errors.ts

/**
 * @license
 * Copyright Google Inc. 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.io/license
 */
import {InjectorType} from '../di/interface/defs';
import {stringify} from '../util/stringify';

import {TNode} from './interfaces/node';


/** Called when directives inject each other (creating a circular dependency) */
export function throwCyclicDependencyError(token: any): never {
  throw new Error(`Cannot instantiate cyclic dependency! ${token}`);
}

/** Called when there are multiple component selectors that match a given node */
export function throwMultipleComponentError(tNode: TNode): never {
  throw new Error(`Multiple components match node with tagname ${tNode.tagName}`);
}

/** Throws an ExpressionChangedAfterChecked error if checkNoChanges mode is on. */
export function throwErrorIfNoChangesMode(
    creationMode: boolean, oldValue: any, currValue: any): never|void {
  let msg =
      `ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was checked. Previous value: '${oldValue}'. Current value: '${currValue}'.`;
  if (creationMode) {
    msg +=
        ` It seems like the view has been created after its parent and its children have been dirty checked.` +
        ` Has it been created in a change detection hook ?`;
  }
  // TODO: include debug context
  throw new Error(msg);
}

export function throwMixedMultiProviderError() {
  throw new Error(`Cannot mix multi providers and regular providers`);
}

export function throwInvalidProviderError(
    ngModuleType?: InjectorType<any>, providers?: any[], provider?: any) {
  let ngModuleDetail = '';
  if (ngModuleType && providers) {
    const providerDetail = providers.map(v => v == provider ? '?' + provider + '?' : '...');
    ngModuleDetail =
        ` - only instances of Provider and Type are allowed, got: [${providerDetail.join(', ')}]`;
  }

  throw new Error(
      `Invalid provider for the NgModule '${stringify(ngModuleType)}'` + ngModuleDetail);
}