesktopTest', () => {
                                     isImplicit: true,
                                     segments: [
                                         {
-                                            text: 'text',
-                                            segmentType: 'Text',
-                                            format: {},
-                                        },
-                                        {
-                                            text: '.',
+                                            text: 'text.',
                                             segmentType: 'Text',
                                             format: {},
                                         },
@@ -4848,12 +4833,7 @@ describe('processPastedContentFromWordDesktopTest', () => {
                                     isImplicit: true,
                                     segments: [
                                         {
-                                            text: 'text',
-                                            segmentType: 'Text',
-                                            format: {},
-                                        },
-                                        {
-                                            text: ' ',
+                                            text: 'text ',
                                             segmentType: 'Text',
                                             format: {},
                                         },

From c3397c7b51c2c6f31b4c2b4b57d6d4794f26527a Mon Sep 17 00:00:00 2001
From: jiuqingsong <jisong@microsoft.com>
Date: Thu, 24 Oct 2024 17:12:55 -0700
Subject: [PATCH 3/7] merge node

---
 .../lib/corePlugin/cache/domIndexerImpl.ts    | 16 +++++
 .../lib/modelToDom/contentModelToDom.ts       |  7 ++-
 .../modelToDom/handlers/handleParagraph.ts    |  2 +-
 .../lib/modelToDom/optimizers/optimize.ts     | 59 ++++++++++++++++++-
 .../lib/context/DomIndexer.ts                 |  9 +++
 .../lib/context/ModelToDomSelectionContext.ts |  5 ++
 6 files changed, 92 insertions(+), 6 deletions(-)

diff --git a/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts b/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts
index 001b80a0fde..d9ec8246aa5 100644
--- a/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts
+++ b/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts
@@ -145,6 +145,10 @@ function getIndexedTableItem(element: HTMLTableElement): TableItem | null {
     }
 }
 
+function unindex(node: Node) {
+    delete (node as any).__roosterjsContentModel;
+}
+
 /**
  * @internal
  * Implementation of DomIndexer
@@ -197,6 +201,18 @@ export class DomIndexerImpl implements DomIndexer {
         this.onBlockEntityDelimiter(entity.wrapper.nextSibling, entity, group);
     }
 
+    onMergeText(targetText: Text, sourceText: Text) {
+        if (isIndexedSegment(targetText) && isIndexedSegment(sourceText)) {
+            targetText.__roosterjsContentModel.segments.push(
+                ...sourceText.__roosterjsContentModel.segments
+            );
+        } else {
+            unindex(targetText);
+        }
+
+        unindex(sourceText);
+    }
+
     reconcileSelection(
         model: ContentModelDocument,
         newSelection: DOMSelection,
diff --git a/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts b/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts
index 131e7d68730..503da52b654 100644
--- a/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts
+++ b/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts
@@ -36,8 +36,6 @@ export function contentModelToDom(
         (model as ContentModelDocumentWithPersistedCache).persistCache = true;
     }
 
-    root.normalize();
-
     return range;
 }
 
@@ -83,7 +81,10 @@ function calcPosition(
         if (!pos.segment) {
             result = { container: pos.block, offset: 0 };
         } else if (isNodeOfType(pos.segment, 'TEXT_NODE')) {
-            result = { container: pos.segment, offset: pos.segment.nodeValue?.length || 0 };
+            result = {
+                container: pos.segment,
+                offset: pos.offset ?? pos.segment.nodeValue?.length ?? 0,
+            };
         } else if (pos.segment.parentNode) {
             result = {
                 container: pos.segment.parentNode,
diff --git a/packages/roosterjs-content-model-dom/lib/modelToDom/handlers/handleParagraph.ts b/packages/roosterjs-content-model-dom/lib/modelToDom/handlers/handleParagraph.ts
index 2ae14c63391..73054976b03 100644
--- a/packages/roosterjs-content-model-dom/lib/modelToDom/handlers/handleParagraph.ts
+++ b/packages/roosterjs-content-model-dom/lib/modelToDom/handlers/handleParagraph.ts
@@ -98,7 +98,7 @@ export const handleParagraph: ContentModelBlockHandler<ContentModelParagraph> =
                 handleSegments();
             }
 
-            optimize(container);
+            optimize(container, context);
 
             // It is possible the next sibling node is changed during processing child segments
             // e.g. When this paragraph is an implicit paragraph and it contains an inline entity segment
diff --git a/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts b/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts
index eed720aa157..19cd4ceb2aa 100644
--- a/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts
+++ b/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts
@@ -1,11 +1,16 @@
 import { isEntityElement } from '../../domUtils/entityUtils';
+import { isNodeOfType } from '../../domUtils/isNodeOfType';
 import { mergeNode } from './mergeNode';
 import { removeUnnecessarySpan } from './removeUnnecessarySpan';
+import type {
+    ModelToDomBlockAndSegmentNode,
+    ModelToDomContext,
+} from 'roosterjs-content-model-types';
 
 /**
  * @internal
  */
-export function optimize(root: Node) {
+export function optimize(root: Node, context: ModelToDomContext) {
     /**
      * Do no do any optimization to entity
      */
@@ -17,6 +22,56 @@ export function optimize(root: Node) {
     mergeNode(root);
 
     for (let child = root.firstChild; child; child = child.nextSibling) {
-        optimize(child);
+        optimize(child, context);
+    }
+
+    normalizeTextNode(root, context);
+}
+
+// Merge continuous text nodes into one single node (same with normalize()),
+// and update selection and dom indexes
+function normalizeTextNode(root: Node, context: ModelToDomContext) {
+    let lastText: Text | null = null;
+    let child: Node | null;
+    let next: Node | null;
+    const selection = context.regularSelection;
+
+    for (
+        child = root.firstChild, next = child ? child.nextSibling : null;
+        child;
+        child = next, next = child ? child.nextSibling : null
+    ) {
+        if (!isNodeOfType(child, 'TEXT_NODE')) {
+            lastText = null;
+        } else if (!lastText) {
+            lastText = child;
+        } else {
+            const originalLength = lastText.nodeValue?.length ?? 0;
+
+            lastText.nodeValue += child.nodeValue ?? '';
+            context.domIndexer?.onMergeText(lastText, child);
+
+            if (selection) {
+                updateSelection(selection.start, lastText, child, originalLength);
+                updateSelection(selection.end, lastText, child, originalLength);
+            }
+
+            root.removeChild(child);
+        }
+    }
+}
+
+function updateSelection(
+    mark: ModelToDomBlockAndSegmentNode | undefined,
+    lastText: Text,
+    nextText: Text,
+    lastTextOriginalLength: number
+) {
+    if (mark && mark.offset == undefined) {
+        if (mark.segment == lastText) {
+            mark.offset = lastTextOriginalLength;
+        } else if (mark.segment == nextText) {
+            mark.segment = lastText;
+        }
     }
 }
diff --git a/packages/roosterjs-content-model-types/lib/context/DomIndexer.ts b/packages/roosterjs-content-model-types/lib/context/DomIndexer.ts
index 7c600dc0c8f..60a3429a919 100644
--- a/packages/roosterjs-content-model-types/lib/context/DomIndexer.ts
+++ b/packages/roosterjs-content-model-types/lib/context/DomIndexer.ts
@@ -43,6 +43,15 @@ export interface DomIndexer {
      */
     onBlockEntity: (entity: ContentModelEntity, group: ContentModelBlockGroup) => void;
 
+    /**
+     * Invoke when merge two continuous text nodes, we need to merge their indexes as well
+     * @param targetText Target text node to merge into
+     * @param sourceText Source text node to merge from
+     * @example Assume we have two text nodes: Node1="Foo", Node2="Bar", after merge,
+     * Node1 will become "FooBar", Node2 will be removed from DOM tree
+     */
+    onMergeText: (targetText: Text, sourceText: Text) => void;
+
     /**
      * When document content or selection is changed by user, we need to use this function to update the content model
      * to reflect the latest document. This process can fail since the selected node may not have a related model data structure.
diff --git a/packages/roosterjs-content-model-types/lib/context/ModelToDomSelectionContext.ts b/packages/roosterjs-content-model-types/lib/context/ModelToDomSelectionContext.ts
index d1af5f375c3..525b2aec21e 100644
--- a/packages/roosterjs-content-model-types/lib/context/ModelToDomSelectionContext.ts
+++ b/packages/roosterjs-content-model-types/lib/context/ModelToDomSelectionContext.ts
@@ -14,6 +14,11 @@ export interface ModelToDomBlockAndSegmentNode {
      * Segment node of this position. When provided, it represents the position right after this node
      */
     segment: Node | null;
+
+    /**
+     * Offset number of this position. It is only used for Text node, default value is 0
+     */
+    offset?: number;
 }
 
 /**

From 3fa9fa8de09142d6d8ac1ef3cb5b7bda08570022 Mon Sep 17 00:00:00 2001
From: Jiuqing Song <jisong@microsoft.com>
Date: Fri, 25 Oct 2024 10:19:32 -0700
Subject: [PATCH 4/7] fix build and test

---
 .../lib/modelToDom/contentModelToDom.ts                     | 2 ++
 .../test/domToModel/processors/brProcessorTest.ts           | 1 +
 .../test/domToModel/processors/entityProcessorTest.ts       | 1 +
 .../test/domToModel/processors/generalProcessorTest.ts      | 1 +
 .../test/domToModel/processors/imageProcessorTest.ts        | 1 +
 .../test/domToModel/processors/tableProcessorTest.ts        | 1 +
 .../test/domToModel/processors/textProcessorTest.ts         | 3 +++
 .../test/modelToDom/handlers/handleParagraphTest.ts         | 4 +++-
 .../test/modelToDom/handlers/handleTableTest.ts             | 1 +
 .../test/modelToDom/optimizers/optimizeTest.ts              | 6 +++---
 10 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts b/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts
index 503da52b654..cfdde4f1520 100644
--- a/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts
+++ b/packages/roosterjs-content-model-dom/lib/modelToDom/contentModelToDom.ts
@@ -36,6 +36,8 @@ export function contentModelToDom(
         (model as ContentModelDocumentWithPersistedCache).persistCache = true;
     }
 
+    root.normalize();
+
     return range;
 }
 
diff --git a/packages/roosterjs-content-model-dom/test/domToModel/processors/brProcessorTest.ts b/packages/roosterjs-content-model-dom/test/domToModel/processors/brProcessorTest.ts
index 9ba29b9601b..5d36f9b76e6 100644
--- a/packages/roosterjs-content-model-dom/test/domToModel/processors/brProcessorTest.ts
+++ b/packages/roosterjs-content-model-dom/test/domToModel/processors/brProcessorTest.ts
@@ -77,6 +77,7 @@ describe('brProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/domToModel/processors/entityProcessorTest.ts b/packages/roosterjs-content-model-dom/test/domToModel/processors/entityProcessorTest.ts
index 8521782a205..52b005ea005 100644
--- a/packages/roosterjs-content-model-dom/test/domToModel/processors/entityProcessorTest.ts
+++ b/packages/roosterjs-content-model-dom/test/domToModel/processors/entityProcessorTest.ts
@@ -262,6 +262,7 @@ describe('entityProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/domToModel/processors/generalProcessorTest.ts b/packages/roosterjs-content-model-dom/test/domToModel/processors/generalProcessorTest.ts
index a6d516f3e66..528415eb76f 100644
--- a/packages/roosterjs-content-model-dom/test/domToModel/processors/generalProcessorTest.ts
+++ b/packages/roosterjs-content-model-dom/test/domToModel/processors/generalProcessorTest.ts
@@ -397,6 +397,7 @@ describe('generalProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/domToModel/processors/imageProcessorTest.ts b/packages/roosterjs-content-model-dom/test/domToModel/processors/imageProcessorTest.ts
index 15bd59f68a7..ec391daf6a6 100644
--- a/packages/roosterjs-content-model-dom/test/domToModel/processors/imageProcessorTest.ts
+++ b/packages/roosterjs-content-model-dom/test/domToModel/processors/imageProcessorTest.ts
@@ -326,6 +326,7 @@ describe('imageProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/domToModel/processors/tableProcessorTest.ts b/packages/roosterjs-content-model-dom/test/domToModel/processors/tableProcessorTest.ts
index 27bcf4221be..c18816850d4 100644
--- a/packages/roosterjs-content-model-dom/test/domToModel/processors/tableProcessorTest.ts
+++ b/packages/roosterjs-content-model-dom/test/domToModel/processors/tableProcessorTest.ts
@@ -293,6 +293,7 @@ describe('tableProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/domToModel/processors/textProcessorTest.ts b/packages/roosterjs-content-model-dom/test/domToModel/processors/textProcessorTest.ts
index 621e29e17a8..40fb02ac06b 100644
--- a/packages/roosterjs-content-model-dom/test/domToModel/processors/textProcessorTest.ts
+++ b/packages/roosterjs-content-model-dom/test/domToModel/processors/textProcessorTest.ts
@@ -580,6 +580,7 @@ describe('textProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
@@ -617,6 +618,7 @@ describe('textProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
@@ -665,6 +667,7 @@ describe('textProcessor', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts b/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts
index 2c906304572..74a896ed06c 100644
--- a/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts
@@ -431,7 +431,7 @@ describe('handleParagraph', () => {
         expect(para2.cachedElement).toBe(parent.firstChild?.nextSibling as HTMLElement);
         expect(para2.cachedElement?.outerHTML).toBe('<div style="white-space: pre;">test2</div>');
 
-        optimize(parent);
+        optimize(parent, context);
 
         expect(parent.innerHTML).toBe(
             '<div style="white-space: pre;">test1</div><div style="white-space: pre;">test2</div><br>'
@@ -584,6 +584,7 @@ describe('handleParagraph', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
@@ -630,6 +631,7 @@ describe('handleParagraph', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleTableTest.ts b/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleTableTest.ts
index 5eac39a4727..75cc441f0c3 100644
--- a/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleTableTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleTableTest.ts
@@ -604,6 +604,7 @@ describe('handleTable', () => {
             reconcileChildList: null!,
             onBlockEntity: null!,
             reconcileElementId: null!,
+            onMergeText: null!,
         };
 
         context.domIndexer = domIndexer;
diff --git a/packages/roosterjs-content-model-dom/test/modelToDom/optimizers/optimizeTest.ts b/packages/roosterjs-content-model-dom/test/modelToDom/optimizers/optimizeTest.ts
index 3d3a934706f..c3acd36e9b4 100644
--- a/packages/roosterjs-content-model-dom/test/modelToDom/optimizers/optimizeTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelToDom/optimizers/optimizeTest.ts
@@ -11,7 +11,7 @@ describe('optimize', () => {
 
     it('Optimize', () => {
         const div = document.createElement('div');
-        optimize(div);
+        optimize(div, {} as any);
 
         expect(mergeNode.mergeNode).toHaveBeenCalled();
         expect(removeUnnecessarySpan.removeUnnecessarySpan).toHaveBeenCalled();
@@ -22,7 +22,7 @@ describe('optimize', () => {
         const span = document.createElement('span');
         div.appendChild(span);
 
-        optimize(div);
+        optimize(div, {} as any);
 
         expect(mergeNode.mergeNode).toHaveBeenCalledTimes(2);
         expect(mergeNode.mergeNode).toHaveBeenCalledWith(div);
@@ -49,7 +49,7 @@ describe('real optimization', () => {
         div.appendChild(span1);
         div.appendChild(span2);
 
-        optimize(div);
+        optimize(div, {} as any);
 
         expect(div.outerHTML).toBe(
             '<div>test1<span class="_Entity _EType_test _EReadonly_1" contenteditable="false"><span>entity</span></span></div>'

From 2c185e1d6be187c83993bed70be2b8e88183d1c8 Mon Sep 17 00:00:00 2001
From: Jiuqing Song <jisong@microsoft.com>
Date: Fri, 25 Oct 2024 12:14:24 -0700
Subject: [PATCH 5/7] add test

---
 .../lib/corePlugin/cache/domIndexerImpl.ts    | 18 ++--
 .../corePlugin/cache/domIndexerImplTest.ts    | 97 +++++++++++++++++++
 .../lib/modelToDom/optimizers/optimize.ts     |  2 +-
 3 files changed, 109 insertions(+), 8 deletions(-)

diff --git a/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts b/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts
index d9ec8246aa5..dd96fd509ae 100644
--- a/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts
+++ b/packages/roosterjs-content-model-core/lib/corePlugin/cache/domIndexerImpl.ts
@@ -145,8 +145,9 @@ function getIndexedTableItem(element: HTMLTableElement): TableItem | null {
     }
 }
 
-function unindex(node: Node) {
-    delete (node as any).__roosterjsContentModel;
+// Make a node not indexed. Do not export this function since we should not let code outside here know this detail
+function unindex(node: Partial<IndexedSegmentNode>) {
+    delete node.__roosterjsContentModel;
 }
 
 /**
@@ -203,14 +204,17 @@ export class DomIndexerImpl implements DomIndexer {
 
     onMergeText(targetText: Text, sourceText: Text) {
         if (isIndexedSegment(targetText) && isIndexedSegment(sourceText)) {
-            targetText.__roosterjsContentModel.segments.push(
-                ...sourceText.__roosterjsContentModel.segments
-            );
+            if (targetText.nextSibling == sourceText) {
+                targetText.__roosterjsContentModel.segments.push(
+                    ...sourceText.__roosterjsContentModel.segments
+                );
+
+                unindex(sourceText);
+            }
         } else {
+            unindex(sourceText);
             unindex(targetText);
         }
-
-        unindex(sourceText);
     }
 
     reconcileSelection(
diff --git a/packages/roosterjs-content-model-core/test/corePlugin/cache/domIndexerImplTest.ts b/packages/roosterjs-content-model-core/test/corePlugin/cache/domIndexerImplTest.ts
index 85c4310d0b6..a1a3b565a75 100644
--- a/packages/roosterjs-content-model-core/test/corePlugin/cache/domIndexerImplTest.ts
+++ b/packages/roosterjs-content-model-core/test/corePlugin/cache/domIndexerImplTest.ts
@@ -250,6 +250,103 @@ describe('domIndexerImpl.onBlockEntity', () => {
     });
 });
 
+describe('domIndexImpl.onMergeText', () => {
+    it('Two unindexed node', () => {
+        const text1 = document.createTextNode('test1');
+        const text2 = document.createTextNode('test1');
+        const div = document.createElement('div');
+
+        div.appendChild(text1);
+        div.appendChild(text2);
+
+        new DomIndexerImpl().onMergeText(text1, text2);
+
+        expect(((text1 as Node) as IndexedSegmentNode).__roosterjsContentModel).toBeUndefined();
+        expect(((text2 as Node) as IndexedSegmentNode).__roosterjsContentModel).toBeUndefined();
+    });
+
+    it('One indexed node, one unindexed node', () => {
+        const text1 = document.createTextNode('test1');
+        const text2 = document.createTextNode('test1');
+        const div = document.createElement('div');
+
+        div.appendChild(text1);
+        div.appendChild(text2);
+
+        ((text1 as Node) as IndexedSegmentNode).__roosterjsContentModel = {
+            paragraph: createParagraph(),
+            segments: [],
+        };
+
+        new DomIndexerImpl().onMergeText(text1, text2);
+
+        expect(((text1 as Node) as IndexedSegmentNode).__roosterjsContentModel).toBeUndefined();
+        expect(((text2 as Node) as IndexedSegmentNode).__roosterjsContentModel).toBeUndefined();
+    });
+
+    it('Two separated indexed node', () => {
+        const text1 = document.createTextNode('test1');
+        const text2 = document.createTextNode('test1');
+        const div = document.createElement('div');
+
+        div.appendChild(text1);
+        div.appendChild(document.createElement('img'));
+        div.appendChild(text2);
+
+        const text1Model = createText('test1');
+        const text2Model = createText('test2');
+
+        ((text1 as Node) as IndexedSegmentNode).__roosterjsContentModel = {
+            paragraph: createParagraph(),
+            segments: [text1Model],
+        };
+        ((text2 as Node) as IndexedSegmentNode).__roosterjsContentModel = {
+            paragraph: createParagraph(),
+            segments: [text2Model],
+        };
+
+        new DomIndexerImpl().onMergeText(text1, text2);
+
+        expect(((text1 as Node) as IndexedSegmentNode).__roosterjsContentModel).toEqual({
+            paragraph: createParagraph(),
+            segments: [text1Model],
+        });
+        expect(((text2 as Node) as IndexedSegmentNode).__roosterjsContentModel).toEqual({
+            paragraph: createParagraph(),
+            segments: [text2Model],
+        });
+    });
+
+    it('Two continuous indexed node', () => {
+        const text1 = document.createTextNode('test1');
+        const text2 = document.createTextNode('test1');
+        const div = document.createElement('div');
+
+        div.appendChild(text1);
+        div.appendChild(text2);
+
+        const text1Model = createText('test1');
+        const text2Model = createText('test2');
+
+        ((text1 as Node) as IndexedSegmentNode).__roosterjsContentModel = {
+            paragraph: createParagraph(),
+            segments: [text1Model],
+        };
+        ((text2 as Node) as IndexedSegmentNode).__roosterjsContentModel = {
+            paragraph: createParagraph(),
+            segments: [text2Model],
+        };
+
+        new DomIndexerImpl().onMergeText(text1, text2);
+
+        expect(((text1 as Node) as IndexedSegmentNode).__roosterjsContentModel).toEqual({
+            paragraph: createParagraph(),
+            segments: [text1Model, text2Model],
+        });
+        expect(((text2 as Node) as IndexedSegmentNode).__roosterjsContentModel).toBeUndefined();
+    });
+});
+
 describe('domIndexerImpl.reconcileSelection', () => {
     let setSelectionSpy: jasmine.Spy;
     let model: ContentModelDocument;
diff --git a/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts b/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts
index 19cd4ceb2aa..465017f41f4 100644
--- a/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts
+++ b/packages/roosterjs-content-model-dom/lib/modelToDom/optimizers/optimize.ts
@@ -48,8 +48,8 @@ function normalizeTextNode(root: Node, context: ModelToDomContext) {
         } else {
             const originalLength = lastText.nodeValue?.length ?? 0;
 
-            lastText.nodeValue += child.nodeValue ?? '';
             context.domIndexer?.onMergeText(lastText, child);
+            lastText.nodeValue += child.nodeValue ?? '';
 
             if (selection) {
                 updateSelection(selection.start, lastText, child, originalLength);

From a0305689dc97202bacb1f60e2b66c26e322aeee1 Mon Sep 17 00:00:00 2001
From: Jiuqing Song <jisong@microsoft.com>
Date: Fri, 25 Oct 2024 20:55:12 -0700
Subject: [PATCH 6/7] Add test

---
 .../modelApi/common/normalizeParagraphTest.ts | 661 +++++++++++++++++-
 .../test/modelToDom/contentModelToDomTest.ts  |  70 ++
 .../handlers/handleParagraphTest.ts           | 341 +++++++++
 3 files changed, 1071 insertions(+), 1 deletion(-)

diff --git a/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts b/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts
index dea4db38112..de798f6a570 100644
--- a/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelApi/common/normalizeParagraphTest.ts
@@ -6,7 +6,12 @@ import { createSelectionMarker } from '../../../lib/modelApi/creators/createSele
 import { createText } from '../../../lib/modelApi/creators/createText';
 import { normalizeContentModel } from '../../../lib/modelApi/common/normalizeContentModel';
 import { normalizeParagraph } from '../../../lib/modelApi/common/normalizeParagraph';
-import { ReadonlyContentModelParagraph } from 'roosterjs-content-model-types';
+import {
+    ContentModelParagraph,
+    ContentModelSegment,
+    ContentModelSegmentFormat,
+    ReadonlyContentModelParagraph,
+} from 'roosterjs-content-model-types';
 
 describe('Normalize text that contains space', () => {
     function runTest(texts: string[], expected: string[], whiteSpace?: string) {
@@ -829,3 +834,657 @@ describe('Move up format', () => {
         });
     });
 });
+
+describe('Merge text segments', () => {
+    function runTest(
+        input: ContentModelSegment[],
+        expectedResult: ContentModelSegment[],
+        stillHasCache: boolean,
+        expectedParagraphFormat?: ContentModelSegmentFormat
+    ) {
+        const paragraph = createParagraph();
+        const cache = 'CACHE' as any;
+
+        paragraph.cachedElement = cache;
+
+        paragraph.segments = input;
+
+        normalizeParagraph(paragraph);
+
+        const expectedParagraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: expectedResult,
+        };
+
+        if (expectedParagraphFormat) {
+            expectedParagraph.segmentFormat = expectedParagraphFormat;
+        }
+
+        if (stillHasCache) {
+            expectedParagraph.cachedElement = cache;
+        }
+
+        expect(paragraph).toEqual(expectedParagraph);
+    }
+
+    it('Empty paragraph', () => {
+        runTest([], [], true);
+    });
+
+    it('Single text segment', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: {},
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: {},
+                },
+            ],
+            true
+        );
+    });
+
+    it('Two text segments, same format', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abcdef',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, same format, with space - 1', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: ' abc ',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: ' def ',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, same format, with space - 2', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: ' def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc\u00A0def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, different format - 1', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt', italic: true },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt', italic: true },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, different format - 2', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos' }
+        );
+    });
+
+    it('Two text segments, different format - 3', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '14pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '14pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos' }
+        );
+    });
+
+    it('Two text segments, one has link', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: {},
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: {},
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, both have same link', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: {},
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: {},
+                    },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abcdef',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: {},
+                    },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, both have different link', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: { href: 'url1' },
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: { href: 'url2' },
+                    },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: { href: 'url1' },
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    link: {
+                        dataset: {},
+                        format: { href: 'url2' },
+                    },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, one has code', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    code: {
+                        format: {},
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    code: {
+                        format: {},
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments, both have same code', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    code: {
+                        format: {},
+                    },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    code: {
+                        format: {},
+                    },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abcdef',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                    code: {
+                        format: {},
+                    },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments around selection marker', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments after selection marker', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'abcdef',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two text segments before selection marker', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abcdef',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Three text segments with same format', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'ghi',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abcdefghi',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos', fontSize: '12pt' }
+        );
+    });
+
+    it('Two pairs - 1', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'ghi',
+                    format: { fontFamily: 'Aptos', fontSize: '14pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'jkl',
+                    format: { fontFamily: 'Aptos', fontSize: '14pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abcdef',
+                    format: { fontFamily: 'Aptos', fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'ghijkl',
+                    format: { fontFamily: 'Aptos', fontSize: '14pt' },
+                },
+            ],
+            false,
+            { fontFamily: 'Aptos' }
+        );
+    });
+
+    it('Two pairs - 2', () => {
+        runTest(
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontSize: '14pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'ghi',
+                    format: { fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'jkl',
+                    format: { fontSize: '14pt' },
+                },
+            ],
+            [
+                {
+                    segmentType: 'Text',
+                    text: 'abc',
+                    format: { fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'def',
+                    format: { fontSize: '14pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'ghi',
+                    format: { fontSize: '12pt' },
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'jkl',
+                    format: { fontSize: '14pt' },
+                },
+            ],
+            true
+        );
+    });
+});
diff --git a/packages/roosterjs-content-model-dom/test/modelToDom/contentModelToDomTest.ts b/packages/roosterjs-content-model-dom/test/modelToDom/contentModelToDomTest.ts
index 871c1a22baf..cd87a418155 100644
--- a/packages/roosterjs-content-model-dom/test/modelToDom/contentModelToDomTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelToDom/contentModelToDomTest.ts
@@ -104,6 +104,76 @@ describe('contentModelToDom', () => {
         expect((range as RangeSelection).isReverted).toBe(false);
     });
 
+    it('Extract expanded range - range in middle of text', () => {
+        const mockedHandler = jasmine.createSpy('blockGroupChildren');
+        const context = createModelToDomContext(undefined, {
+            modelHandlerOverride: {
+                blockGroupChildren: mockedHandler,
+            },
+        });
+
+        const root = document.createElement('div');
+        const div = document.createElement('div');
+        const text = document.createTextNode('abcd');
+
+        div.appendChild(text);
+        root.appendChild(div);
+
+        context.regularSelection.start = {
+            block: div,
+            segment: text,
+            offset: 1,
+        };
+        context.regularSelection.end = {
+            block: div,
+            segment: text,
+            offset: 3,
+        };
+
+        const range = contentModelToDom(document, root, {} as any, context);
+
+        expect(range!.type).toBe('range');
+        expect((range as RangeSelection).range.startContainer).toBe(text);
+        expect((range as RangeSelection).range.startOffset).toBe(1);
+        expect((range as RangeSelection).range.endContainer).toBe(text);
+        expect((range as RangeSelection).range.endOffset).toBe(3);
+        expect((range as RangeSelection).isReverted).toBe(false);
+    });
+
+    it('Extract range after empty text', () => {
+        const mockedHandler = jasmine.createSpy('blockGroupChildren');
+        const context = createModelToDomContext(undefined, {
+            modelHandlerOverride: {
+                blockGroupChildren: mockedHandler,
+            },
+        });
+
+        const root = document.createElement('div');
+        const div = document.createElement('div');
+        const text = document.createTextNode('');
+
+        div.appendChild(text);
+        root.appendChild(div);
+
+        context.regularSelection.start = {
+            block: div,
+            segment: text,
+        };
+        context.regularSelection.end = {
+            block: div,
+            segment: text,
+        };
+
+        const range = contentModelToDom(document, root, {} as any, context);
+
+        expect(range!.type).toBe('range');
+        expect((range as RangeSelection).range.startContainer).toBe(div);
+        expect((range as RangeSelection).range.startOffset).toBe(0);
+        expect((range as RangeSelection).range.endContainer).toBe(div);
+        expect((range as RangeSelection).range.endOffset).toBe(0);
+        expect((range as RangeSelection).isReverted).toBe(false);
+    });
+
     it('Extract selection range - normal collapsed range with empty text', () => {
         const mockedHandler = jasmine.createSpy('blockGroupChildren');
         const context = createModelToDomContext(undefined, {
diff --git a/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts b/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts
index 74a896ed06c..32daefdcfd1 100644
--- a/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelToDom/handlers/handleParagraphTest.ts
@@ -652,3 +652,344 @@ describe('handleParagraph', () => {
         expect(onSegmentSpy).toHaveBeenCalledWith(parent.lastChild, paragraph, [segment2]);
     });
 });
+
+describe('Handle paragraph and adjust selections', () => {
+    it('Selection is at beginning, followed by BR', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Br',
+                    format: {},
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div><br></div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+    });
+
+    it('Selection is at beginning, followed by Text', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test',
+                    format: {},
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div>test</div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 0,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 0,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.firstChild).toBe(parent.firstChild!.lastChild);
+    });
+
+    it('Selection is in middle of text', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'Text',
+                    text: 'test1',
+                    format: {},
+                },
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test2',
+                    format: {},
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div>test1test2</div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 5,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 5,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.firstChild).toBe(parent.firstChild!.lastChild);
+    });
+
+    it('Selection is at end of text', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'Text',
+                    text: 'test1',
+                    format: {},
+                },
+                {
+                    segmentType: 'SelectionMarker',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Br',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test2',
+                    format: {},
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div>test1<br>test2</div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.lastChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.firstChild).not.toBe(parent.firstChild!.lastChild);
+    });
+
+    it('Selection is in middle of text, expanded', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'Text',
+                    text: 'test1',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test2',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test3',
+                    format: {},
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div>test1test2test3</div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 5,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 10,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.lastChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.firstChild).toBe(parent.firstChild!.lastChild);
+    });
+
+    it('Selection is in front of text, expanded', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'Text',
+                    text: 'test1',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test2',
+                    format: {},
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div>test1test2</div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: null,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 5,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.lastChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.firstChild).toBe(parent.firstChild!.lastChild);
+    });
+
+    it('Selection is at the end of text, expanded', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'Text',
+                    text: 'test1',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test2',
+                    format: {},
+                    isSelected: true,
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div>test1test2</div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 5,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.lastChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.firstChild).toBe(parent.firstChild!.lastChild);
+    });
+
+    it('Selection is in middle of text and BR, expanded', () => {
+        const paragraph: ContentModelParagraph = {
+            blockType: 'Paragraph',
+            format: {},
+            segments: [
+                {
+                    segmentType: 'Text',
+                    text: 'test1',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test2',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Br',
+                    format: {},
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test3',
+                    format: {},
+                    isSelected: true,
+                },
+                {
+                    segmentType: 'Text',
+                    text: 'test4',
+                    format: {},
+                },
+            ],
+        };
+
+        const parent = document.createElement('div');
+        const context = createModelToDomContext();
+
+        handleParagraph(document, parent, paragraph, context, null);
+
+        expect(parent.innerHTML).toBe('<div>test1test2<br>test3test4</div>');
+        expect(context.regularSelection.start).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.firstChild,
+            offset: 5,
+        });
+        expect(context.regularSelection.end).toEqual({
+            block: parent.firstChild,
+            segment: parent.firstChild!.lastChild,
+            offset: 5,
+        });
+        expect(parent.firstChild!.firstChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.lastChild!.nodeType).toBe(Node.TEXT_NODE);
+        expect(parent.firstChild!.firstChild).not.toBe(parent.firstChild!.lastChild);
+    });
+});

From e39ada6100061f1e5be65cdc876658782ed09baf Mon Sep 17 00:00:00 2001
From: Jiuqing Song <jisong@microsoft.com>
Date: Fri, 25 Oct 2024 21:54:56 -0700
Subject: [PATCH 7/7] fix test

---
 .../test/modelApi/editing/mergeModelTest.ts        | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts b/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts
index 7bec42fb72a..78ec1d24aa9 100644
--- a/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts
+++ b/packages/roosterjs-content-model-dom/test/modelApi/editing/mergeModelTest.ts
@@ -4080,12 +4080,7 @@ describe('mergeModel', () => {
                 },
                 {
                     segmentType: 'Text',
-                    text: 'test1',
-                    format: {},
-                },
-                {
-                    segmentType: 'Text',
-                    text: 'new text',
+                    text: 'test1new text',
                     format: {},
                 },
                 marker2,
@@ -4957,12 +4952,7 @@ describe('mergeModel', () => {
                 },
                 {
                     segmentType: 'Text',
-                    text: 'test1',
-                    format: {},
-                },
-                {
-                    segmentType: 'Text',
-                    text: 'new text',
+                    text: 'test1new text',
                     format: {},
                 },
                 marker2,