update eslint to v9

BUILD.bazel

@@ -1,3 +1,4 @@
+load("@aspect_rules_js//js:defs.bzl", "js_library")
 load("@aspect_rules_js//npm:defs.bzl", "npm_link_package")
 load("@bazel_skylib//lib:selects.bzl", "selects")
 load("@bazel_skylib//rules:common_settings.bzl", "bool_flag")
@@ -89,3 +90,10 @@ selects.config_setting_group(
         ":not_dbg_build",
     ],
 )
+
+# prettier
+js_library(
+    name = "prettierrc",
+    srcs = [".prettierrc.json"],
+    visibility = ["//visibility:public"],
+)

build/wd_ts_bundle.bzl

@@ -90,7 +90,8 @@ def wd_ts_bundle_capnp(
             data = srcs + [
                 eslintrc_json,
                 tsconfig_json,
-                "//:node_modules/@typescript-eslint/eslint-plugin",
+                "//tools:base-eslint",
+                "//:prettierrc",
             ],
             tags = ["lint"],
             target_compatible_with = select({

package.json

@@ -7,24 +7,23 @@
   },
   "dependencies": {
     "capnp-ts": "^0.7.0",
-    "prettier": "^3.2.5",
+    "prettier": "^3.3.3",
     "typescript": "5.5.4"
   },
   "devDependencies": {
     "@bazel/bazelisk": "~1.19.0",
+    "@eslint/js": "^9.9.0",
     "@types/debug": "^4.1.10",
+    "@types/eslint__js": "^8.42.3",
     "@types/node": "^20.14.8",
-    "@types/prettier": "^2.7.1",
-    "@typescript-eslint/eslint-plugin": "^7.3.1",
-    "@typescript-eslint/parser": "^7.3.1",
     "capnpc-ts": "^0.7.0",
     "chrome-remote-interface": "^0.33.2",
     "esbuild": "^0.15.18",
-    "eslint": "^8.57.0",
-    "eslint-config-prettier": "^9.1.0",
+    "eslint": "^9.9.0",
     "eslint-plugin-import": "^2.29.1",
-    "eslint-plugin-prettier": "^5.1.3",
-    "expect-type": "^0.18.0"
+    "eslint-plugin-prettier": "^5.2.1",
+    "expect-type": "^0.18.0",
+    "typescript-eslint": "^8.2.0"
   },
   "pnpm": {
     "overrides": {

src/cloudflare/BUILD.bazel

@@ -2,7 +2,7 @@ load("@workerd//:build/wd_ts_bundle.bzl", "wd_ts_bundle")
 
 wd_ts_bundle(
     name = "cloudflare",
-    eslintrc_json = ".eslintrc.json",
+    eslintrc_json = "eslint.config.mjs",
     import_name = "cloudflare",
     internal_modules = glob(
         [

src/cloudflare/eslint.config.mjs

@@ -0,0 +1,4 @@
+import { baseConfig } from '../../tools/base.eslint.config.mjs';
+
+// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+export default [...baseConfig({ tsconfigRootDir: import.meta.dirname })];

src/node/BUILD.bazel

@@ -2,7 +2,7 @@ load("@workerd//:build/wd_ts_bundle.bzl", "wd_ts_bundle")
 
 wd_ts_bundle(
     name = "node",
-    eslintrc_json = ".eslintrc.json",
+    eslintrc_json = "eslint.config.mjs",
     import_name = "node",
     internal_modules = glob([
         "internal/*.ts",

src/node/eslint.config.mjs

@@ -0,0 +1,3 @@
+import { baseConfig } from '../../tools/base.eslint.config.mjs';
+
+export default [...baseConfig({ tsconfigRootDir: import.meta.dirname })];

src/pyodide/BUILD.bazel

@@ -147,7 +147,7 @@ expand_template(
 
 data = wd_ts_bundle_capnp(
     name = "pyodide.capnp",
-    eslintrc_json = ".eslintrc.json",
+    eslintrc_json = "eslint.config.mjs",
     import_name = "pyodide",
     internal_data_modules = ["generated/python_stdlib.zip"] + glob([
         "internal/*.py",
@@ -181,6 +181,7 @@ data = wd_ts_bundle_capnp(
     ],
     lint = False,
     modules = ["python-entrypoint-helper.ts"],
+    modules = ["python-entrypoint-helper.ts"],
     schema_id = "0xbcc8f57c63814005",
     tsconfig_json = "tsconfig.json",
 )

tools/BUILD.bazel

@@ -0,0 +1,12 @@
+load("@aspect_rules_js//js:defs.bzl", "js_library")
+
+js_library(
+    name = "base-eslint",
+    srcs = ["base.eslint.config.mjs"],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//:node_modules/@eslint/js",
+        "//:node_modules/eslint-plugin-prettier",
+        "//:node_modules/typescript-eslint",
+    ],
+)

tools/base.eslint.config.mjs

@@ -0,0 +1,49 @@
+import eslint from "@eslint/js";
+import tseslint from "typescript-eslint";
+import prettierPlugin from "eslint-plugin-prettier/recommended";
+
+/**
+ * @param {string} tsconfigRootDir
+ * @returns {FlatConfig.ConfigArray}
+ */
+export function baseConfig({ tsconfigRootDir }) {
+  return tseslint.config(
+    eslint.configs.recommended,
+    ...tseslint.configs.strictTypeChecked,
+    {
+      languageOptions: {
+        parserOptions: {
+          ecmaVersion: "latest",
+          sourceType: "module",
+          projectService: true,
+          tsconfigRootDir,
+        },
+      },
+      rules: {
+        "@typescript-eslint/explicit-function-return-type": "error",
+        "@typescript-eslint/explicit-member-accessibility": "error",
+        "@typescript-eslint/explicit-module-boundary-types": "error",
+        "@typescript-eslint/no-require-imports": "error",
+        "@typescript-eslint/prefer-enum-initializers": "error",
+        "@typescript-eslint/type-annotation-spacing": "error",
+        "@typescript-eslint/restrict-template-expressions": "warn",
+        "@typescript-eslint/no-non-null-assertion": "warn",
+        "@typescript-eslint/no-extraneous-class": "off",
+        "@typescript-eslint/unified-signatures": "off",
+        "@typescript-eslint/no-unused-vars": [
+          "error",
+          {
+            args: "all",
+            argsIgnorePattern: "^_",
+            caughtErrors: "all",
+            caughtErrorsIgnorePattern: "^_",
+            destructuredArrayIgnorePattern: "^_",
+            varsIgnorePattern: "^_",
+            ignoreRestSiblings: true,
+          },
+        ],
+      },
+    },
+    prettierPlugin,
+  )
+}

types/eslint.config.mjs

@@ -0,0 +1,38 @@
+import eslint from "@eslint/js";
+import importPlugin from "eslint-plugin-import";
+import prettierPlugin from "eslint-plugin-prettier/recommended";
+import tseslint from "typescript-eslint";
+
+export default tseslint.config(
+  eslint.configs.recommended,
+  ...tseslint.configs.strictTypeChecked,
+  {
+    languageOptions: {
+      parserOptions: {
+        ecmaVersion: "latest",
+        sourceType: "module",
+        projectService: true,
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
+    rules: {
+      "@typescript-eslint/ban-ts-comment": "off",
+      "@typescript-eslint/no-non-null-assertion": "off",
+      "@typescript-eslint/no-explicit-any": "off",
+      "@typescript-eslint/no-empty-function": "off",
+      "@typescript-eslint/no-unused-vars": [
+        "warn",
+        { argsIgnorePattern: "^_" },
+      ],
+    },
+  },
+  {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+    plugins: { import: importPlugin },
+    rules: {
+      "import/order": ["warn", { alphabetize: { order: "asc" } }],
+      "sort-imports": ["warn", { ignoreDeclarationSort: true }],
+    },
+  },
+  prettierPlugin
+);

types/tsconfig.json

@@ -19,6 +19,6 @@
     "composite": true,
     "skipLibCheck": true
   },
-  "include": ["src/**/*.ts", "test/**/*.ts", "scripts/**/*.ts"],
+  "include": ["src/**/*.ts", "test/**/*.ts", "scripts/**/*.ts", "eslint.config.mjs"],
   "exclude": ["test/types/**/*.ts", "src/worker/**"]
 }