Only Run One Suite or Spec in Jasmine

My team uses Karma (and thus Jasmine) to test our AngularJS applications. Sometimes when a single test is failing, it’s a pain to re-run every test while you iterate on a fix.

Turns out there’s a way to only run a single suite of tests, or even a single test.

Suppose you have the following tests:

describe(“my feature a”, function() {
    it(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

describe(“my feature b”, function() {
    it(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

If you have tests failing in “my feature a”, you can just run those tests by changing the describe call to a ddescribe call.

// Only this suite will run
ddescribe(“my feature a”, function() {
    it(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

describe(“my feature b”, function() {
    it(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

If you’ve narrowed down to a single spec, you can re-run that single spec by changing it to iit.

describe(“my feature a”, function() {
    // Only this spec will run
    iit(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

describe(“my feature b”, function() {
    it(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

If you want to run multiple specs, you do that by simply changing each to iit.

describe(“my feature a”, function() {
    // This spec will run
    iit(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

describe(“my feature b”, function() {
    // This spec will run
    iit(“has a foo”, function() {
        // ...
    });

    it(“has a bar”, function() {
        // ...
    });
});

This was a pretty useful discovery for me. Hopefully it is for you as well.

Update: David Ruttka has pointed out that you can also use xdescribe and xit to disable individual suites and tests.

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