[Refactor] Fix incorrect Promise.all usage in app preDeployValidation

Corrected the Promise.all([this.allExtensions.map(...)]) anti-pattern
to properly await extension validations. Added a regression test to
ensure that rejections in extension validation are correctly caught
by the app's preDeployValidation method.

Author: gonzaloriestra

packages/app/src/cli/models/app/app.test.ts

@@ -851,3 +851,37 @@ function createPackageJson(tmpDir: string, type: string, version: string) {
   const dirPath = joinPath(tmpDir, 'node_modules', '@shopify', type)
   return mkdir(dirPath).then(() => writeFile(packagePath, JSON.stringify(packageJson)))
 }
+
+describe('preDeployValidation awaiting', () => {
+  test('awaits extension validation and catches rejections', async () => {
+    // Given
+    const extension = await testUIExtension()
+    vi.spyOn(extension, 'preDeployValidation').mockRejectedValue(new Error('Validation failed'))
+
+    const app = testApp({
+      allExtensions: [extension],
+    })
+
+    // When / Then
+    await expect(app.preDeployValidation()).rejects.toThrow('Validation failed')
+  })
+
+  test('awaits validation for multiple extensions and catches rejections', async () => {
+    // Given
+    const validExtension = await testUIExtension()
+    const invalidExtension = await testUIExtension()
+    const validPreDeployValidation = vi.spyOn(validExtension, 'preDeployValidation').mockResolvedValue()
+    const invalidPreDeployValidation = vi
+      .spyOn(invalidExtension, 'preDeployValidation')
+      .mockRejectedValue(new Error('Validation failed'))
+
+    const app = testApp({
+      allExtensions: [validExtension, invalidExtension],
+    })
+
+    // When / Then
+    await expect(app.preDeployValidation()).rejects.toThrow('Validation failed')
+    expect(validPreDeployValidation).toHaveBeenCalledOnce()
+    expect(invalidPreDeployValidation).toHaveBeenCalledOnce()
+  })
+})

packages/app/src/cli/models/app/app.ts

@@ -405,7 +405,7 @@ export class App<
       }
     }
 
-    await Promise.all([this.allExtensions.map((ext) => ext.preDeployValidation())])
+    await Promise.all(this.allExtensions.map((ext) => ext.preDeployValidation()))
   }
 
   extensionsForType(specification: {identifier: string; externalIdentifier: string}): ExtensionInstance[] {