Running a single test file

Question

Is there a way to run ng test for a single file instead of for the entire test suite? Ideally, I'd like to get the quickest possible feedback loop when I'm editing a file, but karma executes the whole suite on each save, which is a bit slow when you build up a big enough test suite.

---

This is different from How to execute only one test spec with angular-cli in that that question is about running an individual spec. This is about running an individual file. The solution involves the same Jasmine spec feature, but the nature of the question is slightly different.

Answer 1

I discovered that Jasmine allows you to prefix describe and it methods with an f (for focus): fdescribe and fit. If you use either of these, Karma will only run the relevant tests. To focus the current file, you can just take the top level describe and change it to fdescribe. If you use Jasmine prior to version 2.1, the focusing keywords are: iit and ddescribe.

This example code runs just the first test:

// Jasmine versions >/=2.1 use 'fdescribe'; versions <2.1 use 'ddescribe'
fdescribe('MySpec1', function () {
    it('should do something', function () {
        // ...
    });
});

describe('MyOtherSpec', function () {
    it('should do something else', function () {
        // ...
    });
});

Here is the Jasmine documentation on Focusing Specs, and here is a related SO article that provides additional thoughtful solutions.

Answer 2

This can be achieved these days via the include option. https://angular.io/cli/test#options

It's a glob match, so as an example:

ng test --include='**/someFolder/*.spec.ts'

I can't find it in the 8.1.0 release notes, but @Swoox mentions below this is a feature after cli version 8.1.0. Thanks for figuring that out.

Answer 3

It's worth mentioning that you can disable particular test without commenting by xdescribe and xit

xdescribe('Hello world', () => { 
  xit('says hello', () => { 
    expect(helloWorld())
        .toEqual('Hello world!');
  });
});

And as somebody already said if you want to focus on some test then fdescribe and fit

fdescribe('Hello world', () => { 
  fit('says hello', () => { 
    expect(helloWorld())
        .toEqual('Hello world!');
  });
});

Answer 4

I found that ng test has an additional option --include which you can use in order to be able to run test for a single file, or for a particular directory, or for a bunch of files:

// one file
npm run test -- --include src/app/components/component/component-name.component.spec.ts

// directory or bunch of files
npm run test -- --include src/app/components

ng cli docs

Answer 5

You can go to src/test.ts and can change the following line:

const context = require.context('./', true, /\.spec\.ts$/);

to

const context = require.context('./', true, /**yourcomponent.component**\.spec\.ts$/);

Answer 6

In Angular 9 I have had luck with the following:

If you want to test a specific file:

ng test --test-file=path/to/your/file.component.spec.ts

If you want to test only what has changed since your last commit (using git or other version control)

ng test --only-changed

If you have multiple projects in your Angular project and/or are using NX, you can specify an Angular project to test:

ng test project-name

---

---

You can also use

ng test --testNamePattern componentname

for something like path/to/your/component/componentname.spec.ts. This will scan every file in every project, and is slower.

Answer 7

Using ng test --main file.spec.ts

Answer 8

Visual Studio Code Extension

The easiest way is to use the vscode-test-explorer extension along with its child angular-karma-test-explorer and jasmine-test-adapter, you'll get a list of current test to run one by one if you want:

This is the same answer i gave at this question, there's some more details there.

Answer 9

You must have to go src/test.ts and can change the following line number code 18:

//Then we find all the tests.
const context = require.context('./', true, /\.spec\.ts$/);

to

//Then we find all the tests.
const context = require.context('./', true, /testing.component\.spec\.ts$/);

Answer 10

Works if you specify your spec file as parameter.

For example:

ng test foo.spec.ts

Hope this helps.