I recently created a new Angular 18 project, and I decided to use the standalone component approach. However, in my IntelliJ IDEA editor, I keep encountering the following error underlined in AppComponent.ts

AppComponent is not declared in any Angular module.

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  standalone: true,
  templateUrl: './appponent.html',
  styleUrls: ['./appponent.css']
})
export class AppComponent {
  title = 'test';
}

The application works fine when I run it using ng serve. However, the IntelliJ IDEA editor keeps showing the error:

AppComponent is not declared in any Angular module.

What I’ve Tried:

• Restarting IntelliJ and the TypeScript service.
• Invalidating caches in IntelliJ.

My Question: Is this error expected when using standalone components in Angular 17/18? If so, how can I resolve it, or is this simply a bug or misconfiguration in IntelliJ IDEA? Do I need to configure anything extra for Angular’s standalone components in IntelliJ?

I recently created a new Angular 18 project, and I decided to use the standalone component approach. However, in my IntelliJ IDEA editor, I keep encountering the following error underlined in AppComponent.ts

AppComponent is not declared in any Angular module.

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  standalone: true,
  templateUrl: './appponent.html',
  styleUrls: ['./appponent.css']
})
export class AppComponent {
  title = 'test';
}

The application works fine when I run it using ng serve. However, the IntelliJ IDEA editor keeps showing the error:

AppComponent is not declared in any Angular module.

What I’ve Tried:

• Restarting IntelliJ and the TypeScript service.
• Invalidating caches in IntelliJ.

My Question: Is this error expected when using standalone components in Angular 17/18? If so, how can I resolve it, or is this simply a bug or misconfiguration in IntelliJ IDEA? Do I need to configure anything extra for Angular’s standalone components in IntelliJ?

• angular
• typescript
• intellij-idea

• Which version of IntelliJ do you use? I am using the latest WebStorm and don't have any issues with my standalone components. – JSON Derulo Commented Nov 18, 2024 at 14:03
• i am using the 2021.2.4 version – ThatGuy1234 Commented Nov 18, 2024 at 14:09

1 Answer 1

You need to update your IntelliJ version, 2021.2.4 is really old. Angular standalone is a feature which was added in 2022. IDEs from 2021 have no chance of knowing about this feature and handling it properly.