fix(react): skip adding comma to config when adding remote to host if… (#20620)

packages/react/src/module-federation/ast-utils.spec.ts

@@ -89,6 +89,41 @@ describe('addRemoteToConfig', () => {
 
     expect(result).toEqual(sourceCode);
   });
+
+  it('should not add comma if the existing array has a trailing comma', async () => {
+    const sourceCode = stripIndents`
+      module.exports = {
+        name: 'shell',
+        remotes: [
+          'app1',
+          'app2',
+        ]
+      };
+    `;
+
+    const source = ts.createSourceFile(
+      '/module-federation.config.js',
+      sourceCode,
+      ts.ScriptTarget.Latest,
+      true
+    );
+
+    const result = applyChangesToString(
+      sourceCode,
+      addRemoteToConfig(source, 'new-app')
+    );
+
+    expect(result).toEqual(stripIndents`
+      module.exports = {
+        name: 'shell',
+        remotes: [
+          'app1',
+          'app2',
+          'new-app',
+        ]
+      };
+    `);
+  });
 });
 
 describe('addRemoteDefinition', () => {

packages/react/src/module-federation/ast-utils.ts

@@ -37,7 +37,7 @@ export function addRemoteToConfig(
     const lastElement =
       arrayExpression.elements[arrayExpression.elements.length - 1];
     return [
-      lastElement
+      lastElement && !arrayExpression.elements.hasTrailingComma
         ? {
             type: ChangeType.Insert,
             index: lastElement.end,