/**

* @license

* Copyright Google LLC All Rights Reserved.

*

* Use of this source code is governed by an MIT-style license that can be

* found in the LICENSE file at https://angular.dev/license

*/

import {inject, InjectionToken} from './di';

import {getOriginalError} from './util/errors';

import {NgZone} from './zone';

/**

* Provides a hook for centralized exception handling.

*

* The default implementation of `ErrorHandler` prints error messages to the `console`. To

* intercept error handling, write a custom exception handler that replaces this default as

* appropriate for your app.

*

* @usageNotes

* ### Example

*

* ```

* class MyErrorHandler implements ErrorHandler {

* handleError(error) {

* // do something with the exception

* }

* }

*

* @NgModule({

* providers: [{provide: ErrorHandler, useClass: MyErrorHandler}]

* })

* class MyModule {}

* ```

*

* @publicApi

*/

export class ErrorHandler {

/**

* @internal

*/

_console: Console = console;

handleError(error: any): void {

const originalError = this._findOriginalError(error);

this._console.error('ERROR', error);

if (originalError) {

this._console.error('ORIGINAL ERROR', originalError);

}

}

/** @internal */

_findOriginalError(error: any): Error | null {

let e = error && getOriginalError(error);

while (e && getOriginalError(e)) {

e = getOriginalError(e);

}

return e || null;

}

}

/**

* `InjectionToken` used to configure how to call the `ErrorHandler`.

*

* `NgZone` is provided by default today so the default (and only) implementation for this

* is calling `ErrorHandler.handleError` outside of the Angular zone.

*/

export const INTERNAL_APPLICATION_ERROR_HANDLER = new InjectionToken<(e: any) => void>(

typeof ngDevMode === 'undefined' || ngDevMode ? 'internal error handler' : '',

{

providedIn: 'root',

factory: () => {

const zone = inject(NgZone);

const userErrorHandler = inject(ErrorHandler);

return (e: unknown) => zone.runOutsideAngular(() => userErrorHandler.handleError(e));

},

},

);