Editing Module:UnitTests/doc

UnitTests provides a unit test facility that can be used by other scripts using '''require'''. See [[Wikipedia:Lua#Unit_testing]] for details. The following is a sample from [[Module:Example/testcases]]:

{{#tag:syntaxhighlight|
-- Unit tests for [[Module:Example]]. Click talk page to run tests.
local p = require('Module:UnitTests')

function p:test_hello()
    self:preprocess_equals('<nowiki>{{#invoke:Example | hello}}</nowiki>', 'Hello World!')
end

return p
|lang="lua"}}

The talk page [[Module talk:Example/testcases]] executes it with <code><nowiki>{{#invoke: Example/testcases | run_tests}}</nowiki></code>. Test methods like test_hello above '''must begin with''' "'''test'''".

== Methods ==
=== run_tests ===
* {{code|1=run_tests}}: Runs all tests. Normally used on talk page of unit tests. <syntaxhighlight lang="wikitext">
{{#invoke:Example/testcases|run_tests}}
</syntaxhighlight>
* If {{code|1=differs_at}} is specified, a column will be added showing the first character position where the expected and actual results differ. <syntaxhighlight lang="wikitext">
{{#invoke:Example/testcases|run_tests|differs_at=1}}
</syntaxhighlight>
* If {{code|1=highlight}} is specified, failed tests will be highlighted to make them easier to spot. A [[WP:USERSCRIPT|user script]] that [[User:Fred_Gandt/moveFailedModuleTestsToTop.js|moves failed tests to the top]] is also available. <syntaxhighlight lang="wikitext">
{{#invoke:Example/testcases|run_tests|highlight=1}}
</syntaxhighlight>
* If {{code|1=live_sandbox}} is specified, the header will show the columns "Test", "Live", "Sandbox", "Expected". This is required when using the {{code|1=preprocess_equals_sandbox_many}} method.

=== preprocess_equals ===
* {{code|1=preprocess_equals(text, expected, options)}}: 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. <syntaxhighlight lang="lua">
self:preprocess_equals('{{#invoke:Example | hello}}', 'Hello, world!', {nowiki=1})
</syntaxhighlight>

=== preprocess_equals_many ===
* {{code|1=preprocess_equals_many(prefix, suffix, cases, options)}}: Performs a series of preprocess_equals() calls on a set of given pairs. Automatically adds the given prefix and suffix to each text. <syntaxhighlight lang="lua">
self:preprocess_equals_many('{{#invoke:Example | hello_to |', '}}', {
    {'John', 'Hello, John!'},
    {'Jane', 'Hello, Jane!'},
}, {nowiki=1})
</syntaxhighlight>

=== preprocess_equals_preprocess ===
* {{code|1=preprocess_equals_preprocess(text, expected, options)}}: Gives two pieces of wikitext to preprocess and determines if they produce the same value. Useful for comparing scripts to existing templates. <syntaxhighlight lang="lua">
self:preprocess_equals_preprocess('{{#invoke:Example | hello}}', '{{Hello}}', {nowiki=1})
</syntaxhighlight>

=== preprocess_equals_preprocess_many ===
* {{code|1=preprocess_equals_preprocess_many(prefix1, suffix1, prefix2, suffix2, cases, options)}}: 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. <syntaxhighlight lang="lua">
self:preprocess_equals_preprocess_many('{{#invoke:ConvertNumeric | numeral_to_english|', '}}', '{{spellnum', '}}', {
    {'2'}, -- equivalent to {'2','2'},
    {'-2', '-2.0'},
}, {nowiki=1})
</syntaxhighlight>

=== preprocess_equals_sandbox_many ===
* {{code|1=preprocess_equals_sandbox_many(module, function, cases, options)}}: Performs a series of preprocess_equals_compare() calls on a set of given pairs. The test compares the live version of the module vs the /sandbox version and vs an expected result. Ensure live_sandbox is specified or there may be some errors in the output. <syntaxhighlight lang="lua">
self:preprocess_equals_sandbox_many('{{#invoke:Example', 'hello_to', {
    {'John', 'Hello, John!'},
    {'Jane', 'Hello, Jane!'},
}, {nowiki=1})
</syntaxhighlight>

=== equals ===
* {{code|1=equals(name, actual, expected, options)}}: 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. <syntaxhighlight lang="lua">
self:equals('Simple addition', 2 + 2, 4, {nowiki=1})
</syntaxhighlight>

=== equals_deep ===
* {{code|1=equals_deep(name, actual, expected, options)}}: 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. <syntaxhighlight lang="lua">
self:equals_deep('Table comparison', createRange(1,3), {1,2,3}, {nowiki=1})
</syntaxhighlight>

== Test options ==
These are the valid options that can be passed into the options parameters of the test functions listed above.

=== nowiki ===
Enabling this wraps the output text in {{tag|nowiki}} tags to avoid the text being rendered (E.g. <nowiki><span>[[Example|Page]]</span></nowiki> instead of <span>[[Example|Page]]</span>)

=== combined ===
{{hatnote|Only available in <code>preprocess_equals</code> and <code>preprocess_equals_preprocess</code>}}
Enabling this will display the output text in both the rendered mode and the nowiki mode to allow for both a raw text and visual comparison.

=== templatestyles ===
{{hatnote|Only available in <code>preprocess_equals</code> and <code>preprocess_equals_preprocess</code>}}
Enabling this fixes the IDs in the [[mw:Strip marker|strip markers]] {{tag|templatestyles}} produces when processed to avoid incorrectly failing the tests.

=== stripmarker ===
{{hatnote|Only available in <code>preprocess_equals</code> and <code>preprocess_equals_preprocess</code>}}
Enabling this fixes the IDs in ''all'' strip markers produces when processed to avoid incorrectly failing the tests.

=== display ===
{{hatnote|Only available in <code>equals</code>}}
An optional function that changes how the output from the tests are displayed. This doesn't effect the comparison process.

== See also ==
* [[Module:ScribuntoUnit]] – alternative unit test module

<includeonly>{{#ifeq:{{SUBPAGENAME}}|sandbox||
<!-- Categories go here and interwikis go in Wikidata. -->
[[Category:Modules for test tools]]
[[Category:Modules that check for strip markers]]
}}</includeonly>