Running test cases selectively with Mocha

Question

There is a total of 20 test case files. I want to test a particular set of 10 test cases. Is there any script file or any other method to run the test cases selectively with Mocha?

Answer 1

There are two principal ways to specify a subset of tests to run:

1. You can give Mocha the name of the file that contains the tests you want to run:

   $ mocha path/to/file
   

   It is possible to give paths to multiple files if needed. For instance, if you have 10 test files and want to run all the tests from only 2 of them, you could give the paths of the 2 files.

   This method relies on you splitting your tests into separate files according to a logic that suits your situation.

2. You can use the --grep option:

   $ mocha --grep pattern
   

   The pattern is a regular expression that Mocha will use to test each test title. Each test for which the pattern matches will be run.

The two methods could be combined to run only tests that match a pattern and that are from one specific file: $ mocha --grep pattern path/to/file

Answer 2

mocha.describe("test1", () => {
    mocha.it("test1_1", (done) => {
        done();
    })
    mocha.it.only("test1_2", (done) => {
      done();
    })
})
OutPut : 
 test2
✔ test2_2 //because of it.only

Answer 3

Following command works for me

$ node_modules/.bin/mocha test/file1.js test/file2.js