Switch from eslint to oxlint

.eslintrc.cjs

@@ -1,120 +0,0 @@
-const COPYRIGHT_HEADER = `/*
-Copyright %%CURRENT_YEAR%% New Vector Ltd.
-
-SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
-Please see LICENSE in the repository root for full details.
-*/
-
-`;
-
-module.exports = {
-  plugins: ["matrix-org", "rxjs", "jsdoc", "element-call"],
-  extends: [
-    "plugin:matrix-org/react",
-    "plugin:matrix-org/a11y",
-    "plugin:matrix-org/typescript",
-    "prettier",
-    "plugin:rxjs/recommended",
-    "plugin:storybook/recommended",
-  ],
-  parserOptions: {
-    ecmaVersion: "latest",
-    sourceType: "module",
-    project: ["./tsconfig.json"],
-  },
-  env: {
-    browser: true,
-    node: true,
-  },
-  rules: {
-    "element-call/no-observablescope-leak": "error",
-    "jsdoc/no-types": "error",
-    "jsdoc/empty-tags": "error",
-    "jsdoc/check-property-names": "error",
-    "jsdoc/check-values": "error",
-    "jsdoc/check-param-names": "warn",
-    // "jsdoc/require-param": "warn",
-    "jsdoc/require-param-description": "warn",
-    "matrix-org/require-copyright-header": ["error", COPYRIGHT_HEADER],
-    "jsx-a11y/media-has-caption": "off",
-    "react/display-name": "error",
-    // Encourage proper usage of Promises:
-    "@typescript-eslint/no-floating-promises": "error",
-    "@typescript-eslint/no-misused-promises": "error",
-    "@typescript-eslint/promise-function-async": "error",
-    "@typescript-eslint/require-await": "error",
-    "@typescript-eslint/await-thenable": "error",
-    // To help ensure that we get proper vite/rollup lazy loading (e.g. for matrix-js-sdk):
-    "@typescript-eslint/consistent-type-imports": [
-      "error",
-      { fixStyle: "inline-type-imports" },
-    ],
-    // To encourage good usage of RxJS:
-    "rxjs/no-exposed-subjects": "error",
-    "rxjs/finnish": ["error", { names: { "^this$": false } }],
-    "no-restricted-imports": [
-      "error",
-      {
-        paths: ["matrix-widget-api", "matrix-js-sdk"].flatMap((lib) =>
-          ["src", "src/", "src/index", "lib", "lib/", "lib/index"]
-            .map((path) => `${lib}/${path}`)
-            .map((name) => ({ name, message: `Please use ${lib} instead` })),
-        ),
-        patterns: [
-          ...["matrix-widget-api"].map((lib) => ({
-            group: ["src", "src/", "src/**", "lib", "lib/", "lib/**"].map(
-              (path) => `${lib}/${path}`,
-            ),
-            message: `Please use ${lib} instead`,
-          })),
-          // XXX: We use /lib in lots of places, so allow for now.
-          ...["matrix-js-sdk"].map((lib) => ({
-            group: ["src", "src/", "src/**"].map((path) => `${lib}/${path}`),
-            message: `Please use ${lib} instead`,
-          })),
-        ],
-      },
-    ],
-  },
-  overrides: [
-    {
-      files: ["src/*/**"],
-      rules: {
-        // In application code we should use the js-sdk logger, never console directly.
-        "no-console": ["error"],
-      },
-    },
-    {
-      files: [
-        "**/*.test.ts",
-        "**/*.test.tsx",
-        "**/test.ts",
-        "**/test.tsx",
-        "**/test-**",
-      ],
-      rules: {
-        // Tests often initialize an ObservableScope in an outer scope in
-        // beforeEach, which is not actually a problem
-        "element-call/no-observablescope-leak": "off",
-        "jsdoc/no-types": "off",
-        "jsdoc/empty-tags": "off",
-        "jsdoc/check-property-names": "off",
-        "jsdoc/check-values": "off",
-        "jsdoc/check-param-names": "off",
-        "jsdoc/require-param-description": "off",
-      },
-    },
-    {
-      files: ["playwright/**"],
-      rules: {
-        // Playwright as a `use` function that has nothing to do with React hooks.
-        "react-hooks/rules-of-hooks": "off",
-      },
-    },
-  ],
-  settings: {
-    react: {
-      version: "detect",
-    },
-  },
-};

.github/workflows/lint.yaml

@@ -24,8 +24,8 @@ jobs:
         run: "pnpm run format:check"
       - name: i18n
         run: "pnpm run i18n:check"
-      - name: ESLint
+      - name: Lint
-        run: "pnpm run lint:eslint"
+        run: "pnpm run lint:oxlint"
       - name: Type check
         run: "pnpm run lint:types"
       - name: Dead code analysis

.oxlintrc.json

@@ -0,0 +1,197 @@
+{
+  "$schema": "./node_modules/oxlint/configuration_schema.json",
+  "plugins": [
+    "eslint",
+    "import",
+    "jsdoc",
+    "jsx-a11y",
+    "promise",
+    "react",
+    "typescript",
+    "unicorn",
+    "vitest"
+  ],
+  "jsPlugins": [
+    "eslint-plugin-storybook",
+    "eslint-plugin-element-call"
+    // TODO: Re-enable once oxlint supports lint rules that rely on TypeScript type-awareness.
+    // "eslint-plugin-rxjs"
+  ],
+  "categories": {
+    "correctness": "error",
+    "perf": "error"
+  },
+  "options": {
+    "denyWarnings": true,
+    "typeAware": true
+  },
+  "env": {
+    "builtin": true
+  },
+  "rules": {
+    "element-call/no-observablescope-leak": "error",
+    "jsdoc/empty-tags": "error",
+    "jsdoc/check-property-names": "error",
+    "jsdoc/require-param-description": "warn",
+    "react/display-name": "error",
+    // TODO: Re-enable once oxlint supports lint rules that rely on TypeScript type-awareness.
+    // "rxjs/no-exposed-subjects": "error",
+    // "rxjs/finnish": [
+    //   "error",
+    //   {
+    //     "names": {
+    //       "^this$": false
+    //     }
+    //   }
+    // ],
+    "no-restricted-imports": [
+      "error",
+      {
+        "paths": [
+          {
+            "name": "matrix-widget-api/src",
+            "message": "Please use matrix-widget-api instead"
+          },
+          {
+            "name": "matrix-widget-api/src/",
+            "message": "Please use matrix-widget-api instead"
+          },
+          {
+            "name": "matrix-widget-api/src/index",
+            "message": "Please use matrix-widget-api instead"
+          },
+          {
+            "name": "matrix-widget-api/lib",
+            "message": "Please use matrix-widget-api instead"
+          },
+          {
+            "name": "matrix-widget-api/lib/",
+            "message": "Please use matrix-widget-api instead"
+          },
+          {
+            "name": "matrix-widget-api/lib/index",
+            "message": "Please use matrix-widget-api instead"
+          },
+          {
+            "name": "matrix-js-sdk/src",
+            "message": "Please use matrix-js-sdk instead"
+          },
+          {
+            "name": "matrix-js-sdk/src/",
+            "message": "Please use matrix-js-sdk instead"
+          },
+          {
+            "name": "matrix-js-sdk/src/index",
+            "message": "Please use matrix-js-sdk instead"
+          },
+          {
+            "name": "matrix-js-sdk/lib",
+            "message": "Please use matrix-js-sdk instead"
+          },
+          {
+            "name": "matrix-js-sdk/lib/",
+            "message": "Please use matrix-js-sdk instead"
+          },
+          {
+            "name": "matrix-js-sdk/lib/index",
+            "message": "Please use matrix-js-sdk instead"
+          }
+        ],
+        "patterns": [
+          {
+            "group": [
+              "matrix-widget-api/src",
+              "matrix-widget-api/src/",
+              "matrix-widget-api/src/**",
+              "matrix-widget-api/lib",
+              "matrix-widget-api/lib/",
+              "matrix-widget-api/lib/**"
+            ],
+            "message": "Please use matrix-widget-api instead"
+          },
+          {
+            "group": [
+              // We use /lib in lots of places, so allow for now.
+              "matrix-js-sdk/src",
+              "matrix-js-sdk/src/",
+              "matrix-js-sdk/src/**"
+            ],
+            "message": "Please use matrix-js-sdk instead"
+          }
+        ]
+      }
+    ],
+    "typescript/no-floating-promises": "error",
+    "typescript/no-misused-promises": "error",
+    "typescript/promise-function-async": "error",
+    "typescript/require-await": "error",
+    "typescript/await-thenable": "error",
+    // To help ensure that we get proper vite/rollup lazy loading (e.g. for matrix-js-sdk).
+    "typescript/consistent-type-imports": [
+      "error",
+      {
+        "fixStyle": "inline-type-imports"
+      }
+    ],
+    // TODO: These had to be disabled in the eslint -> oxlint migration. Would be nice to
+    // enable them in future or at least document why we're disabling them.
+    "eslint/no-await-in-loop": "off",
+    "eslint/no-unused-vars": ["error", { "args": "none" }],
+    "import/default": "off",
+    "jsdoc/check-tag-names": "off",
+    "jsx-a11y/prefer-tag-over-role": "off",
+    "promise/no-callback-in-promise": "off",
+    "react/jsx-key": "off",
+    "react/jsx-no-constructed-context-values": "off",
+    "react/no-array-index-key": "off",
+    "react/no-children-prop": "off",
+    "react/no-object-type-as-default-prop": "off",
+    "typescript/no-misused-spread": "off",
+    "typescript/no-useless-default-assignment": "off",
+    "typescript/restrict-template-expressions": "off",
+    "typescript/unbound-method": "off",
+    "vitest/expect-expect": "off",
+    "vitest/no-conditional-expect": "off",
+    "vitest/no-disabled-tests": "off",
+    "vitest/require-mock-type-parameters": "off",
+    "vitest/require-to-throw-message": "off"
+  },
+  "overrides": [
+    {
+      "files": ["src/*/**"],
+      "rules": {
+        // In application code we should use the js-sdk logger, never console directly.
+        "no-console": "error"
+      }
+    },
+    {
+      "files": [
+        "**/*.test.ts",
+        "**/*.test.tsx",
+        "**/test.ts",
+        "**/test.tsx",
+        "**/test-**"
+      ],
+      "rules": {
+        // Tests often initialize an ObservableScope in an outer scope in
+        // beforeEach, which is not actually a problem
+        "element-call/no-observablescope-leak": "off",
+        "jsdoc/empty-tags": "off",
+        "jsdoc/check-property-names": "off",
+        "jsdoc/require-param-description": "off",
+        "jsx-a11y/media-has-caption": "off"
+        // TODO: Enable once oxlint supports them.
+        // "jsdoc/check-values": "off",
+        // "jsdoc/check-param-names": "off",
+        // "jsdoc/no-types": "off",
+      }
+    },
+    {
+      "files": ["playwright/**"],
+      "rules": {
+        // Playwright as a `use` function that has nothing to do with React hooks.
+        "react-hooks/rules-of-hooks": "off"
+      }
+    }
+  ]
+}

eslint/NoObservableScopeLeak.js

@@ -40,19 +40,23 @@ const rule = ESLintUtils.RuleCreator(
           node.parent?.type === "MemberExpression" &&
           node.parent.object === node &&
           node.parent.property.type === "Identifier" &&
-          !safeScopeMethods.includes(node.parent.property.name)
+          !safeScopeMethods.includes(node.parent.property.name) &&
+          node.name.endsWith("cope")
         ) {
-          // Verify that the variable is actually of type ObservableScope
+          // TODO: Once oxlint supports lint rules that rely on TypeScript type-awareness,
-          // (expensive, so we check this last)
+          // Verify that the variable is actually of type ObservableScope rather than just
-          const services = ESLintUtils.getParserServices(context);
+          // checking its name. This is expensive so we should do this last.
-          const type = services.getTypeAtLocation(node);
+          //
-          if (type.symbol?.name === "ObservableScope")
+          // const services = ESLintUtils.getParserServices(context);
-            // This ObservableScope method call may be causing resource leaks.
+          // const type = services.getTypeAtLocation(node);
-            context.report({
+          // if (type.symbol?.name === "ObservableScope") { ... }
-              messageId: "scopeLeak",
+
-              loc: node.loc,
+          // This ObservableScope method call may be causing resource leaks.
-              node,
+          context.report({
-            });
+            messageId: "scopeLeak",
+            loc: node.loc,
+            node,
+          });
         }
       },
     };

knip.ts

@@ -32,6 +32,9 @@ export default {
     // https://github.com/webpro-nl/knip/issues/766
     "@vector-im/compound-web",
     "matrix-widget-api",
+    // Used by oxlint
+    "eslint-plugin-element-call",
+    "eslint-plugin-storybook",
   ],
   ignoreExportsUsedInFile: true,
 } satisfies KnipConfig;

package.json

@@ -19,9 +19,9 @@
     "serve": "vite preview",
     "format": "oxfmt",
     "format:check": "oxfmt --check; rc=$?; [[ $rc -ne 0 ]] && printf '\\033[46;30m INFO \\033[0m To fix, run: pnpm format\\n' >&2; exit $rc",
-    "lint": "pnpm lint:types && pnpm lint:eslint && pnpm lint:knip",
+    "lint": "pnpm lint:types && pnpm lint:oxlint && pnpm lint:knip",
-    "lint:eslint": "eslint --max-warnings 0 src playwright",
+    "lint:oxlint": "oxlint src playwright",
-    "lint:eslint-fix": "eslint --max-warnings 0 src playwright --fix",
+    "lint:oxlint-fix": "oxlint --fix src playwright",
     "lint:knip": "knip",
     "lint:types": "tsc",
     "i18n": "npx i18next-cli extract",
@@ -60,7 +60,6 @@
     "@storybook/addon-docs": "^10.3.6",
     "@storybook/addon-vitest": "^10.3.6",
     "@storybook/react-vite": "^10.3.6",
-    "@stylistic/eslint-plugin": "^3.0.0",
     "@testing-library/dom": "^10.1.0",
     "@testing-library/jest-dom": "^6.6.3",
     "@testing-library/react": "^16.0.0",
@@ -75,8 +74,6 @@
     "@types/react": "^19.0.0",
     "@types/react-dom": "^19.0.0",
     "@types/sdp-transform": "^2.4.5",
-    "@typescript-eslint/eslint-plugin": "^8.31.0",
-    "@typescript-eslint/parser": "^8.31.0",
     "@typescript-eslint/utils": "^8.61.0",
     "@use-gesture/react": "^10.2.11",
     "@vector-im/compound-design-tokens": "^10.0.0",
@@ -87,20 +84,8 @@
     "@vitest/ui": "4.1.7",
     "classnames": "^2.3.1",
     "copy-to-clipboard": "^3.3.3",
-    "eslint": "^8.14.0",
-    "eslint-config-google": "^0.14.0",
-    "eslint-config-prettier": "^10.0.0",
-    "eslint-plugin-deprecate": "^0.9.0",
     "eslint-plugin-element-call": "link:eslint",
-    "eslint-plugin-import": "^2.26.0",
-    "eslint-plugin-jsdoc": "^61.5.0",
-    "eslint-plugin-jsx-a11y": "^6.5.1",
-    "eslint-plugin-matrix-org": "2.1.0",
-    "eslint-plugin-react": "^7.29.4",
-    "eslint-plugin-react-hooks": "^5.0.0",
-    "eslint-plugin-rxjs": "^5.0.3",
     "eslint-plugin-storybook": "^10.3.6",
-    "eslint-plugin-unicorn": "^56.0.0",
     "fetch-mock": "11.1.5",
     "global-jsdom": "^26.0.0",
     "i18next": "^25.0.0",
@@ -117,6 +102,8 @@
     "normalize.css": "^8.0.1",
     "observable-hooks": "^4.2.3",
     "oxfmt": "^0.55.0",
+    "oxlint": "^1.70.0",
+    "oxlint-tsgolint": "^0.23.0",
     "pako": "^2.0.4",
     "postcss": "^8.4.41",
     "postcss-preset-env": "^10.0.0",
@@ -131,7 +118,6 @@
     "sass": "^1.42.1",
     "storybook": "^10.3.6",
     "typescript": "^5.8.3",
-    "typescript-eslint-language-service": "^5.0.5",
     "unique-names-generator": "^4.6.0",
     "uuid": "^14.0.0",
     "vaul": "^1.0.0",

renovate.json

@@ -64,7 +64,7 @@
     }
   ],
   "semanticCommits": "disabled",
-  "ignoreDeps": ["eslint-plugin-matrix-org"],
+  "ignoreDeps": [],
   "vulnerabilityAlerts": {
     "schedule": ["at any time"],
     "prHourlyLimit": 0,

src/FullScreenView.tsx

@@ -47,7 +47,7 @@ export const FullScreenView: FC<FullScreenViewProps> = ({
 };
 
 interface ErrorPageProps {
-  error: Error | unknown;
+  error: unknown;
   widget: WidgetHelpers | null;
 }
 

src/state/AndroidControlledAudioOutput.test.ts

@@ -253,7 +253,7 @@ describe("Test mappings", () => {
 });
 
 describe("Test select a device", () => {
-  it(`Switch to correct device `, () => {
+  it(`Switch to correct device`, () => {
     withTestScheduler(({ cold, schedule, expectObservable, flush }) => {
       const controlledAudioOutput = new AndroidControlledAudioOutput(
         cold("a", { a: FULL_DEVICE_LIST }),

src/state/CallViewModel/localMember/LocalMember.ts

@@ -170,7 +170,7 @@ export const createLocalMembership$ = ({
   logger: parentLogger,
   muteStates,
   matrixRTCSession,
-  roomId: roomId,
+  roomId,
 }: Props): {
   /**
    * This request to start audio and video tracks.

src/state/CallViewModel/localMember/RtcTransportAutoDiscovery.ts

@@ -102,7 +102,7 @@ export class RtcTransportAutoDiscovery {
         const transportList = await doNetworkOperationWithRetry(async () =>
           client._unstable_getRTCTransports(),
         );
-        const first = transportList.filter(isLivekitTransportConfig)[0];
+        const first = transportList.find(isLivekitTransportConfig);
         if (first) {
           return first;
         } else {

src/state/TileStore.ts

@@ -131,9 +131,9 @@ export class TileStoreBuilder {
   private numGridEntries = 0;
   // A sparse array of grid entries which should be kept in the same spots as
   // which they appeared in the previous grid
-  private readonly stationaryGridEntries: GridTileData[] = new Array(
+  private readonly stationaryGridEntries: GridTileData[] = Array.from({
-    this.prevGrid.length,
+    length: this.prevGrid.length,
-  );
+  });
   // Grid entries which should now enter the visible section of the grid
   private readonly visibleGridEntries: GridTileData[] = [];
   // Grid entries which should now enter the invisible section of the grid

src/utils/test-viewmodel.ts

@@ -128,8 +128,8 @@ export function getBasicRTCSession(
 
 /**
  * Construct a basic CallViewModel to test components that make use of it.
- * @param members
+ * @param members - Room members to include in the call.
- * @param initialRtcMemberships
+ * @param initialRtcMemberships - RTC memberships to start with.
  * @returns
  */
 export function getBasicCallViewModelEnvironment(

tsconfig.json

@@ -38,7 +38,7 @@
       "livekit-client/dist/src/proto/livekit_models_pb": [
         "./node_modules/@livekit/protocol/src/gen/livekit_models_pb.d.ts"
       ]
-    },
+    }
 
     // TODO: Enable the following options later.
     // "forceConsistentCasingInFileNames": true,
@@ -48,8 +48,6 @@
     // "noPropertyAccessFromIndexSignature": true,
     // "noUncheckedIndexedAccess": true,
     // "noUnusedParameters": true,
-
-    "plugins": [{ "name": "typescript-eslint-language-service" }]
   },
   "include": [
     "./src/**/*.ts",