Mock underscore in jasmine/angular test











up vote
1
down vote

favorite












In a component, I have the following method:



import _ from 'underscore';


@Component({
selector: 'hello-selector',
templateUrl: './hello.component.html'
)}
export class Hello implements OnInit{

...
public arrayHello(): Array {
return _.chain(...)
...
}
...

ngOnInit(): void {
myarray = this.arrayHello();
}


The default test case in the angular spec file failed with the error




TypeError: Cannot read property 'chain' of undefined




How to Mock underscore in order to deal with this error?



I already tried the following but it does not seems to be the right way: spyOn(_, 'chain').and.callFake((f => f()));










share|improve this question




























    up vote
    1
    down vote

    favorite












    In a component, I have the following method:



    import _ from 'underscore';


    @Component({
    selector: 'hello-selector',
    templateUrl: './hello.component.html'
    )}
    export class Hello implements OnInit{

    ...
    public arrayHello(): Array {
    return _.chain(...)
    ...
    }
    ...

    ngOnInit(): void {
    myarray = this.arrayHello();
    }


    The default test case in the angular spec file failed with the error




    TypeError: Cannot read property 'chain' of undefined




    How to Mock underscore in order to deal with this error?



    I already tried the following but it does not seems to be the right way: spyOn(_, 'chain').and.callFake((f => f()));










    share|improve this question


























      up vote
      1
      down vote

      favorite









      up vote
      1
      down vote

      favorite











      In a component, I have the following method:



      import _ from 'underscore';


      @Component({
      selector: 'hello-selector',
      templateUrl: './hello.component.html'
      )}
      export class Hello implements OnInit{

      ...
      public arrayHello(): Array {
      return _.chain(...)
      ...
      }
      ...

      ngOnInit(): void {
      myarray = this.arrayHello();
      }


      The default test case in the angular spec file failed with the error




      TypeError: Cannot read property 'chain' of undefined




      How to Mock underscore in order to deal with this error?



      I already tried the following but it does not seems to be the right way: spyOn(_, 'chain').and.callFake((f => f()));










      share|improve this question















      In a component, I have the following method:



      import _ from 'underscore';


      @Component({
      selector: 'hello-selector',
      templateUrl: './hello.component.html'
      )}
      export class Hello implements OnInit{

      ...
      public arrayHello(): Array {
      return _.chain(...)
      ...
      }
      ...

      ngOnInit(): void {
      myarray = this.arrayHello();
      }


      The default test case in the angular spec file failed with the error




      TypeError: Cannot read property 'chain' of undefined




      How to Mock underscore in order to deal with this error?



      I already tried the following but it does not seems to be the right way: spyOn(_, 'chain').and.callFake((f => f()));







      angular mocking underscore.js karma-jasmine






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 19 at 10:02









      Philipp Meissner

      1,86911531




      1,86911531










      asked Nov 19 at 9:51









      billyjov

      658314




      658314
























          1 Answer
          1






          active

          oldest

          votes

















          up vote
          0
          down vote













          You can create mock Object for underscore.



          import _ from './test-data/UnderscoreMock';


          And use UnderscoreMock:



          ./test-data/UnderscoreMock



          export default const _ {
          chain: () => {}
          ....
          }


          and set UnderscoreMock in component.



          Second you can use spyOn into component.



          spyOn(INSTANCE_COMPONENT, "chain"); 





          share|improve this answer





















          • always get an undefined
            – billyjov
            Nov 19 at 10:13










          • can trying const spyChain = (window._, 'chain').and.callFake(() => {})
            – Konstantin Okhotnick
            Nov 19 at 10:16










          • and expect(spyChain.chain).toHaveBeenCalled();
            – Konstantin Okhotnick
            Nov 19 at 10:18










          • not working yet for the case
            – billyjov
            Nov 19 at 10:21










          • Yes, I think you need to wrap up chain in method or check value how you get with chain
            – Konstantin Okhotnick
            Nov 19 at 12:37











          Your Answer






          StackExchange.ifUsing("editor", function () {
          StackExchange.using("externalEditor", function () {
          StackExchange.using("snippets", function () {
          StackExchange.snippets.init();
          });
          });
          }, "code-snippets");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "1"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53372039%2fmock-underscore-in-jasmine-angular-test%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          0
          down vote













          You can create mock Object for underscore.



          import _ from './test-data/UnderscoreMock';


          And use UnderscoreMock:



          ./test-data/UnderscoreMock



          export default const _ {
          chain: () => {}
          ....
          }


          and set UnderscoreMock in component.



          Second you can use spyOn into component.



          spyOn(INSTANCE_COMPONENT, "chain"); 





          share|improve this answer





















          • always get an undefined
            – billyjov
            Nov 19 at 10:13










          • can trying const spyChain = (window._, 'chain').and.callFake(() => {})
            – Konstantin Okhotnick
            Nov 19 at 10:16










          • and expect(spyChain.chain).toHaveBeenCalled();
            – Konstantin Okhotnick
            Nov 19 at 10:18










          • not working yet for the case
            – billyjov
            Nov 19 at 10:21










          • Yes, I think you need to wrap up chain in method or check value how you get with chain
            – Konstantin Okhotnick
            Nov 19 at 12:37















          up vote
          0
          down vote













          You can create mock Object for underscore.



          import _ from './test-data/UnderscoreMock';


          And use UnderscoreMock:



          ./test-data/UnderscoreMock



          export default const _ {
          chain: () => {}
          ....
          }


          and set UnderscoreMock in component.



          Second you can use spyOn into component.



          spyOn(INSTANCE_COMPONENT, "chain"); 





          share|improve this answer





















          • always get an undefined
            – billyjov
            Nov 19 at 10:13










          • can trying const spyChain = (window._, 'chain').and.callFake(() => {})
            – Konstantin Okhotnick
            Nov 19 at 10:16










          • and expect(spyChain.chain).toHaveBeenCalled();
            – Konstantin Okhotnick
            Nov 19 at 10:18










          • not working yet for the case
            – billyjov
            Nov 19 at 10:21










          • Yes, I think you need to wrap up chain in method or check value how you get with chain
            – Konstantin Okhotnick
            Nov 19 at 12:37













          up vote
          0
          down vote










          up vote
          0
          down vote









          You can create mock Object for underscore.



          import _ from './test-data/UnderscoreMock';


          And use UnderscoreMock:



          ./test-data/UnderscoreMock



          export default const _ {
          chain: () => {}
          ....
          }


          and set UnderscoreMock in component.



          Second you can use spyOn into component.



          spyOn(INSTANCE_COMPONENT, "chain"); 





          share|improve this answer












          You can create mock Object for underscore.



          import _ from './test-data/UnderscoreMock';


          And use UnderscoreMock:



          ./test-data/UnderscoreMock



          export default const _ {
          chain: () => {}
          ....
          }


          and set UnderscoreMock in component.



          Second you can use spyOn into component.



          spyOn(INSTANCE_COMPONENT, "chain"); 






          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Nov 19 at 10:02









          Konstantin Okhotnick

          946718




          946718












          • always get an undefined
            – billyjov
            Nov 19 at 10:13










          • can trying const spyChain = (window._, 'chain').and.callFake(() => {})
            – Konstantin Okhotnick
            Nov 19 at 10:16










          • and expect(spyChain.chain).toHaveBeenCalled();
            – Konstantin Okhotnick
            Nov 19 at 10:18










          • not working yet for the case
            – billyjov
            Nov 19 at 10:21










          • Yes, I think you need to wrap up chain in method or check value how you get with chain
            – Konstantin Okhotnick
            Nov 19 at 12:37


















          • always get an undefined
            – billyjov
            Nov 19 at 10:13










          • can trying const spyChain = (window._, 'chain').and.callFake(() => {})
            – Konstantin Okhotnick
            Nov 19 at 10:16










          • and expect(spyChain.chain).toHaveBeenCalled();
            – Konstantin Okhotnick
            Nov 19 at 10:18










          • not working yet for the case
            – billyjov
            Nov 19 at 10:21










          • Yes, I think you need to wrap up chain in method or check value how you get with chain
            – Konstantin Okhotnick
            Nov 19 at 12:37
















          always get an undefined
          – billyjov
          Nov 19 at 10:13




          always get an undefined
          – billyjov
          Nov 19 at 10:13












          can trying const spyChain = (window._, 'chain').and.callFake(() => {})
          – Konstantin Okhotnick
          Nov 19 at 10:16




          can trying const spyChain = (window._, 'chain').and.callFake(() => {})
          – Konstantin Okhotnick
          Nov 19 at 10:16












          and expect(spyChain.chain).toHaveBeenCalled();
          – Konstantin Okhotnick
          Nov 19 at 10:18




          and expect(spyChain.chain).toHaveBeenCalled();
          – Konstantin Okhotnick
          Nov 19 at 10:18












          not working yet for the case
          – billyjov
          Nov 19 at 10:21




          not working yet for the case
          – billyjov
          Nov 19 at 10:21












          Yes, I think you need to wrap up chain in method or check value how you get with chain
          – Konstantin Okhotnick
          Nov 19 at 12:37




          Yes, I think you need to wrap up chain in method or check value how you get with chain
          – Konstantin Okhotnick
          Nov 19 at 12:37


















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Stack Overflow!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          To learn more, see our tips on writing great answers.





          Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


          Please pay close attention to the following guidance:


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53372039%2fmock-underscore-in-jasmine-angular-test%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          If I really need a card on my start hand, how many mulligans make sense? [duplicate]

          Alcedinidae

          Can an atomic nucleus contain both particles and antiparticles? [duplicate]