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>

api/services/comment-like-service.ts

@@ -1,5 +1,9 @@
 /**
- * Likes on comments.
+ * Stores likes on comments and keeps each comment's `like_count` in step with
+ * them. Likes have no HTTP endpoint to cast or remove. The WebSocket route
+ * (`routes/ws.ts`) calls this module on `comment_like_cast` and
+ * `comment_like_remove` messages, then broadcasts the new count. The comment
+ * routes use it only to list a comment's likers.
  *
  * @module
  */
@@ -11,16 +15,19 @@ import { db } from "../db/connection.ts";
 import { type Page, pageOf } from "../lib/pagination.ts";
 import { notifyCommentOwnerLike } from "./notification-service.ts";
 
-/** A comment's likes after a like was cast or removed. */
+/**
+ * Returned to the WebSocket route by {@link castCommentLike} and
+ * {@link removeCommentLike}. The route acks the liker with `likeCount`, then
+ * broadcasts it to every client, or to the liker's alone when the comment's
+ * dump `isPrivate`.
+ */
 export interface LikeResult {
-  /** The comment's like count now. */
   likeCount: number;
-  /** Whether the comment's dump is private: its likes go to the dump's owner only. */
   isPrivate: boolean;
 }
 
 /**
- * Returns whether the comment's dump is private, or throws a 404 when the user
+ * Returns whether the comment's dump is private, or throws a 404 when `userId`
  * can't see it.
  */
 function commentVisibility(commentId: string, userId: string): boolean {
@@ -35,7 +42,8 @@ function commentVisibility(commentId: string, userId: string): boolean {
 }
 
 /**
- * Records `userId`'s like on a comment and notifies its author.
+ * Records `userId`'s like on a comment and notifies the comment's author. The
+ * notification is best-effort: if it fails, the like still counts.
  *
  * @throws {APIException} 404 when the comment doesn't exist or sits on someone
  * else's private dump, 409 when the user already likes it.
@@ -72,7 +80,7 @@ export function castCommentLike(
     }
     throw err;
   }
-  // Notification is best-effort — must not prevent like_ack from being sent
+  // The like is committed: a failed notification must not report it as failed.
   try {
     notifyCommentOwnerLike(userId, commentId);
   } catch { /* ignore */ }
@@ -80,8 +88,9 @@ export function castCommentLike(
 }
 
 /**
- * Takes back `userId`'s like on a comment. No visibility check: taking back a
- * like is harmless, and it's the user's own row.
+ * Takes back `userId`'s like on a comment. It doesn't check that the user can
+ * still see the comment, since a like on a dump that has gone private is still
+ * theirs to take back.
  *
  * @throws {APIException} 404 when the user doesn't like the comment.
  */
@@ -118,7 +127,11 @@ export function removeCommentLike(
   }
 }
 
-/** Returns the ids of every comment `userId` likes. */
+/**
+ * Returns the ids of the comments `userId` likes. The WebSocket route sends
+ * them in its `welcome` message, and the client shows those like buttons
+ * pressed.
+ */
 export function getUserCommentLikes(userId: string): string[] {
   const rows = db.prepare(
     `SELECT comment_id FROM comment_likes WHERE user_id = ?;`,
@@ -126,7 +139,13 @@ export function getUserCommentLikes(userId: string): string[] {
   return rows.map((r) => r.comment_id);
 }
 
-/** Returns a page of the users who like a comment, latest first. */
+/**
+ * Returns a page of the users who like a comment, latest like first, for
+ * `GET /api/comments/:commentId/likers`. It doesn't check that the caller may
+ * see the comment: the route does that first, with `getDump`.
+ *
+ * @throws {APIException} 500 when a row doesn't parse as a user.
+ */
 export function getCommentLikers(
   commentId: string,
   page: number,