feat(eslint-plugin): improve install flow (#3447)

Author: timdeschryver

modules/eslint-plugin/schematics/ng-add/schema.json

@@ -24,7 +24,7 @@
         "all-requiring-type-checking"
       ],
       "x-prompt": {
-        "message": "Which config would you like to use?",
+        "message": "Which ESLint configuration would you like to use?",
         "type": "list",
         "items": [
           {

modules/store/schematics/ng-add/index.spec.ts

@@ -151,6 +151,8 @@ describe('Store ng-add Schematic', () => {
   it('adds the @ngrx/eslint-plugin schematic', async () => {
     const options = { ...defaultOptions, skipESLintPlugin: false };
 
+    appTree.create('.eslintrc.json', '{}');
+
     await schematicRunner
       .runSchematicAsync('ng-add', options, appTree)
       .toPromise();

modules/store/schematics/ng-add/index.ts

@@ -120,18 +120,21 @@ function addNgRxStoreToPackageJson() {
 
 function addNgRxESLintPlugin() {
   return (host: Tree, context: SchematicContext) => {
-    addPackageToPackageJson(
-      host,
-      'devDependencies',
-      '@ngrx/eslint-plugin',
-      platformVersion
-    );
-
-    const installTaskId = context.addTask(new NodePackageInstallTask());
-    context.addTask(new RunSchematicTask('@ngrx/eslint-plugin', 'ng-add', {}), [
-      installTaskId,
-    ]);
-
+    const eslint = host.read('.eslintrc.json')?.toString('utf-8');
+    if (eslint) {
+      addPackageToPackageJson(
+        host,
+        'devDependencies',
+        '@ngrx/eslint-plugin',
+        platformVersion
+      );
+
+      const installTaskId = context.addTask(new NodePackageInstallTask());
+      context.addTask(
+        new RunSchematicTask('@ngrx/eslint-plugin', 'ng-add', {}),
+        [installTaskId]
+      );
+    }
     return host;
   };
 }