From e07b5d53e23c9ba549377d18eb091490e567c544 Mon Sep 17 00:00:00 2001
From: Alan Agius <alanagius@google.com>
Date: Tue, 23 Jan 2024 10:25:03 +0000
Subject: [PATCH] fix(@schematics/angular): retain trailing comma when adding
 providers to app config

This fixes an issue which caused the new provider to be added in the position of the trailing comma. With this change the trailing comma is retained.

Closes #26911
---
 .../angular/utility/standalone/rules.ts       |  4 +--
 .../angular/utility/standalone/rules_spec.ts  | 31 +++++++++++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/packages/schematics/angular/utility/standalone/rules.ts b/packages/schematics/angular/utility/standalone/rules.ts
index ba8e574d4fc2..2f7a083f20c1 100644
--- a/packages/schematics/angular/utility/standalone/rules.ts
+++ b/packages/schematics/angular/utility/standalone/rules.ts
@@ -231,12 +231,10 @@ function addProvidersExpressionToAppConfig(
   // If there's a `providers` property, we can add the provider
   // to it, otherwise we need to declare it ourselves.
   if (providersLiteral) {
-    const hasTrailingComma = providersLiteral.elements.hasTrailingComma;
-
     applyChangesToFile(tree, filePath, [
       insertAfterLastOccurrence(
         providersLiteral.elements,
-        (hasTrailingComma || providersLiteral.elements.length === 0 ? '' : ', ') + expression,
+        (providersLiteral.elements.length === 0 ? '' : ', ') + expression,
         filePath,
         providersLiteral.getStart() + 1,
       ),
diff --git a/packages/schematics/angular/utility/standalone/rules_spec.ts b/packages/schematics/angular/utility/standalone/rules_spec.ts
index d79557a5f730..7a5cabd69074 100644
--- a/packages/schematics/angular/utility/standalone/rules_spec.ts
+++ b/packages/schematics/angular/utility/standalone/rules_spec.ts
@@ -445,5 +445,36 @@ describe('standalone utilities', () => {
       assertContains(content, `import { provideModule } from '@my/module';`);
       assertContains(content, `providers: [provideModule([])]`);
     });
+
+    it('should add a root provider to a standalone app when providers contain a trailing comma', async () => {
+      await setupProject(true);
+
+      const configPath = 'app/app.config.ts';
+      host.overwrite(
+        getPathWithinProject(configPath),
+        `
+        import { ApplicationConfig } from '@angular/core';
+        import { provideRouter } from '@angular/router';
+
+        export const appConfig: ApplicationConfig = {
+          providers: [
+            provideRouter([]),
+          ]
+        };
+      `,
+      );
+
+      await testRule(
+        addRootProvider(
+          projectName,
+          ({ code, external }) => code`${external('provideModule', '@my/module')}([])`,
+        ),
+        host,
+      );
+
+      const content = readFile('app/app.config.ts');
+      assertContains(content, `import { provideModule } from '@my/module';`);
+      assertContains(content, `providers: [provideRouter([]),provideModule([]),]`);
+    });
   });
 });