How to specify test directory for mocha?

Question

Use this:

mocha server-test

Or if you have subdirectories use this:

mocha "server-test/**/*.js"

Note the use of double quotes. If you omit them you may not be able to run tests in subdirectories.

Edit : This option is deprecated : https://mochajs.org/#mochaopts

---

If you want to do it by still just running mocha on the command line, but wanted to run the tests in a folder ./server-tests instead of ./test, create a file at ./test/mocha.opts with just this in the file:

server-tests

If you wanted to run everything in that folder and subdirectories, put this into test/mocha.opts

server-tests
--recursive

mocha.opts are the arguments passed in via the command line, so making the first line just the directory you want to change the tests too will redirect from ./test/

Here's one way, if you have subfolders in your test folder e.g.

/test
/test/server-test
/test/other-test

Then in linux you can use the find command to list all *.js files recursively and pass it to mocha:

mocha $(find test -name '*.js')

The nice way to do this is to add a "test" npm script in package.json that calls mocha with the right arguments. This way your package.json also describes your test structure. It also avoids all these cross-platform issues in the other answers (double vs single quotes, "find", etc.)

To have mocha run all js files in the "test" directory:

"scripts": {
    "start": "node ./bin/www", -- not required for tests, just here for context
    "test": "mocha test/**/*.js"
  },

Then to run only the smoke tests call:

npm test

You can standardize the running of all tests in all projects this way, so when a new developer starts on your project or another, they know "npm test" will run the tests. There is good historical precedence for this (Maven, for example, most old school "make" projects too). It sure helps CI when all projects have the same test command.

Similarly, you might have a subset of faster "smoke" tests that you might want mocha to run:

"scripts": {
    "test": "mocha test/**/*.js"
    "smoketest": "mocha smoketest/**/*.js"
  },

Then to run only the smoke tests call:

npm smoketest

Another common pattern is to place your tests in the same directory as the source that they test, but call the test files *.spec.js. For example: src/foo/foo.js is tested by src/foo/foo.spec.js.

To run all the tests named *.spec.js by convention:

  "scripts": {
    "test": "mocha **/*.spec.js"
  },

Then to run all the tests call:

npm test

See the pattern here? Good. :) Consistency defeats mura.

Don't use the -g or --grep option, that pattern operates on the name of the test inside of it(), not the filesystem. The current documentation is misleading and/or outright wrong concerning this. To limit the entire command to a portion of the filesystem, you can pass a pattern as the last argument (its not a flag).

For example, this command will set your reporter to spec but will only test js files immediately inside of the server-test directory:

mocha --reporter spec server-test/*.js

This command will do the same as above, plus it will only run the test cases where the it() string/definition of a test begins with "Fnord:":

mocha --reporter spec --grep "Fnord:" server-test/*.js