Ensure - Easy testing with node.js and vows

I've been using vows (and enjoying it) lately. However I never did any behavior driven development, so all that building a JSON document with phrase thing didn't really mean much to me.

All I needed from a test framework was to have my tests described in a way that contributors and maintainers can understand the test as easily as possible. I came up with something like this:

  var ensure = require('ensure')
    , assert = require('assert')
    , tests = exports
    ;

  // your test code, callback is sent to testname_ok
  tests.foo = function (callback) {
    callback(true);
  };

  // the callback you will eventually fire
  tests.foo_ok = function (t) {
    assert.ok(t);
  };

  ensure('foo', tests, module);

This was the idea for ensure - vows without all the other stuff I didn't care about. ensure is simply twelve lines of code that will translate something like this code snippet into something that vows can run. You can install ensure with npm npm install ensure.

You define a test on a property and give it a name. Then the convention is the callback will be in name_ok. e.g. If you have test foo the callback will be foo_ok. That's it.

Another pattern I identified was constantly commenting other tests to when I needed to isolate and run a single test. This is cumbersome and causes some faulty commits.

I had the same problem in ensure so decided to tackle it. When calling ensure you can pass a comma separated argument which says which tests you want to run (by default ensure runs all tests). So if I want to execute tests in foo.js named bar and baz I would:

  # this will only run tests bar and baz
  node foo.js bar,baz

This is super useful, e.g. in nanocouch I frequently want to see verbose output of a single test. I can achieve that by simply:

  NANO_ENV=testing node tests/att/get.js att_get

Which would run the att_get test with verbose output. If you are curious about how real life tests would look like you can look at nuvem (MarkLogic node.js client).