mocha-tags

mocha-tags

• Do you have integration tests that connect to your internal network?
• Do you need to skip them when running on Travis?
• Or do you want to tag "slow" and "fast" tests, and run them separately?

npm install mocha-tags --save-dev

Quick example

tags('network')
.describe(/* ... */)

tags('integration', 'fast')
.it(/* ... */)

By default all tests will run as usual, but you can use the --tags option to filter them:

mocha --tags "is:integration not:slow not:network"

Tests that don't match the criteria are skipped with the xdescribe or xit commands, and appear as pending in the test output.

Filtering

Note: because of the way filtering works, tags have to be a single word, without any spaces.

is:<tag>

Run tests with the X tag

mocha --tags "is:X"

Run tests with the X or Y tags

mocha --tags "is:X is:Y"

Run tests with the X and Y tag

mocha --tags "is:X+Y"

not:<tag>

Don't run tests with the X flag

mocha --tags "not:X"

Don't run tests with the X or Y flag

mocha --tags "not:X not:Y"

Don't run tests with the X and Y flag

mocha --tags "not:X+Y"

Programmatic usage

You might want to exclude certain tags based on complex logic. This is not easy to define from the command line, so mocha-tags exposes its filter programmatically.

var tags = require('mocha-tags');

// either replace the entire filter
tags.filter = new tags.Filter('not:trading-hours');

// or simply modify the existing one
if (moment().hours() < 8 || moment().hours() > 18) {
  tags.filter.remove('not:unit');
  tags.filter.add('not:trading-hours');
}

tags('trading-hours').it(
  // some integration test than can only run during core hours
);

Troubleshooting

Skipped tests appear as pending in the test output, so you should always notice any test that was skipped by accident.

It also helps to add the following at the top of your main test file / spec helper.

var tags = require('mocha-tags');
console.log('Test filter: ', tags.filter);

Custom test hooks

mocha-tags supports the following keywords:

• tags().describe : normal usage
• tags().describe.only : ignores any tags and filters, and runs by itself
• tags().xdescribe : ignored regardless of tags

...and the same pattern for it. You can also add custom test hooks by setting the following property:

tags.hooks = function(either) {
  this.mytest = either(fnMatch, fnSkip);
};

// to be used as
tags('hello', 'world').mytest(/* arguments */);

// which will call either
fnMatch(/* arguments */);
fnSkip(/* arguments */);