Unknown provider $$angularInjectorProvider issue with testing a service downgraded with UpgradeModule. The downgraded service is used by the run() method of the angular 1 module, which is where the error is coming from. Commenting out the run() method causes the test to pass. Note the beforeEach.ts file, which attempts to bring in the AppModule for the tests.

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <title>angular2 playground</title>
    
    <!-- Angular 2 Dependencies -->
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/proxy.js"></script>
    <script src="https://unpkg.com/zone.js/dist/sync-test.js"></script>
    <script src="https://unpkg.com/zone.js/dist/async-test.js"></script>
    <script src="https://unpkg.com/zone.js/dist/fake-async-test.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    
    <!-- Jasmine -->
    <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.5.2/jasmine.css">
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.5.2/jasmine.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.5.2/jasmine-html.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.5.2/boot.js"></script>
    <script src="https://unpkg.com/zone.js/dist/jasmine-patch.js"></script>
    <script>
      // Hack to start the tests after SystemJS has loaded its modules
      var jasmineOnLoad = window.onload;
      window.onload = function() {};
    </script>
    
    <!-- Angular 1 -->
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.0/angular.min.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.0/angular-mocks.js"></script>
    
    <script src="src/angular1.module.js"></script>
    <script src="src/a1-test-component.js"></script>
    
    <!-- Import and run tests -->
    <script>
      Promise.all([
        System.import('@angular/core/testing'),
        System.import('@angular/platform-browser-dynamic/testing'),
        System.import('src/beforeEach'),
        System.import('src/a1-test-component.spec')
      ])
        .then(function(modules) {
          var coreTesting = modules[ 0 ];
          var browserTesting = modules[ 1 ];
      
          coreTesting.TestBed.initTestEnvironment(
            browserTesting.BrowserDynamicTestingModule,
            browserTesting.platformBrowserDynamicTesting());
        })
        .then(jasmineOnLoad)  // start the tests
        .catch(console.error.bind(console));
    </script>
  </head>

  <body>
  </body>

</html>

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    'app': './src',
    
    '@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',
    '@angular/upgrade/static': 'npm:@angular/upgrade/bundles/upgrade-static.umd.js',
    
    '@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',
    
    'rxjs': 'npm:rxjs',
    'typescript': 'npm:typescript@2.0.2/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { UpgradeModule, downgradeComponent, downgradeInjectable } from '@angular/upgrade/static';
import { AppComponent } from './app.component';
import { Angular2Service } from './angular2.service';

// Downgrade Angular 2 Service to Angular 1
angular.module( 'testApp' )
  .factory( 'Angular2Service', downgradeInjectable( Angular2Service ) );


@NgModule({
  imports: [ BrowserModule, UpgradeModule ],
  providers : [ Angular2Service ]
})
export class AppModule {
  ngDoBootstrap() {}
}

angular.module( 'testApp', [] );

//
// *** Comment out the below block to see the test pass
//
angular.module( 'testApp' )
  .run( [ 'Angular2Service', Angular2Service => {
    Angular2Service.showTestMessage();
  } ] );

import { Injectable } from '@angular/core';

/**
 * Just an example Angular 2 service which is downgraded
 * to be run from Angular 1
 */
@Injectable()
export class Angular2Service {

  showTestMessage() {
    var msg = "Test Message from Angular 2 Service!";
    
    document.body.appendChild( document.createTextNode( msg ) );
  }
  
}

/**
 * This is an example component test, such as one that 
 * is within our app.
 * 
 * If 'Angular2Service' is not injected into the run()
 * method of angular1.module.ts, this component test 
 * passes.
 */
describe( 'testComponent', () => {
  var $compile,
      $scope;
  
  beforeEach( module( 'testApp' ) );
  
  beforeEach( inject( $injector => {
    $compile = $injector.get( '$compile' );
    $scope = $injector.get( '$rootScope' ).$new();
  } ) );
  
  
  it( 'should show the text "Test Component" in the DOM', () => {
    var element = $compile( '<test-component></test-component>' )( $scope );
    $scope.$apply();
    
    expect( element[ 0 ].innerHTML ).toBe( 'Test Component' );
  } );
  
} );

/**
 * This is an example component, such as one that is 
 * tested within our app.
 * 
 * If 'Angular2Service' is not injected into the run()
 * method of angular1.module.ts, this component's test 
 * passes.
 */
angular.module( 'testApp' ).component( 'testComponent', {
  template: 'Test Component'
} );

import { async, TestBed } from '@angular/core/testing';
import { AppModule } from './app.module';

beforeEach( async( () => {
  TestBed.configureTestingModule( {
    imports : [ AppModule ]
  } )
    .compileComponents();
} ) );