Filter thread replies to original author only

Only replies from the root post's author are rendered; replies from other
users are skipped. Adds fixture and test for a real-world post with an
other-author reply (3mhypinzezo2l).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

extension.php

@@ -123,7 +123,8 @@ final class BlueskyThreadsExtension extends Minz_Extension {
 			return $fallback;
 		}
 
-		$html = $this->renderThread($data['thread'], true);
+		$rootAuthorDid = $data['thread']['post']['author']['did'] ?? null;
+		$html = $this->renderThread($data['thread'], true, $rootAuthorDid);
 		$this->writeCache($url, $html);
 		return $html;
 	}
@@ -221,7 +222,7 @@ final class BlueskyThreadsExtension extends Minz_Extension {
 	// Thread rendering
 	// -------------------------------------------------------------------------
 
-	private function renderThread(array $node, bool $isRoot): string {
+	private function renderThread(array $node, bool $isRoot, ?string $rootAuthorDid = null): string {
 		if (!isset($node['post'])) {
 			return '';
 		}
@@ -229,13 +230,21 @@ final class BlueskyThreadsExtension extends Minz_Extension {
 		$html = $this->renderPost($node['post'], $isRoot);
 
 		if (!empty($node['replies'])) {
-			$html .= '<div class="bsky-replies" style="border-left:2px solid #e1e8ed;margin-left:24px;padding-left:0;">';
+			$repliesHtml = '';
 			foreach ($node['replies'] as $reply) {
-				if (isset($reply['post'])) {
+				if (!isset($reply['post'])) {
-					$html .= $this->renderThread($reply, false);
+					continue;
 				}
+				if ($rootAuthorDid !== null && ($reply['post']['author']['did'] ?? null) !== $rootAuthorDid) {
+					continue;
+				}
+				$repliesHtml .= $this->renderThread($reply, false, $rootAuthorDid);
+			}
+			if ($repliesHtml !== '') {
+				$html .= '<div class="bsky-replies" style="border-left:2px solid #e1e8ed;margin-left:24px;padding-left:0;">';
+				$html .= $repliesHtml;
+				$html .= '</div>';
 			}
-			$html .= '</div>';
 		}
 
 		return $html;

tests/BlueskyThreadsTest.php

@@ -174,6 +174,25 @@ class BlueskyThreadsTest extends TestCase {
 		$this->assertStringContainsString('View on Bluesky', $html);
 	}
 
+	/**
+	 * A post with only a reply from another user (3mhypinzezo2l fixture) must
+	 * render just the root post — the other-author reply is filtered out.
+	 */
+	public function testOtherAuthorRepliesAreExcluded(): void {
+		$data          = json_decode(file_get_contents(__DIR__ . '/fixtures/thread_3mhypinzezo2l.json'), true);
+		$thread        = $data['thread'];
+		$rootAuthorDid = $thread['post']['author']['did'];
+
+		$html = $this->call('renderThread', $thread, true, $rootAuthorDid);
+
+		$this->assertSame(1, substr_count($html, 'bsky-post'),
+			'Only the root post should be rendered; other-author reply must be excluded');
+		$this->assertSame(0, substr_count($html, 'bsky-replies'),
+			'No replies wrapper should be rendered when all replies are from other authors');
+		$this->assertStringNotContainsString('lasagnazero.bsky.social', $html,
+			'Reply author handle must not appear in output');
+	}
+
 	// -------------------------------------------------------------------------
 	// applyFacets — rich-text rendering
 	// -------------------------------------------------------------------------

tests/fixtures/thread_3mhypinzezo2l.json

@@ -0,0 +1,93 @@
+{
+    "thread": {
+        "$type": "app.bsky.feed.defs#threadViewPost",
+        "post": {
+            "uri": "at://did:plc:d4324t32vfi5xzydqbh2qdj3/app.bsky.feed.post/3mhypinzezo2l",
+            "cid": "bafyreialfdaqkwykiinxzy3xb6qhcenuwsaxi7d6qwzx4zfdyhprzo4s2e",
+            "author": {
+                "did": "did:plc:d4324t32vfi5xzydqbh2qdj3",
+                "handle": "hockeyviz.com",
+                "displayName": "Micah McCurdy ",
+                "avatar": "https://cdn.bsky.app/img/avatar/plain/did:plc:d4324t32vfi5xzydqbh2qdj3/bafkreiddyjdi3hty4z73vdoyxja3hj5n7izrsdmeoif2ppkqidbt4nsluq",
+                "associated": {
+                    "chat": {
+                        "allowIncoming": "all"
+                    },
+                    "activitySubscription": {
+                        "allowSubscriptions": "followers"
+                    }
+                },
+                "labels": [],
+                "createdAt": "2023-05-28T17:07:32.578Z"
+            },
+            "record": {
+                "$type": "app.bsky.feed.post",
+                "createdAt": "2026-03-26T23:01:26.959Z",
+                "facets": [],
+                "langs": [
+                    "en"
+                ],
+                "tags": [],
+                "text": "Any good musician can rerecord somebody else's song but what really makes a cover worth doing is that little note of jealousy nestled in the blanket of admiration. It's the same with reproving somebody else's result or redoing a viz. Shoulda been me, the grudgingist yet in fact highest respect."
+            },
+            "bookmarkCount": 0,
+            "replyCount": 1,
+            "repostCount": 0,
+            "likeCount": 21,
+            "quoteCount": 0,
+            "indexedAt": "2026-03-26T23:01:27.160Z",
+            "labels": []
+        },
+        "replies": [
+            {
+                "$type": "app.bsky.feed.defs#threadViewPost",
+                "post": {
+                    "uri": "at://did:plc:vfi77nom5cwpnhurnxhy7ltj/app.bsky.feed.post/3mhyw2ijjc22a",
+                    "cid": "bafyreif6evbxbqcf5t3t6i4apm6pertxy4mylleet6a2d2fgzwqnz6inly",
+                    "author": {
+                        "did": "did:plc:vfi77nom5cwpnhurnxhy7ltj",
+                        "handle": "lasagnazero.bsky.social",
+                        "displayName": "L0",
+                        "avatar": "https://cdn.bsky.app/img/avatar/plain/did:plc:vfi77nom5cwpnhurnxhy7ltj/bafkreigjurbghqtq3iogsqarnxldhl54zqdmi657pflwrrqwa2wisteq6i",
+                        "associated": {
+                            "activitySubscription": {
+                                "allowSubscriptions": "followers"
+                            }
+                        },
+                        "labels": [],
+                        "createdAt": "2024-11-07T14:26:50.985Z"
+                    },
+                    "record": {
+                        "$type": "app.bsky.feed.post",
+                        "createdAt": "2026-03-27T00:58:47.713Z",
+                        "langs": [
+                            "en",
+                            "ru"
+                        ],
+                        "reply": {
+                            "parent": {
+                                "cid": "bafyreialfdaqkwykiinxzy3xb6qhcenuwsaxi7d6qwzx4zfdyhprzo4s2e",
+                                "uri": "at://did:plc:d4324t32vfi5xzydqbh2qdj3/app.bsky.feed.post/3mhypinzezo2l"
+                            },
+                            "root": {
+                                "cid": "bafyreialfdaqkwykiinxzy3xb6qhcenuwsaxi7d6qwzx4zfdyhprzo4s2e",
+                                "uri": "at://did:plc:d4324t32vfi5xzydqbh2qdj3/app.bsky.feed.post/3mhypinzezo2l"
+                            }
+                        },
+                        "text": "Something about imitation and flattery\u2026"
+                    },
+                    "bookmarkCount": 0,
+                    "replyCount": 0,
+                    "repostCount": 0,
+                    "likeCount": 0,
+                    "quoteCount": 0,
+                    "indexedAt": "2026-03-27T00:58:48.952Z",
+                    "labels": []
+                },
+                "replies": [],
+                "threadContext": {}
+            }
+        ],
+        "threadContext": {}
+    }
+}