node.js - karma : (SystemJS) XHR error (404 Not Found) loading src/node_modules/angular2-jwt/angular2-jwt. js

Question

我正在使用 https://github.com/angular/quickstart 中的 angular2-seed 。我想为我的一门类(class)进行单元测试。以下是我的测试:

describe('my method', () => {
    it('should expect true', () => {
        mockContextSettings = jasmine.createSpyObj('mockContextSettings', ['environment']);
        mockWindow = jasmine.createSpyObj('mockWindow', ['location']);
        workContext = new WorkContext(mockContextSettings, mockWindow);
        expect(true).toBe(true);
    });
});

测试将正确运行，无需

workContext = new WorkContext(mockContextSettings, mockWindow);

但是当我在测试中使用它时，我在 karma 浏览器控制台中收到以下错误:

GET http://localhost:9876/base/src/node_modules/angular2-jwt/angular2-jwt.js 404 (Not Found)

下面是我的 systemjs.config、karma.config.js、karma-test-shim.js:

systemjs.config

/**
 * System configuration for Angular samples
 * Adjust as necessary for your application needs.
 */
(function (global) {
  System.config({
    defaultJSExtensions: true,
    paths: {
      // paths serve as alias
      'npm:': 'node_modules/'
    },
    // map tells the System loader where to look for things
    map: {
      // our app is within the app folder
      app: 'app',

      // angular bundles
      '@angular/core': 'npm:@angular/core/bundles/core.umd.js',
      '@angular/common': 'npm:@angular/common/bundles/common.umd.js',
      '@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
      '@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
      '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
      '@angular/http': 'npm:@angular/http/bundles/http.umd.js',
      '@angular/router': 'npm:@angular/router/bundles/router.umd.js',
      '@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',

      // other libraries
      'rxjs':                      'npm:rxjs',
      'angular-in-memory-web-api': 'npm:angular-in-memory-web-api/bundles/in-memory-web-api.umd.js',
      'angular2-jwt': 'npm:angular2-jwt/angular2-jwt.js',
      'moment': 'npm:moment/min/moment.min.js',
      'moment-timezone': 'npm:moment-timezone/builds/moment-timezone-with-data-2010-2020.min.js'
    },
    // packages tells the System loader how to load when no filename and/or no extension
    packages: {
      app: {
        defaultExtension: 'js'
      },
      rxjs: {
        defaultExtension: 'js'
      }
    }
  });
})(this);

karma.config.js

module.exports = function(config) {

  var appBase    = 'src/';       // transpiled app JS and map files
  var appSrcBase = appBase;      // app source TS files

  // Testing helpers (optional) are conventionally in a folder called `testing`
  var testingBase    = 'testing/'; // transpiled test JS and map files
  var testingSrcBase = 'testing/'; // test source TS files

  config.set({
    basePath: '.',
    frameworks: ['jasmine'],

    plugins: [
      require('karma-jasmine'),
      require('karma-chrome-launcher'),
      require('karma-jasmine-html-reporter')
    ],

    client: {
      builtPaths: [appBase, testingBase], // add more spec base paths as needed
      clearContext: false // leave Jasmine Spec Runner output visible in browser
    },

    customLaunchers: {
      // From the CLI. Not used here but interesting
      // chrome setup for travis CI using chromium
      Chrome_travis_ci: {
        base: 'Chrome',
        flags: ['--no-sandbox']
      }
    },

    files: [
      // System.js for module loading
      'node_modules/systemjs/dist/system.src.js',

      // Polyfills
      'node_modules/core-js/client/shim.js',

      // zone.js
      'node_modules/zone.js/dist/zone.js',
      'node_modules/zone.js/dist/long-stack-trace-zone.js',
      'node_modules/zone.js/dist/proxy.js',
      'node_modules/zone.js/dist/sync-test.js',
      'node_modules/zone.js/dist/jasmine-patch.js',
      'node_modules/zone.js/dist/async-test.js',
      'node_modules/zone.js/dist/fake-async-test.js',

      'node_modules/angular2-jwt/angular2-jwt.js', // <-- added explicitly to see if it fixes the issue

      // RxJs
      { pattern: 'node_modules/rxjs/**/*.js', included: false, watched: false },
      { pattern: 'node_modules/rxjs/**/*.js.map', included: false, watched: false },

      // Paths loaded via module imports:
      // Angular itself
      { pattern: 'node_modules/@angular/**/*.js', included: false, watched: false },
      { pattern: 'node_modules/@angular/**/*.js.map', included: false, watched: false },

      { pattern: appBase + '/systemjs.config.js', included: false, watched: false },
      { pattern: appBase + '/systemjs.config.extras.js', included: false, watched: false },
      'karma-test-shim.js', // optionally extend SystemJS mapping e.g., with barrels

      // transpiled application & spec code paths loaded via module imports
      { pattern: appBase + '**/*.js', included: false, watched: true },
      { pattern: testingBase + '**/*.js', included: false, watched: true },


      // Asset (HTML & CSS) paths loaded via Angular's component compiler
      // (these paths need to be rewritten, see proxies section)
      { pattern: appBase + '**/*.html', included: false, watched: true },
      { pattern: appBase + '**/*.css', included: false, watched: true },

      // Paths for debugging with source maps in dev tools
      { pattern: appBase + '**/*.ts', included: false, watched: false },
      { pattern: appBase + '**/*.js.map', included: false, watched: false },
      { pattern: testingSrcBase + '**/*.ts', included: false, watched: false },
      { pattern: testingBase + '**/*.js.map', included: false, watched: false}
    ],

    // Proxied base paths for loading assets
    proxies: {
      // required for modules fetched by SystemJS
      '/base/src/node_modules/': '/base/node_modules/'
    },

    exclude: [],
    preprocessors: {},
    reporters: ['progress', 'kjhtml'],

    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: ['Chrome'],
    singleRun: false
  })
}

karma-test-shim.js

// /*global jasmine, __karma__, window*/
Error.stackTraceLimit = 0; // "No stacktrace"" is usually best for app testing.

// Uncomment to get full stacktrace output. Sometimes helpful, usually not.
// Error.stackTraceLimit = Infinity; //

jasmine.DEFAULT_TIMEOUT_INTERVAL = 1000;

// builtPaths: root paths for output ("built") files
// get from karma.config.js, then prefix with '/base/' (default is 'src/')
var builtPaths = (__karma__.config.builtPaths || ['src/'])
                 .map(function(p) { return '/base/'+p;});

__karma__.loaded = function () { };

function isJsFile(path) {
  return path.slice(-3) == '.js';
}

function isSpecFile(path) {
  return /\.spec\.(.*\.)?js$/.test(path);
}

// Is a "built" file if is JavaScript file in one of the "built" folders
function isBuiltFile(path) {
  return isJsFile(path) &&
         builtPaths.reduce(function(keep, bp) {
           return keep || (path.substr(0, bp.length) === bp);
         }, false);
}

var allSpecFiles = Object.keys(window.__karma__.files)
  .filter(isSpecFile)
  .filter(isBuiltFile);

System.config({
  // Base URL for System.js calls. 'base/' is where Karma serves files from.
  baseURL: 'base/src',
  // Extend usual application package list with test folder
  packages: { 'testing': { main: 'index.js', defaultExtension: 'js' } },

  // Assume npm: is set in `paths` in systemjs.config
  // Map the angular testing umd bundles
  map: {
    '@angular/core/testing': 'npm:@angular/core/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router/bundles/router-testing.umd.js',
    '@angular/forms/testing': 'npm:@angular/forms/bundles/forms-testing.umd.js',
    'angular2-jwt': 'npm:angular2-jwt/angular2-jwt.js', // <-- added explicitly to see if it fixes the issue
  },
});

System.import('systemjs.config.js')
  .then(importSystemJsExtras)
  .then(initTestBed)
  .then(initTesting);

/** Optional SystemJS configuration extras. Keep going w/o it */
function importSystemJsExtras(){
  return System.import('systemjs.config.extras.js')
  .catch(function(reason) {
    console.log(
      'Warning: System.import could not load the optional "systemjs.config.extras.js". Did you omit it by accident? Continuing without it.'
    );
    console.log(reason);
  });
}

function initTestBed(){
  return Promise.all([
    System.import('@angular/core/testing'),
    System.import('@angular/platform-browser-dynamic/testing')
  ])

  .then(function (providers) {
    var coreTesting    = providers[0];
    var browserTesting = providers[1];

    coreTesting.TestBed.initTestEnvironment(
      browserTesting.BrowserDynamicTestingModule,
      browserTesting.platformBrowserDynamicTesting());
  })
}

// Import all spec files and start karma
function initTesting () {
  return Promise.all(
    allSpecFiles.map(function (moduleName) {
      return System.import(moduleName);
    })
  )
  .then(__karma__.start, __karma__.error);
}

我的 packages.json 依赖项中有 angular2-jwt 并且已经安装了它。我真的不知道问题出在哪里。

更新:

再次运行测试，无缘无故地，这次它加载了 angular2-jwt.js!但还有另一个问题:这个文件有一行: require('...') 所以这次我在 karma 浏览器控制台中收到以下错误:

  Uncaught ReferenceError: require is not defined
  at node_modules/angular2-jwt/angular2-jwt.js:19

Answer 1

尝试改变...

'node_modules/angular2-jwt/angular2-jwt.js'

...到...

{ pattern: 'node_modules/angular2-jwt/angular2-jwt.js', included: false, watched: false }

...在您的 karma.config.js 文件中。

第一行代码告诉 Karma 使用文件的默认值，如下

{ pattern: "your/file/path", included: true, watched: false }

包含该文件会告诉 Karma 使用脚本标记加载文件，如果您使用 systemjs 加载应用程序，这不是您想要的。

我今天刚刚读到这些棘手的配置设置。如果您有兴趣，我已将链接粘贴到下面的文章中。我发现它非常有帮助。

https://psamsotha.github.io/angular/2016/12/16/angular2-testing-karma-systemjs.html