v3: comments say what the code can't — the documentation pass wanted JSDoc on every export and every field of an exported interface, which filled the code with restatements ("The dump.", "Whether it is loading.", "The props of X.", "Renders the X.") and module docs that told a reader nothing ("The hot and new feeds, and the props every main feed of the index takes."); some were wrong as well as vague. Every comment in api/, shared/ and src/ is rewritten under one rule, now stated in the README's "Comments" section: every module and export still has a JSDoc, and it gives context (who uses it and where), usage (what a caller must know: a precondition, what it leaves to the caller, a side effect) or its place in the chain (where its input comes from, where its output goes); a field, parameter, private function or local gets one only when it adds to its parent's, and context about a whole type goes on the type; a type's doc is phrased from the value's side ("Returned to Y by X when Z", "Passed to Y by X"); full sentences, as short as they can be, no label-colon-list; // goes wherever the code isn't obvious and says why, and the section banners and narration go. Every claim was checked against the code, which turned up some forty comments that were wrong: DumpCard's claimed it was only used by the hot and new feeds, the WebSocket welcome claimed to be a socket's first message (presence comes first), UpdateUserRequest said null removes a description (it keeps it), deletedDumpIds leaves out that it also holds dumps made private, THEME_COLOR claimed to mirror index.html's, and the like. The routers' JSDoc now says where they are mounted and what becomes of a thrown APIException. doc-lint.ts lets a field without a doc through; a module or export without one still fails. No code changes; 204 backend and 628 frontend tests pass, and doc:lint, deno check, deno lint and tsc are clean.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/utils/chat/text.ts

@@ -1,5 +1,6 @@
 /**
- * Text helpers for the live chat.
+ * Reads the Markdown of chat messages, to find mentions and to flatten it into
+ * reply previews.
  *
  * @module
  */
@@ -7,8 +8,9 @@
 import { MENTION_RE } from "../../../shared/mention.ts";
 
 /**
- * Checks whether `body` @-mentions `username` (case-insensitively), by the same
- * rule the server uses to send mention notifications.
+ * Checks whether `body` @mentions `username`, ignoring case, with the pattern
+ * the server uses for mention notifications. `WSProvider` uses it to pick the
+ * chime, and `ChatModal` to highlight the message.
  */
 export function mentionsUser(body: string, username: string): boolean {
   const target = username.toLowerCase();
@@ -19,14 +21,15 @@ export function mentionsUser(body: string, username: string): boolean {
 }
 
 /**
- * Returns the chat markdown `md` flattened to one line of plain text, for the
- * reply previews: images become their alt text or `imageLabel`, links their
- * text, and markup characters go. Also copes with a body the server cut short
- * mid-link, which would otherwise show a dangling half-URL.
+ * Returns the Markdown `md` as one line of plain text. Images become their alt
+ * text, or `imageLabel` without one, and links their text. It takes a
+ * `replyToBody`, which the server cuts short, possibly inside a link: the
+ * unfinished link then shows as its text, without half a URL. `snippet` calls
+ * it.
  */
 export function markdownToPlainText(md: string, imageLabel: string): string {
   return md
-    // A truncated image or link at the very end: drop the unfinished target.
+    // An image or link cut short at the end loses its unfinished target.
     .replace(/!\[([^\]]*)\]\([^)]*$/, (_, alt: string) => alt || imageLabel)
     .replace(/(^|[^!])\[([^\]]*)\]\([^)]*$/, "$1$2")
     .replace(/!\[[^\]]*$/, "")