v3: src/ is documented like api/ and shared/, and the reference covers the whole repository — the frontend had no module docs, JSDoc on some components and hooks and not on others, props typed inline in half the components and in private interfaces in the rest, // comments on declarations, and no return types on 147 exported functions, so deno doc --lint over src/ found 637 errors. The rule api/ follows is applied to every non-test module of src/: a /** … @module */ block, JSDoc on every export and every field of an exported interface, /** */ for declarations and // for notes, verbs for functions ("Renders…" for a component), parameters named in the prose, {@link} only for symbols in scope, and a page's JSDoc names its route and who may see it (App.tsx's module doc lists the route table). For deno doc to show them, every exported function states its return type: components React.JSX.Element (or | null, or a portal), memo and forwardRef components their exotic types, contexts React.Context<…>, and a hook returning several things a documented Use<Name>Result interface (useAuth, useRequiredAuth, useFading, useEmojiTrigger, useMentionAutocomplete, useDumpCardLink, usePlayRichContent; FeedCacheResult, YouTubePlaylistControls and UseApiFormReturn are renamed to match). Every component that takes props takes an exported, documented <Name>Props interface — the 64 inline prop types are lifted into one, DumpFeed gets DumpFeedProps extending MainFeedProps. React types go through the global React namespace: the four default imports of react are gone, since deno doc can't follow them. Two duplicates go too: useMentionAutocomplete's UserResult was shared/'s UserSuggestion, and JournalCard re-exported JournalShape for no one; i18n.ts no longer re-exports Lingui's i18n, which its three users now import from @lingui/core. deno task doc and doc:lint now take src/ (but its tests and the generated locales), the index page gains a Frontend section linking every module by layer and domain, mod.test.ts walks src/ as well, and the docs workflow runs on changes to src/. deno doc doesn't document npm packages, so it takes a type imported from one — react-hook-form's FieldValues in the form fields, frimousse's SkinTone — for a private one; doc:lint now goes through doc-lint.ts, which fails on every diagnostic but those, 25 of them. The README states the frontend's part of the rule. No behaviour changes; 205 backend and 628 frontend tests pass, and tsc, deno check and deno lint are clean.

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

src/components/social/FollowButton.tsx

@@ -1,21 +1,37 @@
+/**
+ * The follow buttons, for a user and for a playlist.
+ *
+ * @module
+ */
+
 import { t } from "@lingui/core/macro";
 import { Trans } from "@lingui/react/macro";
 import { useAuth } from "../../hooks/auth/useAuth.ts";
 import { useFollows } from "../../hooks/social/useFollows.ts";
 
-interface FollowUserButtonProps {
+/** The props of {@link FollowUserButton}. */
+export interface FollowUserButtonProps {
+  /** The user's id. */
   targetUserId: string;
+  /** The user's name, for the button's label. */
   targetUsername: string;
 }
 
-interface FollowPlaylistButtonProps {
+/** The props of {@link FollowPlaylistButton}. */
+export interface FollowPlaylistButtonProps {
+  /** The playlist's id. */
   targetPlaylistId: string;
+  /** Whether it is public; only a public playlist can be followed. */
   isPublic: boolean;
 }
 
+/**
+ * Renders the button that follows or unfollows a user; nothing when signed out
+ * or on one's own profile.
+ */
 export function FollowUserButton(
   { targetUserId, targetUsername }: FollowUserButtonProps,
-) {
+): React.JSX.Element | null {
   const { user } = useAuth();
   const { followedUserIds, followUser, unfollowUser, isLoaded } = useFollows();
 
@@ -39,9 +55,13 @@ export function FollowUserButton(
   );
 }
 
+/**
+ * Renders the button that follows or unfollows a playlist; nothing when signed
+ * out or for a private playlist.
+ */
 export function FollowPlaylistButton(
   { targetPlaylistId, isPublic }: FollowPlaylistButtonProps,
-) {
+): React.JSX.Element | null {
   const { user } = useAuth();
   const { followedPlaylistIds, followPlaylist, unfollowPlaylist, isLoaded } =
     useFollows();