仅在先前的异步测试通过后，如何运行Mocha测试？

Question

Using the mocha javascript testing framework, I want to be able to have several tests (all asynchronous) only execute after the previously defined test has passed.

I don't want to have to nest these tests within each other.

describe("BBController", function() {
    it("should save", function(done) {});
    it("should delete", function(done) {});
})

Answer 1

Use the --bail option. Make sure you are using at least mocha 0.14.0. (I've tried it with older versions without success.)

First, there's nothing you need to do for mocha to run a test only after the previous one has finished. That's how mocha works by default. Save this to test.js :

describe("test", function () {
    this.timeout(5 * 1000); // Tests time out in 5 seconds.

    it("first", function (done) {
        console.log("first: do nothing");
        done();
    });

    it("second", function (done) {
        console.log("second is executing");
        // This test will take 2.5 seconds.
        setTimeout(function () {
            done();
        }, 2.5 * 1000);
    });

    it("third", function (done) {
        console.log("third is executing");
        // This test will time out.
    });

    it("fourth", function (done) {
        console.log("fourth: do nothing");
        done();
    });
});

Then execute it with:

mocha -R spec test.js

You will not see the fourth test start until:

1. The first and second tests are finished.
2. The third tests has timed out.

Now, run it with:

mocha -R spec --bail test.js

Mocha will stop as soon as test 3 fails.

Answer 2

if your tests are set up properly, only testing a small piece of business logic then you can run your tests asynchronously but they should not hold up other tests. the way to get a test to complete is to do the following:

describe("BBController", function() {
    it("should save", function(done) {
       // handle logic
       // handle assertion or other test
       done(); //let mocha know test is complete - results are added to test list
    });
    it("should delete", function(done) {
       // handle logic
       // handle assertion or other test
       done(); //let mocha know test is complete - results are added to test list
    });
});

again, no test should need to wait for another test to run to pass, if you have this issue then you should look at ways to impove your dependency injection or prep your tests with a before method