chore: Migrate to ESLint v9

.depcheckrc.yaml

@@ -1,6 +1,7 @@
 ignores:
   - "@tsconfig/node18"
   - "@tsconfig/strictest"
+  - "@types/eslint__js"
   - "@types/node"
   - prettier-plugin-pkg
   - ts-proto

.github/renovate.json

@@ -51,18 +51,6 @@
       "matchPackageNames": ["@types/node"],
       "matchUpdateTypes": ["major"],
       "enabled": false
-    },
-    {
-      "description": "eslint v9 is not widely supported by plugins yet",
-      "matchPackageNames": ["eslint"],
-      "matchUpdateTypes": ["major"],
-      "enabled": false
-    },
-    {
-      "description": "eslint-plugin-vitest only supports flat config from v0.5.0 (https://github.com/veritem/eslint-plugin-vitest/issues/414)",
-      "matchPackageNames": ["eslint-plugin-vitest"],
-      "matchUpdateTypes": ["minor"],
-      "enabled": false
     }
   ],
   "postUpdateOptions": ["pnpmDedupe"],

eslint.config.mjs

@@ -0,0 +1,137 @@
+import eslint from "@eslint/js";
+import vitestPlugin from "@vitest/eslint-plugin";
+import importPlugin from "eslint-plugin-import";
+import reactHooksPlugin from "eslint-plugin-react-hooks";
+import tsdocPlugin from "eslint-plugin-tsdoc";
+import typescriptPlugin from "typescript-eslint";
+
+export default typescriptPlugin.config(
+  {
+    ignores: [
+      "packages/*/lib/**",
+      "packages/*/src/protobuf/**",
+      "private/*/src/protobuf/**",
+    ],
+  },
+  eslint.configs.recommended,
+  ...typescriptPlugin.configs.strictTypeChecked,
+  ...typescriptPlugin.configs.stylisticTypeChecked,
+  importPlugin.flatConfigs.typescript,
+  {
+    plugins: {
+      import: importPlugin,
+    },
+    settings: {
+      "import/internal-regex": "^@cerbos/",
+    },
+    languageOptions: {
+      parserOptions: {
+        projectService: true,
+      },
+    },
+    rules: {
+      "@typescript-eslint/consistent-type-imports": "warn",
+      "@typescript-eslint/explicit-function-return-type": "warn",
+      "@typescript-eslint/explicit-member-accessibility": "warn",
+      "@typescript-eslint/no-confusing-void-expression": "warn",
+      "@typescript-eslint/no-require-imports": [
+        "warn",
+        { allow: ["/package\\.json$"] },
+      ],
+      "@typescript-eslint/no-unnecessary-condition": [
+        "warn",
+        { allowConstantLoopConditions: true },
+      ],
+      "@typescript-eslint/no-unused-vars": [
+        "warn",
+        {
+          argsIgnorePattern: "^_",
+          ignoreRestSiblings: true,
+        },
+      ],
+      "@typescript-eslint/prefer-enum-initializers": "warn",
+      "@typescript-eslint/prefer-nullish-coalescing": "warn",
+      "@typescript-eslint/promise-function-async": "warn",
+      "@typescript-eslint/restrict-template-expressions": [
+        "warn",
+        { allowNumber: true },
+      ],
+      "@typescript-eslint/return-await": ["warn", "always"],
+      curly: "warn",
+      "func-style": ["warn", "declaration"],
+      "import/consistent-type-specifier-style": ["warn", "prefer-top-level"],
+      "import/export": "warn",
+      "import/newline-after-import": "warn",
+      "import/no-duplicates": "warn",
+      "import/no-extraneous-dependencies": [
+        "warn",
+        {
+          devDependencies: ["private/**", "eslint.config.mjs"],
+          optionalDependencies: false,
+          includeTypes: true,
+        },
+      ],
+      "import/no-named-as-default": "warn",
+      "import/order": [
+        "warn",
+        {
+          alphabetize: {
+            order: "asc",
+            orderImportKind: "asc",
+            caseInsensitive: true,
+          },
+          groups: [
+            "builtin",
+            "external",
+            "internal",
+            "parent",
+            "sibling",
+            "index",
+          ],
+          "newlines-between": "always",
+        },
+      ],
+      "no-console": "warn",
+      "no-constant-condition": ["warn", { checkLoops: false }],
+      quotes: ["warn", "double", { avoidEscape: true }],
+      "sort-imports": ["warn", { ignoreDeclarationSort: true }],
+    },
+  },
+  {
+    files: ["**/*.ts"],
+    plugins: {
+      tsdoc: tsdocPlugin,
+    },
+    rules: {
+      "tsdoc/syntax": "warn",
+    },
+  },
+  {
+    files: ["packages/react/**"],
+    plugins: {
+      "react-hooks": reactHooksPlugin,
+    },
+    rules: reactHooksPlugin.configs.recommended.rules,
+  },
+  {
+    files: ["private/scripts/**"],
+    rules: {
+      "no-console": "off",
+    },
+  },
+  {
+    files: ["**/*.test.ts", "private/test/src/helpers.ts"],
+    ...vitestPlugin.configs.recommended,
+    settings: {
+      vitest: {
+        typecheck: true,
+      },
+    },
+    rules: {
+      "@typescript-eslint/no-unsafe-assignment": "off",
+      "@typescript-eslint/no-unsafe-member-access": "off",
+      "@typescript-eslint/no-unsafe-argument": "off",
+      "vitest/expect-expect": ["warn", { assertFunctionNames: ["expect*"] }],
+    },
+  },
+);

package.json

@@ -51,22 +51,25 @@
   },
   "devDependencies": {
     "@arethetypeswrong/cli": "0.16.4",
+    "@eslint/js": "9.12.0",
     "@microsoft/api-documenter": "7.25.17",
     "@microsoft/api-extractor": "7.47.9",
     "@tsconfig/node18": "18.2.4",
     "@tsconfig/strictest": "2.0.5",
+    "@types/eslint__js": "8.42.3",
     "@types/node": "18.19.55",
-    "@typescript-eslint/eslint-plugin": "8.8.1",
-    "@typescript-eslint/parser": "8.8.1",
+    "@vitest/eslint-plugin": "1.1.7",
     "concurrently": "9.0.1",
     "depcheck": "1.4.7",
-    "eslint": "8.57.1",
+    "eslint": "9.12.0",
     "eslint-plugin-import": "2.31.0",
+    "eslint-plugin-react-hooks": "5.0.0",
     "eslint-plugin-tsdoc": "0.3.0",
     "prettier": "3.3.3",
     "prettier-plugin-pkg": "0.18.1",
     "ts-proto": "2.2.3",
     "tsx": "4.19.1",
-    "typescript": "5.6.3"
+    "typescript": "5.6.3",
+    "typescript-eslint": "8.8.1"
   }
 }

packages/grpc/src/client.ts

@@ -7,7 +7,6 @@ import { Client } from "@cerbos/core";
 
 import { Transport } from "./transport";
 
-// eslint-disable-next-line @typescript-eslint/no-var-requires -- Can't import package.json because it is outside of the project's rootDir
 const { version } = require("../package.json") as { version: string };
 
 const defaultUserAgent = `cerbos-sdk-javascript-grpc/${version}`;

packages/http/src/client.ts

@@ -3,7 +3,6 @@ import { Client } from "@cerbos/core";
 
 import { Transport } from "./transport";
 
-// eslint-disable-next-line @typescript-eslint/no-var-requires -- Can't import package.json because it is outside of the project's rootDir
 const { version } = require("../package.json") as { version: string };
 
 const defaultUserAgent = `cerbos-sdk-javascript-http/${version}`;

packages/opentelemetry/src/metadata.ts

@@ -1,4 +1,3 @@
-// eslint-disable-next-line @typescript-eslint/no-var-requires -- Can't import package.json because it is outside of the project's rootDir
 export const { name, version } = require("../package.json") as {
   name: string;
   version: string;

packages/react/package.json

@@ -56,8 +56,7 @@
     "use-deep-compare-effect": "^1.8.1"
   },
   "devDependencies": {
-    "@types/react": "18.3.11",
-    "eslint-plugin-react-hooks": "4.6.2"
+    "@types/react": "18.3.11"
   },
   "publishConfig": {
     "access": "public",