chore: Introduce Knip (#18005)

* chore: add Knip + config

* chore: use named exports consistently (only shorthands)

* chore: update Knip & reduce config (by improved 11ty plugin)

* chore: rename `lint:knip` → `lint:imports`

Co-authored-by: Nicholas C. Zakas <nicholas@humanwhocodes.com>

* chore: upgrade Knip to v4.3.0

* chore: fix createCoreRuleConfigs import in test

* chore: annotate default export for runtime-info (to satisfy both proxyquire and knip)

* chore: update knip.jsonc

Co-authored-by: Josh Goldberg ✨ <git@joshuakgoldberg.com>

* chore: add comment to export/import hint

* chore: upgrade Knip to v5.0.1 (no breaking changes)

* chore: remove unused files, dependencies & exports

* chore: fix whitespace in ci.yml

* chore: add Knip to CI job

* Remove tools/update-rule-types.js from knip.jsonc

Co-authored-by: Milos Djermanovic <milos.djermanovic@gmail.com>

* Add corrected shared/types Rule import to lazy-loading-rule-map.js

* Added back eslint-plugin-* devDependencies

* Rename to lint:unused

* Fix introduced prism-eslint-hook complaints

---------

Co-authored-by: Nicholas C. Zakas <nicholas@humanwhocodes.com>
Co-authored-by: Josh Goldberg ✨ <git@joshuakgoldberg.com>
Co-authored-by: Milos Djermanovic <milos.djermanovic@gmail.com>

.github/workflows/ci.yml

@@ -13,32 +13,34 @@ jobs:
     name: Verify Files
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-node@v4
-      with:
-        node-version: 'lts/*'
-    - name: Install Packages
-      run: npm install --force
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "lts/*"
+      - name: Install Packages
+        run: npm install --force
 
-    - name: Install Docs Packages
-      working-directory: docs
-      run: npm install
+      - name: Install Docs Packages
+        working-directory: docs
+        run: npm install
 
-    - name: Lint Files
-      run: node Makefile lint
+      - name: Lint Files
+        run: node Makefile lint
 
-    - name: Check Rule Files
-      run: node Makefile checkRuleFiles
+      - name: Check Rule Files
+        run: node Makefile checkRuleFiles
 
-    - name: Check Licenses
-      run: node Makefile checkLicenses
+      - name: Check Licenses
+        run: node Makefile checkLicenses
 
-    - name: Lint Docs JS Files
-      run: node Makefile lintDocsJS
+      - name: Lint Docs JS Files
+        run: node Makefile lintDocsJS
 
-    - name: Check Rule Examples
-      run: node Makefile checkRuleExamples
+      - name: Check Rule Examples
+        run: node Makefile checkRuleExamples
 
+      - name: Lint Files, Dependencies, & Exports
+        run: npm run lint:unused
 
   test_on_node:
     name: Test
@@ -47,40 +49,40 @@ jobs:
         os: [ubuntu-latest]
         node: [21.x, 20.x, 18.x, "18.18.0"]
         include:
-        - os: windows-latest
-          node: "lts/*"
-        - os: macOS-latest
-          node: "lts/*"
+          - os: windows-latest
+            node: "lts/*"
+          - os: macOS-latest
+            node: "lts/*"
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-node@v4
-      with:
-        node-version: ${{ matrix.node }}
-    - name: Install Packages
-      run: npm install --force
-    - name: Test
-      run: node Makefile mocha
-    - name: Fuzz Test
-      run: node Makefile fuzz
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+      - name: Install Packages
+        run: npm install --force
+      - name: Test
+        run: node Makefile mocha
+      - name: Fuzz Test
+        run: node Makefile fuzz
 
   test_on_browser:
     name: Browser Test
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-node@v4
-      with:
-        node-version: '20' # Should be the same as the version used on Netlify to build the ESLint Playground
-    - name: Install Packages
-      run: npm install --force
-    - name: Test
-      run: node Makefile wdio
-    - name: Fuzz Test
-      run: node Makefile fuzz
-    - uses: actions/upload-artifact@v3
-      if: failure()
-      with:
-        name: logs
-        path: |
-          wdio-logs/*.log
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20" # Should be the same as the version used on Netlify to build the ESLint Playground
+      - name: Install Packages
+        run: npm install --force
+      - name: Test
+        run: node Makefile wdio
+      - name: Fuzz Test
+        run: node Makefile fuzz
+      - uses: actions/upload-artifact@v3
+        if: failure()
+        with:
+          name: logs
+          path: |
+            wdio-logs/*.log

Makefile.js

@@ -532,8 +532,8 @@ target.lintDocsJS = function([fix = false] = []) {
 };
 
 target.fuzz = function({ amount = 1000, fuzzBrokenAutofixes = false } = {}) {
-    const fuzzerRunner = require("./tools/fuzzer-runner");
-    const fuzzResults = fuzzerRunner.run({ amount, fuzzBrokenAutofixes });
+    const { run } = require("./tools/fuzzer-runner");
+    const fuzzResults = run({ amount, fuzzBrokenAutofixes });
 
     if (fuzzResults.length) {
 

bin/eslint.js

@@ -149,7 +149,8 @@ ${getErrorMessage(error)}`;
     }
 
     // Otherwise, call the CLI.
-    const exitCode = await require("../lib/cli").execute(
+    const cli = require("../lib/cli");
+    const exitCode = await cli.execute(
         process.argv,
         process.argv.includes("--stdin") ? await readStdin() : null,
         true

docs/.eleventy.js

@@ -16,7 +16,7 @@ const {
 } = require("luxon");
 const markdownIt = require("markdown-it");
 const markdownItRuleExample = require("./tools/markdown-it-rule-example");
-const { addContentMustBeMarked } = require("./tools/prism-eslint-hook");
+const prismESLintHook = require("./tools/prism-eslint-hook");
 
 module.exports = function(eleventyConfig) {
 
@@ -197,7 +197,7 @@ module.exports = function(eleventyConfig) {
     const ruleExampleOptions = markdownItRuleExample({
         open({ type, code, parserOptions, env, codeBlockToken }) {
 
-            addContentMustBeMarked(codeBlockToken.content, parserOptions);
+            prismESLintHook.addContentMustBeMarked(codeBlockToken.content, parserOptions);
 
             const isRuleRemoved = !Object.hasOwn(env.rules_meta, env.title);
 

docs/package.json

@@ -35,20 +35,15 @@
         "autoprefixer": "^10.4.13",
         "cross-env": "^7.0.3",
         "cssnano": "^5.1.14",
-        "dom-parser": "^0.1.6",
         "eleventy-plugin-nesting-toc": "^1.3.0",
-        "eleventy-plugin-page-assets": "^0.3.0",
-        "eleventy-plugin-reading-time": "^0.0.1",
         "github-slugger": "^1.5.0",
         "hyperlink": "^5.0.4",
-        "imagemin": "^8.0.1",
         "imagemin-cli": "^7.0.0",
         "js-yaml": "^3.14.1",
         "luxon": "^2.4.0",
         "markdown-it": "^12.2.0",
         "markdown-it-anchor": "^8.1.2",
         "markdown-it-container": "^3.0.0",
-        "netlify-cli": "^10.3.1",
         "npm-run-all2": "^5.0.0",
         "postcss-cli": "^10.0.0",
         "postcss-html": "^1.5.0",

docs/src/_plugins/md-syntax-highlighter.js

@@ -26,7 +26,9 @@ SOFTWARE.
 
 const Prism = require("prismjs");
 const loadLanguages = require("prismjs/components/");
-require("../../tools/prism-eslint-hook").installPrismESLintMarkerHook();
+const prismESLintHook = require("../../tools/prism-eslint-hook");
+
+prismESLintHook.installPrismESLintMarkerHook();
 
 /**
  *

knip.jsonc

@@ -0,0 +1,52 @@
+{
+    "workspaces": {
+        ".": {
+            // These entries are complementary to the ones found in package.json
+            "entry": [
+                "lib/rules/index.js",
+                "tools/internal-rules/index.js",
+                // https://github.com/webpro/knip/issues/464
+                // Remove when Knip has a wdio plugin
+                "wdio.conf.js"
+            ],
+            "project": ["{conf,lib,tools}/**/*.js"],
+            "mocha": {
+                "entry": [
+                    "tests/{bin,conf,lib,tools}/**/*.js", // see Makefile.js
+                    "tests/_utils/test-lazy-loading-rules.js"
+                ],
+                "project": ["tests/**/*.js"]
+            },
+            "ignore": [
+                // If Knip would consider exports as named, their usage is too dynamic: globals[`es${ecmaVersion}`]
+                // An alternative is to add `__esModule: true` to the export and we can remove it here from the ignores:
+                "conf/globals.js",
+                // These contain unresolved imports and other oddities:
+                "tests/bench/large.js",
+                "tests/lib/rule-tester/rule-tester.js",
+                "tests/performance/jshint.js",
+                // Many are required using dynamic paths such as `fs.readFileSync(path.join())`:
+                "tests/fixtures/**"
+            ],
+            "ignoreDependencies": [
+                "c8",
+
+                // These will be removed in https://github.com/eslint/eslint/pull/18011
+                "eslint-plugin-eslint-comments",
+                "eslint-plugin-jsdoc",
+                "eslint-plugin-n",
+                "eslint-plugin-unicorn",
+
+                // Ignore until Knip has a wdio plugin:
+                "@wdio/*",
+                "rollup-plugin-node-polyfills"
+            ]
+        },
+        "docs": {
+            "ignore": ["src/assets/js/search.js", "_examples/**"]
+        },
+        // Workspaces with default configs:
+        "packages/*": {},
+        "tools/internal-rules": {}
+    }
+}

lib/config/flat-config-schema.js

@@ -588,6 +588,5 @@ const flatConfigSchema = {
 
 module.exports = {
     flatConfigSchema,
-    assertIsRuleSeverity,
-    assertIsRuleOptions
+    assertIsRuleSeverity
 };

lib/eslint/eslint-helpers.js

@@ -907,7 +907,6 @@ function getCacheFile(cacheFile, cwd) {
 //-----------------------------------------------------------------------------
 
 module.exports = {
-    isGlobPattern,
     findFiles,
 
     isNonEmptyString,

lib/linter/index.js

@@ -1,13 +1,11 @@
 "use strict";
 
 const { Linter } = require("./linter");
-const { interpolate } = require("./interpolate");
 const SourceCodeFixer = require("./source-code-fixer");
 
 module.exports = {
     Linter,
 
     // For testers.
-    SourceCodeFixer,
-    interpolate
+    SourceCodeFixer
 };

lib/linter/linter.js

@@ -58,8 +58,6 @@ const { LATEST_ECMA_VERSION } = require("../../conf/ecma-version");
 // Typedefs
 //------------------------------------------------------------------------------
 
-/** @typedef {InstanceType<import("../cli-engine/config-array").ConfigArray>} ConfigArray */
-/** @typedef {InstanceType<import("../cli-engine/config-array").ExtractedConfig>} ExtractedConfig */
 /** @typedef {import("../shared/types").ConfigData} ConfigData */
 /** @typedef {import("../shared/types").Environment} Environment */
 /** @typedef {import("../shared/types").GlobalConf} GlobalConf */

lib/rule-tester/index.js

@@ -1,5 +1,7 @@
 "use strict";
 
+const RuleTester = require("./rule-tester");
+
 module.exports = {
-    RuleTester: require("./rule-tester")
+    RuleTester
 };

lib/rules/utils/lazy-loading-rule-map.js

@@ -6,7 +6,7 @@
 
 const debug = require("debug")("eslint:rules");
 
-/** @typedef {import("./types").Rule} Rule */
+/** @typedef {import("../../shared/types").Rule} Rule */
 
 /**
  * The `Map` object that loads each rule when it's accessed.

lib/rules/utils/unicode/index.js

@@ -3,9 +3,14 @@
  */
 "use strict";
 
+const isCombiningCharacter = require("./is-combining-character");
+const isEmojiModifier = require("./is-emoji-modifier");
+const isRegionalIndicatorSymbol = require("./is-regional-indicator-symbol");
+const isSurrogatePair = require("./is-surrogate-pair");
+
 module.exports = {
-    isCombiningCharacter: require("./is-combining-character"),
-    isEmojiModifier: require("./is-emoji-modifier"),
-    isRegionalIndicatorSymbol: require("./is-regional-indicator-symbol"),
-    isSurrogatePair: require("./is-surrogate-pair")
+    isCombiningCharacter,
+    isEmojiModifier,
+    isRegionalIndicatorSymbol,
+    isSurrogatePair
 };