UnitTests provides a unit test facility that can be used by other scripts using require().

Following is a sample from Module:Hello/test:

-- Unit tests for [[Module:Hello]]. Click test page to run tests.
local p = require('Module:UnitTests')
 
function p:test_hello()
    self:preprocess_equals('{{#invoke:Hello | hello}}', 'Hello, world!')
end
 
return p

The test page Wikipedia:Lua/Modul/UnitTests/test executes it with:

{{#invoke: Bananas/test | run_tests}}

Test methods like test_hello above must begin with "test".

run_tests(differs_at)

Runs all tests. If "differs_at=1" is specified, a column will be added showing the first character position where the expected and actual results differ. Normally used on talk page of unit tests.

    {{#invoke:Hello/test|run_tests}}

preprocess_equals(text, expected)

Gives a piece of wikitext to preprocess and an expected resulting value. Scripts and templates can be invoked in the same manner they would be in a page.

    self:preprocess_equals('{{#invoke:Hello | hello}}', 'Hello, world!')

preprocess_equals_many(prefix, suffix, cases)

Performs a series of preprocess_equals() calls on a set of given pairs. Automatically adds the given prefix and suffix to each text.

    self:preprocess_equals_many('{{#invoke:DemoArgs | add |', '}}', {
        {'2|3', '5'},
        {'-2|2', '0'},
    })

preprocess_equals_preprocess(text, expected)

Gives two pieces of wikitext to preprocess and determines if they produce the same value. Useful for comparing scripts to existing templates.

    self:preprocess_equals_preprocess('{{#invoke:Hello | hello}}', '{{Hello}}')

preprocess_equals_preprocess_many(prefix, suffix, cases)

Performs a series of preprocess_equals_preprocess() calls on a set of given pairs. The prefix/suffix supplied for both arguments is added automatically. If in any case the second part is not specified, the first part will be used.

    self:preprocess_equals_preprocess_many('{{#invoke:Foo | spellnum |', '}}', '{{spellnum', '}}', {
        {'2'}, -- equivalent to {'2','2'},
        {'-2', '-2.0'},
    })

equals(name, actual, expected)

Gives a computed value and the expected value, and checks if they are equal according to the == operator. Useful for testing modules that are designed to be used by other modules rather than using #invoke.

    self:equals('Simple addition', 2 + 2, 4)

equals_deep(name, actual, expected)

Like equals, but handles tables by doing a deep comparison. Neither value should contain circular references, as they are not handled by the current implementation and may result in an infinite loop.

    self:equals_deep('Table comparison', createRange(1,3), {1,2,3})

en:Module:UnitTests 2013-05-18