angular-docs-cn/packages/core/src/render3/assert.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
 */

// The functions in this file verify that the assumptions we are making
// about state in an instruction are correct before implementing any logic.
// They are meant only to be called in dev mode as sanity checks.

export function assertNumber(actual: any, msg: string) {
  if (typeof actual != 'number') {
    throwError(msg);
  }
}

export function assertEqual<T>(actual: T, expected: T, msg: string) {
  if (actual != expected) {
    throwError(msg);
  }
}

export function assertNotEqual<T>(actual: T, expected: T, msg: string) {
  if (actual == expected) {
    throwError(msg);
  }
}

export function assertSame<T>(actual: T, expected: T, msg: string) {
  if (actual !== expected) {
    throwError(msg);
  }
}

export function assertLessThan<T>(actual: T, expected: T, msg: string) {
  if (actual >= expected) {
    throwError(msg);
  }
}

export function assertGreaterThan<T>(actual: T, expected: T, msg: string) {
  if (actual <= expected) {
    throwError(msg);
  }
}

export function assertNotDefined<T>(actual: T, msg: string) {
  if (actual != null) {
    throwError(msg);
  }
}

export function assertDefined<T>(actual: T, msg: string) {
  if (actual == null) {
    throwError(msg);
  }
}

export function assertComponentType(
    actual: any,
    msg: string =
        'Type passed in is not ComponentType, it does not have \'ngComponentDef\' property.') {
  if (!actual.ngComponentDef) {
    debugger;
    throwError(msg);
  }
}

function throwError(msg: string): never {
  debugger;  // Left intentionally for better debugger experience.
  throw new Error(`ASSERTION ERROR: ${msg}`);
}