Add knip checks

Author: kvz

.github/workflows/ci.yml

@@ -38,6 +38,17 @@ jobs:
       - run: corepack yarn
       - run: corepack yarn lint:js
 
+  knip:
+    name: Knip
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      - run: corepack yarn
+      - run: corepack yarn knip
+
   typescript:
     name: Lint (TypeScript)
     runs-on: ubuntu-latest

knip.ts

@@ -0,0 +1,39 @@
+import type { KnipConfig } from 'knip'
+
+// Note: `yarn check` runs knip with --fix --allow-remove-files. This is safe because
+// lint:ts and tests run immediately after - they'll fail if knip removes something needed.
+const config: KnipConfig = {
+  entry: [
+    'src/**/*.{ts,tsx,js,jsx}',
+    'test/**/*.{ts,tsx,js,jsx}',
+    'scripts/**/*.{ts,tsx,js,jsx}',
+    'vitest.config.ts',
+  ],
+  project: ['{src,test,scripts}/**/*.{ts,tsx,js,jsx}'],
+  ignore: [
+    'dist/**',
+    'coverage/**',
+    'static-build/**',
+    'node_modules/**',
+    // alphalib is a shared utility library. Exclude it so knip does not remove
+    // files that may only be used in other repos.
+    'src/alphalib/**',
+  ],
+  ignoreDependencies: [
+    // Used in src/alphalib/** which is excluded from knip
+    '@aws-sdk/client-s3',
+    '@aws-sdk/s3-request-presigner',
+    '@transloadit/sev-logger',
+    'type-fest',
+    'zod',
+    // Repo-specific ignores
+    '@types/minimist',
+    'minimatch',
+    'tsx',
+  ],
+  rules: {
+    duplicates: 'warn',
+  },
+}
+
+export default config

package.json

@@ -32,18 +32,21 @@
     "p-queue": "^9.0.1",
     "recursive-readdir": "^2.2.3",
     "tus-js-client": "^4.3.1",
+    "typanion": "^3.14.0",
     "type-fest": "^4.41.0",
     "zod": "3.25.76"
   },
   "devDependencies": {
     "@biomejs/biome": "^2.2.4",
     "@types/debug": "^4.1.12",
+    "@types/node": "^24.10.3",
     "@types/recursive-readdir": "^2.2.4",
     "@types/temp": "^0.9.4",
     "@vitest/coverage-v8": "^3.2.4",
     "badge-maker": "^5.0.2",
     "execa": "9.6.0",
     "image-size": "^2.0.2",
+    "knip": "^5.73.3",
     "minimatch": "^10.1.1",
     "nock": "^14.0.10",
     "npm-run-all": "^4.1.5",
@@ -62,13 +65,16 @@
     "src": "./src"
   },
   "scripts": {
-    "check": "yarn lint:ts && yarn fix && yarn test:unit",
+    "check": "yarn knip --fix --allow-remove-files --no-config-hints && yarn lint:ts && yarn fix && yarn test:unit",
     "fix:js": "biome check --write .",
     "lint:ts": "tsc --build",
     "fix:js:unsafe": "biome check --write . --unsafe",
     "lint:js": "biome check .",
     "lint": "npm-run-all --parallel 'lint:js'",
     "fix": "npm-run-all --serial 'fix:js'",
+    "lint:deps": "knip --dependencies --no-progress",
+    "fix:deps": "knip --dependencies --no-progress --fix",
+    "knip": "knip --no-config-hints --no-progress",
     "prepack": "rm -f tsconfig.tsbuildinfo tsconfig.build.tsbuildinfo && tsc --build tsconfig.build.json",
     "test:unit": "vitest run --coverage ./test/unit",
     "test:e2e": "vitest run ./test/e2e",