Add ESLint on angular 20

Author: ganatan

frontend-angular/angular.json

@@ -85,8 +85,22 @@
               "src/styles.css"
             ]
           }
+        },
+        "lint": {
+          "builder": "@angular-eslint/builder:lint",
+          "options": {
+            "lintFilePatterns": [
+              "src/**/*.ts",
+              "src/**/*.html"
+            ]
+          }
         }
       }
     }
+  },
+  "cli": {
+    "schematicCollections": [
+      "angular-eslint"
+    ]
   }
 }

frontend-angular/eslint.config.js

@@ -0,0 +1,57 @@
+// @ts-check
+const eslint = require("@eslint/js");
+const tseslint = require("typescript-eslint");
+const angular = require("angular-eslint");
+
+module.exports = tseslint.config(
+  {
+    files: ["**/*.ts"],
+    extends: [
+      eslint.configs.recommended,
+      ...tseslint.configs.recommended,
+      ...tseslint.configs.stylistic,
+      ...angular.configs.tsRecommended,
+    ],
+    processor: angular.processInlineTemplates,
+    rules: {
+      "@angular-eslint/directive-selector": [
+        "error",
+        {
+          type: "attribute",
+          prefix: "app",
+          style: "camelCase",
+        },
+      ],
+      "@angular-eslint/component-selector": [
+        "error",
+        {
+          type: "element",
+          prefix: "app",
+          style: "kebab-case",
+        },
+      ],
+      "@angular-eslint/component-class-suffix": [
+        "error",
+        {
+          suffixes: ["","Component"] 
+        }
+      ],
+      "no-undefined": "error",
+      "no-var": "error",
+      "prefer-const": "error",
+      "func-names": "error",
+      "id-length": "error",
+      "newline-before-return": "error",
+      "space-before-blocks": "error",
+      "no-alert": "error"             
+    },
+  },
+  {
+    files: ["**/*.html"],
+    extends: [
+      ...angular.configs.templateRecommended,
+      ...angular.configs.templateAccessibility,
+    ],
+    rules: {},
+  }
+);