By default, mocha looks for files in the test directory:

$ tree
.
0 directories, 0 files

$ mocha
Error: cannot resolve path (or pattern) 'test'

If you have files in subdirectories of test, you’ll need to pass the recursive flag:

$ mocha --recursive

What if you want to specify tests in a different directory?

You can pass the directory as a CLI argument:

$ mocha another/directory

Glob

Now what if you want to match files like test/foo.spec.js and test/bar.spec.js?

Easy! Use a glob expression:

$ mocha "./test/*.spec.js"

And if you need to recurse through all nested directories:

$ mocha "./test/**/*.spec.js"

But what if you want to match all files in test except for exclude.js?

You’ll need to negate the filename in the pattern:

$ mocha "./test/**/!(exclude).js"

Finally, if you need to ignore node_modules and match files like baz.spec.js and qux.spec.js in the project root:

$ mocha "./{,!(node_modules)/**/}*.spec.js"

For more information on globs, check out glob-primer.