chore: migrate to ESLint flat config (#320)

Author: json-derulo

.eslintrc.json

@@ -0,0 +1,68 @@
+import angularEslintPlugin from "@angular-eslint/eslint-plugin";
+import angularEslintPluginTemplate from "@angular-eslint/eslint-plugin-template";
+import angularEslintTemplateParser from "@angular-eslint/template-parser";
+import js from "@eslint/js";
+import prettier from "eslint-config-prettier";
+import deprecation from "eslint-plugin-deprecation";
+import globals from "globals";
+import tseslint from "typescript-eslint";
+
+export default [
+  js.configs.recommended,
+  { ignores: ["dist/", ".angular/", "**/*.js"] },
+  {
+    files: ["**/*.ts"],
+    languageOptions: {
+      parser: tseslint.parser,
+      parserOptions: {
+        project: [
+          "./projects/angular-ecmascript-intl/tsconfig.lib.json",
+          "./projects/angular-ecmascript-intl/tsconfig.spec.json",
+          "./projects/angular-intl-demo/tsconfig.app.json",
+        ],
+      },
+      globals: {
+        ...globals.browser,
+      },
+    },
+    plugins: {
+      "@typescript-eslint": tseslint.plugin,
+      deprecation,
+      "@angular-eslint": angularEslintPlugin,
+    },
+    processor: angularEslintPluginTemplate.processors["extract-inline-html"],
+    rules: {
+      ...tseslint.configs.strictTypeChecked.rules,
+      ...tseslint.configs.stylisticTypeChecked.rules,
+      ...angularEslintPlugin.configs.recommended.rules,
+      "@typescript-eslint/no-extraneous-class": "off",
+      "no-unused-vars": "off",
+      "@typescript-eslint/no-unused-vars": "error",
+      "@typescript-eslint/prefer-literal-enum-member": "off",
+      "deprecation/deprecation": "error",
+      "@angular-eslint/prefer-standalone-component": "error",
+    },
+  },
+  {
+    files: ["**/*.spec.ts"],
+    languageOptions: {
+      globals: {
+        ...globals.jasmine,
+      },
+    },
+  },
+  {
+    files: ["**/*.html"],
+    plugins: {
+      "@angular-eslint/template": angularEslintPluginTemplate,
+    },
+    languageOptions: {
+      parser: angularEslintTemplateParser,
+    },
+    rules: {
+      ...angularEslintPluginTemplate.configs.recommended.rules,
+      "@angular-eslint/template/prefer-control-flow": "error",
+    },
+  },
+  prettier,
+];

eslint.config.mjs

@@ -9,7 +9,7 @@
     "build-app": "ng build angular-intl-demo",
     "watch": "ng build --watch --configuration development",
     "test": "ng test --code-coverage=true",
-    "lint": "eslint --ignore-path=.gitignore .",
+    "lint": "eslint .",
     "release": "release-it",
     "prettier": "prettier . --write"
   },
@@ -42,14 +42,14 @@
     "@angular-eslint/template-parser": "^17.0.0",
     "@angular/cli": "~17.3.0",
     "@angular/compiler-cli": "~17.3.0",
+    "@eslint/js": "^9.2.0",
     "@types/jasmine": "~5.1.0",
-    "@typescript-eslint/eslint-plugin": "^7.0.0",
-    "@typescript-eslint/parser": "^7.0.0",
     "cpy-cli": "^5.0.0",
     "dayjs": "^1.11.7",
     "eslint": "^8.53.0",
     "eslint-config-prettier": "^9.0.0",
     "eslint-plugin-deprecation": "^2.0.0",
+    "globals": "^15.1.0",
     "jasmine-core": "~5.1.0",
     "karma": "~6.4.0",
     "karma-chrome-launcher": "~3.2.0",
@@ -61,6 +61,7 @@
     "ng-packagr": "~17.3.0",
     "prettier": "~3.2.0",
     "prettier-plugin-organize-imports": "^3.2.3",
-    "typescript": "~5.4.0"
+    "typescript": "~5.4.0",
+    "typescript-eslint": "^7.0.0"
   }
 }