chore(deps): update dependency eslint to v9

.github/workflows/build.yml

@@ -63,3 +63,5 @@ jobs:
         run: pnpm test:coverage
       - name: codecov
         uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}

.github/workflows/release.yml

@@ -53,3 +53,5 @@ jobs:
       - name: codecov # Perform after version publishing
         if: steps.test.outcome == 'success'
         uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}

eslint.config.mjs

@@ -0,0 +1,77 @@
+// @ts-check
+
+import jsEslint from "@eslint/js";
+import eslintConfigPrettier from "eslint-config-prettier";
+import eslintPluginImportX from "eslint-plugin-import-x";
+import * as tsEslint from "typescript-eslint";
+
+export default tsEslint.config(
+  jsEslint.configs.recommended,
+  eslintPluginImportX.flatConfigs.recommended,
+  eslintPluginImportX.flatConfigs.typescript,
+  ...tsEslint.configs.strictTypeChecked,
+  ...tsEslint.configs.stylisticTypeChecked,
+  {
+    languageOptions: {
+      parserOptions: {
+        projectService: {
+          allowDefaultProject: ["*.js", "*.mjs"],
+        },
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
+  },
+  {
+    ignores: [
+      "**/coverage",
+      "**/dist",
+      "**/esbuild.config.mjs",
+      "**/lib/__fixtures__/**/*.ts",
+      "**/jest.config.mjs",
+      "**/smoke-tests",
+    ],
+  },
+  {
+    rules: {
+      "@typescript-eslint/await-thenable": "warn",
+      "@typescript-eslint/explicit-function-return-type": "warn",
+      "@typescript-eslint/no-floating-promises": [
+        "warn",
+        { ignoreIIFE: true, ignoreVoid: false },
+      ],
+      "@typescript-eslint/no-unused-vars": [
+        "warn",
+        { argsIgnorePattern: "^_" },
+      ],
+      "@typescript-eslint/restrict-template-expressions": [
+        "error",
+        {
+          allowNever: true,
+          allowNumber: true,
+        },
+      ],
+      "import-x/no-named-as-default-member": "off",
+      "import-x/no-unresolved": "off",
+      "import-x/order": [
+        "warn",
+        { "newlines-between": "always", alphabetize: { order: "asc" } },
+      ],
+      "no-console": ["warn"],
+    },
+  },
+  {
+    files: ["**/*.spec.ts"],
+    rules: {
+      "@typescript-eslint/explicit-function-return-type": "off",
+      "@typescript-eslint/no-non-null-assertion": "off",
+      "@typescript-eslint/no-unsafe-argument": "off",
+      "@typescript-eslint/no-unsafe-assignment": "off",
+      "@typescript-eslint/no-unsafe-member-access": "off",
+    },
+  },
+  {
+    files: ["**/*.js", "**/*.mjs"],
+    ...tsEslint.configs.disableTypeChecked,
+  },
+  eslintConfigPrettier,
+);

lib/index.spec.ts

@@ -40,6 +40,7 @@ describe("TypeScriptLoader", () => {
         try {
           cfg.load(path.resolve(fixturesPath, "invalid.fixture.ts"));
           fail("Should fail to load invalid TS");
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
         } catch (error: any) {
           expect(error?.name).toStrictEqual("TypeScriptCompileError");
         }
@@ -72,6 +73,7 @@ describe("TypeScriptLoader", () => {
         try {
           await cfg.load(path.resolve(fixturesPath, "invalid.fixture.ts"));
           fail("Should fail to load invalid TS");
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
         } catch (error: any) {
           expect(error?.name).toStrictEqual("TypeScriptCompileError");
         }
@@ -104,7 +106,7 @@ describe("TypeScriptLoader", () => {
 
       expect(() =>
         cfg.load(path.resolve(fixturesPath, "invalid.fixture.ts")),
-      ).toThrowError();
+      ).toThrow();
     });
   });
 });

lib/loader.spec.ts

@@ -37,7 +37,9 @@ describe("TypeScriptLoader", () => {
 
   it("should fail on parsing an invalid TS file", () => {
     const filePath = path.resolve(fixturesPath, "invalid.fixture.ts");
-    expect(() => loader(filePath, readFixtureContent(filePath))).toThrowError();
+    expect((): unknown =>
+      loader(filePath, readFixtureContent(filePath)),
+    ).toThrow();
   });
 
   it("should use the same instance of jiti across multiple calls", () => {
@@ -66,9 +68,9 @@ describe("TypeScriptLoader", () => {
 
     beforeEach(() => {
       stub = jest.spyOn(jiti, "default").mockImplementation((() => () => {
-        // eslint-disable-next-line @typescript-eslint/no-throw-literal
+        // eslint-disable-next-line @typescript-eslint/only-throw-error
         throw unknownError;
-      }) as any);
+      }) as never);
 
       loader = TypeScriptLoader();
     });

lib/loader.ts

@@ -5,9 +5,10 @@ import { TypeScriptCompileError } from "./typescript-compile-error.js";
 
 export function TypeScriptLoader(options?: JITIOptions): Loader {
   const loader = jiti("", { interopDefault: true, ...options });
-  return (path: string) => {
+  return (path: string): unknown => {
     try {
-      const result = loader(path);
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const result: { default?: unknown } = loader(path);
 
       // `default` is used when exporting using export default, some modules
       // may still use `module.exports` or if in TS `export = `

package.json

@@ -37,7 +37,7 @@
     "check:types": "tsc -p tsconfig.json",
     "format": "pnpm format:check --write",
     "format:check": "prettier --check \"{**/*,*}.{js,cjs,mjs,ts}\"",
-    "lint": "eslint --ext \".js,.cjs,.mjs,.ts\" .",
+    "lint": "eslint",
     "lint:fix": "pnpm lint --fix",
     "release": "release-it",
     "test": "jest",
@@ -58,19 +58,19 @@
     "@swc/core": "^1.7.26",
     "@swc/jest": "^0.2.36",
     "@types/jest": "^29.5.13",
-    "@typescript-eslint/eslint-plugin": "^7.18.0",
+    "@typescript-eslint/eslint-plugin": "^8.10.0",
     "chalk": "^5.3.0",
     "cosmiconfig": "^9.0.0",
     "esbuild": "^0.24.0",
-    "eslint": "^8.57.1",
-    "eslint-config-airbnb-typescript": "^18.0.0",
+    "eslint": "^9.13.0",
     "eslint-config-prettier": "^9.1.0",
-    "eslint-plugin-import": "^2.30.0",
-    "eslint-plugin-prettier": "^5.2.1",
+    "eslint-import-resolver-typescript": "^3.6.3",
+    "eslint-plugin-import-x": "^4.3.1",
     "jest": "^29.7.0",
     "prettier": "^3.3.3",
     "release-it": "^17.6.0",
-    "typescript": "^5.6.2"
+    "typescript": "^5.6.2",
+    "typescript-eslint": "^8.10.0"
   },
   "keywords": [
     "cosmiconfig",