angular/packages/platform-browser/testing/src/matchers.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 {ɵgetDOM as getDOM} from '@angular/common';
import {Type, ɵglobal as global} from '@angular/core';
import {ComponentFixture} from '@angular/core/testing';
import {By} from '@angular/platform-browser';
import {childNodesAsList, hasClass, hasStyle, isCommentNode} from './browser_util';


/**
 * Jasmine matchers that check Angular specific conditions.
 *
 * Note: These matchers will only work in a browser environment.
 */
export interface NgMatchers<T = any> extends jasmine.Matchers<T> {
  /**
   * Expect the value to be a `Promise`.
   *
   * @usageNotes
   * ### Example
   *
   * {@example testing/ts/matchers.ts region='toBePromise'}
   */
  toBePromise(): boolean;

  /**
   * Expect the value to be an instance of a class.
   *
   * @usageNotes
   * ### Example
   *
   * {@example testing/ts/matchers.ts region='toBeAnInstanceOf'}
   */
  toBeAnInstanceOf(expected: any): boolean;

  /**
   * Expect the element to have exactly the given text.
   *
   * @usageNotes
   * ### Example
   *
   * {@example testing/ts/matchers.ts region='toHaveText'}
   */
  toHaveText(expected: string): boolean;

  /**
   * Expect the element to have the given CSS class.
   *
   * @usageNotes
   * ### Example
   *
   * {@example testing/ts/matchers.ts region='toHaveCssClass'}
   */
  toHaveCssClass(expected: string): boolean;

  /**
   * Expect the element to have the given CSS styles.
   *
   * @usageNotes
   * ### Example
   *
   * {@example testing/ts/matchers.ts region='toHaveCssStyle'}
   */
  toHaveCssStyle(expected: {[k: string]: string}|string): boolean;

  /**
   * Expect a class to implement the interface of the given class.
   *
   * @usageNotes
   * ### Example
   *
   * {@example testing/ts/matchers.ts region='toImplement'}
   */
  toImplement(expected: any): boolean;

  /**
   * Expect an exception to contain the given error text.
   *
   * @usageNotes
   * ### Example
   *
   * {@example testing/ts/matchers.ts region='toContainError'}
   */
  toContainError(expected: any): boolean;

  /**
   * Expect a component of the given type to show.
   */
  toContainComponent(expectedComponentType: Type<any>, expectationFailOutput?: any): boolean;

  /**
   * Invert the matchers.
   */
  not: NgMatchers<T>;
}

const _global = <any>(typeof window === 'undefined' ? global : window);

/**
 * Jasmine matching function with Angular matchers mixed in.
 *
 * ## Example
 *
 * {@example testing/ts/matchers.ts region='toHaveText'}
 */
export const expect: <T = any>(actual: T) => NgMatchers<T> = _global.expect;


// Some Map polyfills don't polyfill Map.toString correctly, which
// gives us bad error messages in tests.
// The only way to do this in Jasmine is to monkey patch a method
// to the object :-(
(Map as any).prototype['jasmineToString'] = function() {
  const m = this;
  if (!m) {
    return '' + m;
  }
  const res: any[] = [];
  m.forEach((v: any, k: any) => { res.push(`${String(k)}:${String(v)}`); });
  return `{ ${res.join(',')} }`;
};

_global.beforeEach(function() {
  // Custom handler for Map as we use Jasmine 2.4, and support for maps is not
  // added until Jasmine 2.6.
  jasmine.addCustomEqualityTester(function compareMap(actual: any, expected: any): boolean {
    if (actual instanceof Map) {
      let pass = actual.size === expected.size;
      if (pass) {
        actual.forEach((v: any, k: any) => {
          pass = pass && jasmine.matchersUtil.equals(v, expected.get(k));
        });
      }
      return pass;
    } else {
      // TODO(misko): we should change the return, but jasmine.d.ts is not null safe
      return undefined !;
    }
  });
  jasmine.addMatchers({
    toBePromise: function() {
      return {
        compare: function(actual: any) {
          const pass = typeof actual === 'object' && typeof actual.then === 'function';
          return {pass: pass, get message() { return 'Expected ' + actual + ' to be a promise'; }};
        }
      };
    },

    toBeAnInstanceOf: function() {
      return {
        compare: function(actual: any, expectedClass: any) {
          const pass = typeof actual === 'object' && actual instanceof expectedClass;
          return {
            pass: pass,
            get message() {
              return 'Expected ' + actual + ' to be an instance of ' + expectedClass;
            }
          };
        }
      };
    },

    toHaveText: function() {
      return {
        compare: function(actual: any, expectedText: string) {
          const actualText = elementText(actual);
          return {
            pass: actualText == expectedText,
            get message() { return 'Expected ' + actualText + ' to be equal to ' + expectedText; }
          };
        }
      };
    },

    toHaveCssClass: function() {
      return {compare: buildError(false), negativeCompare: buildError(true)};

      function buildError(isNot: boolean) {
        return function(actual: any, className: string) {
          return {
            pass: hasClass(actual, className) == !isNot,
            get message() {
              return `Expected ${actual.outerHTML} ${isNot ? 'not ' : ''}to contain the CSS class "${className}"`;
            }
          };
        };
      }
    },

    toHaveCssStyle: function() {
      return {
        compare: function(actual: any, styles: {[k: string]: string}|string) {
          let allPassed: boolean;
          if (typeof styles === 'string') {
            allPassed = hasStyle(actual, styles);
          } else {
            allPassed = Object.keys(styles).length !== 0;
            Object.keys(styles).forEach(
                prop => { allPassed = allPassed && hasStyle(actual, prop, styles[prop]); });
          }

          return {
            pass: allPassed,
            get message() {
              const expectedValueStr = typeof styles === 'string' ? styles : JSON.stringify(styles);
              return `Expected ${actual.outerHTML} ${!allPassed ? ' ' : 'not '}to contain the
                      CSS ${typeof styles === 'string' ? 'property' : 'styles'} "${expectedValueStr}"`;
            }
          };
        }
      };
    },

    toContainError: function() {
      return {
        compare: function(actual: any, expectedText: any) {
          const errorMessage = actual.toString();
          return {
            pass: errorMessage.indexOf(expectedText) > -1,
            get message() { return 'Expected ' + errorMessage + ' to contain ' + expectedText; }
          };
        }
      };
    },

    toImplement: function() {
      return {
        compare: function(actualObject: any, expectedInterface: any) {
          const intProps = Object.keys(expectedInterface.prototype);

          const missedMethods: any[] = [];
          intProps.forEach((k) => {
            if (!actualObject.constructor.prototype[k]) missedMethods.push(k);
          });

          return {
            pass: missedMethods.length == 0,
            get message() {
              return 'Expected ' + actualObject + ' to have the following methods: ' +
                  missedMethods.join(', ');
            }
          };
        }
      };
    },

    toContainComponent: function() {
      return {
        compare: function(actualFixture: any, expectedComponentType: Type<any>) {
          const failOutput = arguments[2];
          const msgFn = (msg: string): string => [msg, failOutput].filter(Boolean).join(', ');

          // verify correct actual type
          if (!(actualFixture instanceof ComponentFixture)) {
            return {
              pass: false,
              message: msgFn(
                  `Expected actual to be of type \'ComponentFixture\' [actual=${actualFixture.constructor.name}]`)
            };
          }

          const found = !!actualFixture.debugElement.query(By.directive(expectedComponentType));
          return found ?
              {pass: true} :
              {pass: false, message: msgFn(`Expected ${expectedComponentType.name} to show`)};
        }
      };
    }
  });
});

function elementText(n: any): string {
  const hasNodes = (n: any) => {
    const children = n.childNodes;
    return children && children.length > 0;
  };

  if (n instanceof Array) {
    return n.map(elementText).join('');
  }

  if (isCommentNode(n)) {
    return '';
  }

  if (getDOM().isElementNode(n) && (n as Element).tagName == 'CONTENT') {
    return elementText(Array.prototype.slice.apply((<any>n).getDistributedNodes()));
  }

  if (hasShadowRoot(n)) {
    return elementText(childNodesAsList((<any>n).shadowRoot));
  }

  if (hasNodes(n)) {
    return elementText(childNodesAsList(n));
  }

  return (n as any).textContent;
}

function hasShadowRoot(node: any): boolean {
  return node.shadowRoot != null && node instanceof HTMLElement;
}