feat: support hashtags (#2)

Co-authored-by: Enzo Innocenzi <enzo@innocenzi.dev>

src/Facets/DefaultFacetsResolver.php

@@ -17,6 +17,7 @@ public function resolve(BlueskyService $bluesky, BlueskyPost $post): array
         return [
             ...self::detectMentions($text, $bluesky->getClient()),
             ...self::detectLinks($text),
+            ...self::detectTags($text),
         ];
     }
 
@@ -68,4 +69,32 @@ private static function detectLinks(string $text): array
             );
         }, $matches[1]);
     }
+
+    /** @return array<Facet> */
+    private static function detectTags(string $text): array
+    {
+        $tagRegexp = '/(?:^|\\s)(#[^\\d\\s]\\S*)(?=\\s)?/';
+
+        preg_match_all($tagRegexp, $text, $matches, \PREG_OFFSET_CAPTURE);
+
+        return array_filter(array_map(function (array $match) {
+            [$tag, $position] = $match;
+
+            $tag = preg_replace('/\\p{P}+$/u', '', $tag);
+
+            if (\strlen($tag) > 66) {
+                return null;
+            }
+
+            return new Facet(
+                range: [
+                    $position,
+                    $position + mb_strlen($tag),
+                ],
+                features: [
+                    new Tag(tag: substr($tag, 1)),
+                ],
+            );
+        }, $matches[1]));
+    }
 }

src/Facets/Tag.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace NotificationChannels\Bluesky\Facets;
+
+final class Tag extends Feature
+{
+    public function __construct(
+        public readonly string $tag,
+    ) {
+    }
+
+    public function getType(): string
+    {
+        return 'app.bsky.richtext.facet#tag';
+    }
+}

tests/DefaultFacetsResolverTest.php

@@ -122,3 +122,87 @@
         ]),
     );
 });
+
+it('detects tags', function (string $text, array $positions, string $tag) {
+    /** @var FacetsResolver */
+    $resolver = resolve(FacetsResolver::class);
+    $facets = $resolver->resolve(
+        bluesky: resolve(BlueskyService::class),
+        post: BlueskyPost::make()->text($text),
+    );
+
+    expect($facets)->sequence(
+        fn (Expectation $facet) => $facet->toArray()->toBe([
+            '$type' => 'app.bsky.richtext.facet',
+            'index' => [
+                'byteStart' => $positions[0],
+                'byteEnd' => $positions[1],
+            ],
+            'features' => [
+                [
+                    '$type' => 'app.bsky.richtext.facet#tag',
+                    'tag' => $tag,
+                ],
+            ],
+        ]),
+    );
+})->with([
+    ['A post with a #tag inline', [14, 18], 'tag'],
+    ['#tag starting the post', [0, 4], 'tag'],
+    ['a post ended by a #tag', [18, 22], 'tag'],
+    ['a tag that ends #with! punctuation', [16, 21], 'with'],
+    ['a post with #anextremelylongtagwhichisjustunderblueskys64charactertaglimit!', [12, 74], 'anextremelylongtagwhichisjustunderblueskys64charactertaglimit'],
+]);
+
+it('doesnt detect non tags', function (string $text) {
+    /** @var FacetsResolver */
+    $resolver = resolve(FacetsResolver::class);
+    $facets = $resolver->resolve(
+        bluesky: resolve(BlueskyService::class),
+        post: BlueskyPost::make()->text($text),
+    );
+
+    expect($facets)->toBe([]);
+})->with([
+    ['A real#tag must start with space'],
+    ['a #1tag can not have a number'],
+    ['an #anextremelylongtagwhichisabsolutlyoverblueskys64charactertaglimitisnotaddedasatag'],
+]);
+
+it('detects multiple tags', function () {
+    /** @var FacetsResolver */
+    $resolver = resolve(FacetsResolver::class);
+    $facets = $resolver->resolve(
+        bluesky: resolve(BlueskyService::class),
+        post: BlueskyPost::make()->text('this post has #two #tags'),
+    );
+
+    expect($facets)->sequence(
+        fn (Expectation $facet) => $facet->toArray()->toBe([
+            '$type' => 'app.bsky.richtext.facet',
+            'index' => [
+                'byteStart' => 14,
+                'byteEnd' => 18,
+            ],
+            'features' => [
+                [
+                    '$type' => 'app.bsky.richtext.facet#tag',
+                    'tag' => 'two',
+                ],
+            ],
+        ]),
+        fn (Expectation $facet) => $facet->toArray()->toBe([
+            '$type' => 'app.bsky.richtext.facet',
+            'index' => [
+                'byteStart' => 19,
+                'byteEnd' => 24,
+            ],
+            'features' => [
+                [
+                    '$type' => 'app.bsky.richtext.facet#tag',
+                    'tag' => 'tags',
+                ],
+            ],
+        ]),
+    );
+});