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utest

The minimal unit testing library.

utest

The minimal unit testing library.

I wanted something simple, that just does unit tests (no async) and where each test is a standalone UNIX program. Now it exists.

Currently there is only one sane way: Do not use a framework. Instead use one file per test.

If that becomes an issue, you should write more unit tests. (It is not a unit test if it does I/O).

npm install utest

Running a test with utest is very simple:

var test   = require('utest');
var assert = require('assert');
 
test('Number#toFixed', {
  'returns a string': function() {
    assert.equal(typeof (5).toFixed(), 'string');
  },
 
  'takes number of decimal places': function() {
    assert.equal((5).toFixed(1), '5.0');
  },
 
  'does not round': function() {
    assert.equal((5.55).toFixed(1), '5.5');
  },
});

It is also possible to define a before/after method:

var test   = require('utest');
var assert = require('assert');
 
test('Date', {
  before: function() {
    this.date = new Date;
  },
 
  after: function() {
    this.date = null;
  },
 
  'lets you manipulate the year': function() {
    this.date.setYear(2012);
    assert.equal(this.date.getFullYear(), 2012);
  },
 
  'can be coerced into a number': function() {
    assert.equal(typeof +this.date, 'number');
  },
});

Last but not least, you can run individual tests by prefixing them with an exclamation mark. This is useful when putting debug statements into the subject under test:

var test   = require('utest');
var assert = require('assert');
 
test('MyTest', {
  '!will be executed': function() {
    // ... 
  },
 
  'will not be exectuted': function() {
    // ... 
  },
});

I want to keep this library as minimal as possible, but I do consider the addition of the following features:

  • Nested test cases
  • TAP output (if TAP=1 in the environment, switch to TapReporter class)
  • Leak detection (automatically add a final test that fails if there are global leaks).

This module is licensed under the MIT license.