From 933408a0fb588a74a084563c3728b904bf9b7b16 Mon Sep 17 00:00:00 2001
From: Rick Caplan <rick.caplan@shopify.com>
Date: Tue, 14 Jan 2025 21:26:38 +0000
Subject: [PATCH] updates localized field hooks and tests

---
 .../checkout/hooks/localized-fields.ts        | 19 ++--
 .../hooks/tests/localized-fields.test.ts      | 87 +++++++++++++++++--
 2 files changed, 93 insertions(+), 13 deletions(-)

diff --git a/packages/ui-extensions-react/src/surfaces/checkout/hooks/localized-fields.ts b/packages/ui-extensions-react/src/surfaces/checkout/hooks/localized-fields.ts
index 710d60bb3..3eb00601a 100644
--- a/packages/ui-extensions-react/src/surfaces/checkout/hooks/localized-fields.ts
+++ b/packages/ui-extensions-react/src/surfaces/checkout/hooks/localized-fields.ts
@@ -15,7 +15,7 @@ import {useSubscription} from './subscription';
  */
 export function useLocalizedFields<
   Target extends RenderExtensionTarget = RenderExtensionTarget,
->(keys: LocalizedFieldKey[]): (LocalizedField | undefined)[] | undefined {
+>(keys?: LocalizedFieldKey[]): LocalizedField[] {
   const {localizedFields} = useApi<Target>();
 
   if (!localizedFields) {
@@ -27,10 +27,19 @@ export function useLocalizedFields<
   const localizedFieldsData = useSubscription(localizedFields);
 
   if (!keys?.length) {
-    return undefined;
+    return localizedFieldsData;
   }
 
-  return keys.map((key) => {
-    return localizedFieldsData?.find(({key: fieldKey}) => fieldKey === key);
-  });
+  return localizedFieldsData.filter(({key}) => keys.includes(key));
+}
+
+/**
+ * Returns the current localized field or undefined for the specified
+ * localized field key and re-renders your component if the value changes.
+ */
+export function useLocalizedField<
+  Target extends RenderExtensionTarget = RenderExtensionTarget,
+>(key: LocalizedFieldKey): LocalizedField | undefined {
+  const fields = useLocalizedFields<Target>([key]);
+  return fields[0];
 }
diff --git a/packages/ui-extensions-react/src/surfaces/checkout/hooks/tests/localized-fields.test.ts b/packages/ui-extensions-react/src/surfaces/checkout/hooks/tests/localized-fields.test.ts
index 3e683fab3..1fe2e7a50 100644
--- a/packages/ui-extensions-react/src/surfaces/checkout/hooks/tests/localized-fields.test.ts
+++ b/packages/ui-extensions-react/src/surfaces/checkout/hooks/tests/localized-fields.test.ts
@@ -1,6 +1,6 @@
 import type {LocalizedField} from '@shopify/ui-extensions/checkout';
 
-import {useLocalizedFields} from '../localized-fields';
+import {useLocalizedFields, useLocalizedField} from '../localized-fields';
 
 import {mount, createMockStatefulRemoteSubscribable} from './mount';
 
@@ -19,7 +19,30 @@ describe('useLocalizedFields', () => {
     );
   });
 
-  it('returns an array containing undefined if no localized fields match the passed keys', () => {
+  it('returns all localized fields if no keys are passed', () => {
+    const localizedFields: LocalizedField[] = [
+      {
+        key: 'TAX_CREDENTIAL_BR',
+        title: 'CPF/CNPJ',
+        value: 'test-value',
+      },
+      {
+        key: 'SHIPPING_CREDENTIAL_BR',
+        title: 'CPF/CNPJ',
+        value: 'test-value',
+      },
+    ];
+
+    const extensionApi = {
+      localizedFields: createMockStatefulRemoteSubscribable(localizedFields),
+    };
+
+    const {value} = mount.hook(() => useLocalizedFields(), {extensionApi});
+
+    expect(value).toStrictEqual(localizedFields);
+  });
+
+  it('returns an empty array if no localized fields match the passed keys', () => {
     const localizedFields: LocalizedField[] = [
       {
         key: 'TAX_CREDENTIAL_BR',
@@ -76,7 +99,7 @@ describe('useLocalizedFields', () => {
     expect(value).toMatchObject([localizedFields[0], localizedFields[2]]);
   });
 
-  it('returns an array of localized fields for matching fields and undefined for non-matching fields', () => {
+  it('returns an array of localized fields for any matching fields', () => {
     const localizedFields: LocalizedField[] = [
       {
         key: 'TAX_CREDENTIAL_MX',
@@ -109,10 +132,58 @@ describe('useLocalizedFields', () => {
       {extensionApi},
     );
 
-    expect(value).toMatchObject([
-      localizedFields[0],
-      undefined,
-      localizedFields[2],
-    ]);
+    expect(value).toMatchObject([localizedFields[0], localizedFields[2]]);
+  });
+});
+
+describe('useLocalizedField', () => {
+  it('returns the localized field that matches the passed key', async () => {
+    const localizedFields: LocalizedField[] = [
+      {
+        key: 'TAX_CREDENTIAL_MX',
+        title: 'Tax credential MX',
+        value: 'test-value-1',
+      },
+      {
+        key: 'SHIPPING_CREDENTIAL_MX',
+        title: 'Shipping credential MX',
+        value: 'test-value-2',
+      },
+      {
+        key: 'TAX_CREDENTIAL_USE_MX',
+        title: 'Tax credential use MX',
+        value: 'test-value-3',
+      },
+    ];
+
+    const extensionApi = {
+      localizedFields: createMockStatefulRemoteSubscribable(localizedFields),
+    };
+
+    const {value} = mount.hook(
+      () => useLocalizedField('TAX_CREDENTIAL_USE_MX'),
+      {
+        extensionApi,
+      },
+    );
+
+    expect(value).toStrictEqual(localizedFields[2]);
+  });
+
+  it('returns undefined if no localized field matches the passed key', async () => {
+    const localizedFields: LocalizedField[] = [];
+
+    const extensionApi = {
+      localizedFields: createMockStatefulRemoteSubscribable(localizedFields),
+    };
+
+    const {value} = mount.hook(
+      () => useLocalizedField('TAX_CREDENTIAL_USE_MX'),
+      {
+        extensionApi,
+      },
+    );
+
+    expect(value).toBeUndefined();
   });
 });