Upgrade to eslint 9

Author: robertbrignull

.eslintignore

@@ -1,6 +1,7 @@
 import { rm } from "node:fs/promises";
 import { dirname, join } from "node:path";
 import { fileURLToPath } from "node:url";
+
 import * as esbuild from "esbuild";
 
 const __filename = fileURLToPath(import.meta.url);
@@ -31,7 +32,7 @@ const context = await esbuild.context({
   outdir: "dist",
   platform: "node",
   format: "cjs",
-  sourcemap: !!process.env.CODEQL_VARIANT_ANALYSIS_ACTION_GENERATE_SOURCEMAPS
+  sourcemap: process.env.CODEQL_VARIANT_ANALYSIS_ACTION_GENERATE_SOURCEMAPS
     ? "external"
     : false,
   chunkNames: "chunks/[name]-[hash]",

.eslintrc.json

@@ -0,0 +1,82 @@
+import path from "path";
+import { fileURLToPath } from "url";
+
+import { FlatCompat } from "@eslint/eslintrc";
+import eslint from "@eslint/js";
+import { globalIgnores } from "eslint/config";
+import github from "eslint-plugin-github";
+import tseslint from "typescript-eslint";
+
+const compat = new FlatCompat({
+  baseDirectory: path.dirname(fileURLToPath(import.meta.url)),
+});
+
+export default tseslint.config(
+  globalIgnores(["dist/", "node_modules/", "jest.config.ts", "eslint.config.mjs", "build.mjs"]),
+  ...compat.plugins("no-async-foreach"),
+  github.getFlatConfigs().recommended,
+  ...github.getFlatConfigs().typescript,
+  {
+    extends: [eslint.configs.recommended, tseslint.configs.recommended],
+  },
+  {
+    rules: {
+      "sort-imports": "off",
+      "i18n-text/no-en": "off",
+      "import/extensions": [
+        "error",
+        {
+          json: "always",
+        },
+      ],
+      "import/named": "off",
+      "import/no-amd": "error",
+      "import/no-commonjs": "error",
+      "import/no-dynamic-require": "error",
+      "import/no-extraneous-dependencies": [
+        "error",
+        {
+          devDependencies: true,
+        },
+      ],
+      "import/no-namespace": "off",
+      "import/no-unresolved": "error",
+      "import/no-webpack-loader-syntax": "error",
+      "import/order": [
+        "error",
+        {
+          alphabetize: {
+            order: "asc",
+          },
+          "newlines-between": "always",
+        },
+      ],
+      "no-async-foreach/no-async-foreach": "error",
+      "no-console": "off",
+      "no-sequences": "error",
+      "no-shadow": "off",
+      "@typescript-eslint/naming-convention": "error",
+      "eslint-comments/no-use": [
+        "error",
+        {
+          allow: [
+            "eslint-disable",
+            "eslint-enable",
+            "eslint-disable-next-line",
+          ],
+        },
+      ],
+      "@typescript-eslint/no-shadow": "error",
+      "one-var": ["error", "never"],
+      "@typescript-eslint/restrict-template-expressions": "off",
+    },
+    "settings": {
+        "import/parsers": {
+            "@typescript-eslint/parser": [".ts", ".tsx"]
+        },
+        "import/resolver": {
+            "typescript": {}
+        }
+    },
+  },
+);