Enable noUncheckedIndexedAccess and fix all 98 call sites it surfaced across 18
files. Every fix is behaviour-preserving — the flag flagged reads TypeScript
couldn't prove in-bounds, all of which were already guarded by a length/index check,
a findIndex result, or a non-empty invariant:
- read-once so a ternary's narrowing sticks (Feed overrides, linkify mention);
- non-null assertion AFTER an existing guard (PlayerModal/VideoEditor queue+cut-list
indexing, modules step, useUndoable stacks) with a comment stating the invariant;
- nullish fallback where undefined is a real possibility (GlassTuner slider ?? def,
ConfigPanel active group ?? [], descriptionLinks id ?? null);
- optional chaining where the entry genuinely can be absent (PlexBrowse IO entry);
- a non-empty tuple type for the RELATIVE_UNITS constant (encodes "always has [0]").
The single highest-leverage fix: PlayerModal's `active` became `queue?.[index] ??
video` (always Video), clearing 34 of the 45 errors in that file at once. Verified:
tsc/eslint/prettier clean, 56 vitest + 34 pytest + 17/17 e2e green (the e2e suite
exercises the feed/player/channel components touched here).
Three strictness flags that the codebase already satisfies (0 errors each):
- noFallthroughCasesInSwitch on src + e2e — a missing `break` is now a type error.
- noUnusedLocals + noUnusedParameters on the e2e project, so it matches src and node
and dead spec scaffolding can't accumulate (it was the one project without them).
- allowJs + checkJs on the node project, pulling tailwind.config.js and
postcss.config.js under the type checker (the last hole in C-4.5) — a real type
error in either is now caught (verified: `content: 123` fails; Config stays
permissive on plugin keys by design).
noUncheckedIndexedAccess is NOT here — it has 98 call-site fixes and lands as its own
reviewable sub-sprint (S3b).
Review round 1 fallout, all of it verified against real builds:
- .dockerignore: `node_modules/` is anchored at the context root and has no
implicit `**/` (unlike gitignore), so it never matched frontend/node_modules.
`COPY frontend/ ./` was overlaying the Windows host's node_modules on top of
what `npm ci` had installed — the image carried @esbuild/win32-x64 and 31 .cmd
shims, and the new typecheck ran a tsc resolved from that merged tree. Build
context transfer drops 3.05 GB -> 19 kB. Also excludes e2e/.auth (a live
Playwright session), the report/result dirs and logs.
- build no longer type-checks the e2e project: a type error in a spec must not
make the app unbuildable for a self-hoster. The gate still checks it via
`npm run typecheck` (now three named lanes).
- tsconfig.json references tsconfig.node.json, so editors check vite.config.ts /
vitest.config.ts under the same config the gate uses instead of an inferred one.
- vitest include accepts .test.tsx: an uncollected test file does not fail, it
silently never runs.
- Vite + React + TS + Tailwind SPA served by FastAPI (multi-stage Docker build)
- Four color schemes (Midnight default, Forest, Slate, YouTube) x dark/light,
adjustable text size; persisted to user preferences and localStorage
- Header search, grid/list toggle, theme menu; sidebar filters (show state,
sort, include Shorts/live, language + topic tag chips with any/all matching)
- Infinite-scroll feed of video cards; click opens youtube.com in a new tab;
per-video watched / saved / hidden actions with optimistic updates
- SPA fallback routing; login screen for unauthenticated users
peter