caption: testcase
created: 20230406161341763
modified: 20230406161341763
tags: Widgets
title: TestCaseWidget
type: text/vnd.tiddlywiki

! Introduction

The testcase widget creates an independent subwiki loaded with the specified payload tiddlers and then renders a specified template from within the subwiki.The default template displays a split view with the source tiddlers on the left and the rendered tiddler titled `Output` on the right. It also displays the tiddler titled `Description` as the heading. This makes it possible to run independent tests that also serve as documentation examples.

! Content and Attributes

The content of the `<$testcase>` widget is not displayed but instead is scanned for <<.wlink DataWidget>> widgets that define the payload tiddlers to be included in the test case.

|!Attribute |!Description |
|<<.attr template>> |Optional title of the template used to display the testcase (defaults to $:/core/ui/testcases/DefaultTemplate) |

! Payload Tiddlers

The payload tiddlers are the tiddler values that are loaded into the subwiki that is created to run the tests. They are created via <<.wlink DataWidget>> widgets within the body of the `<$testcase>` widget.

! State Handling

The `<$testcase>` widget sets the variable `transclusion` to a hash that reflects the names and values of all the payload tiddlers. This makes it easier for test case templates to create unique state tiddler titles using the [[qualify Macro]] or QualifyWidget.

! Test Case Conventions

The following conventions are used for test case tiddlers:

* `Description` contains a brief description of the test (rendered in inline mode)
* `Output` contains the tiddler text to be rendered. It can also reference other tiddlers
* `ExpectedResult` contains the HTML that should match the rendering of the tiddler `Output`

! Example

<$testcase>
<$data $tiddler="$:/core/ui/testcases/DefaultTemplate"/>
<$data $tiddler="$:/core/ui/testcases/DefaultTemplate/Source"/>
<$data title="Description" text="Simple example of a test case"/>
<$data title="Output" text="""<$testcase>
<$data title="Description" text="How to calculate 2 plus 2"/>
<$data title="Output" text="<$text text={{{ =2 =[add[2]] }}}/>"/>
</$testcase>
"""/>
</$testcase>