编辑“︁Template:Testcase/doc”︁（章节）

=== Usage ===
Use to compare a template with its sandbox.  Pass the raw code in nowikis as the first unnamed parameter; the existing template as the second, and the sandbox as the third.  The optional named parameter {{para|id}} is used as a heading (to describe the test being performed); if {{para|id}} is omitted, parameter 1 is used. The optional named parameter {{para|layout}} determines whether the live and sandbox outputs are displayed side by side or on top of each other. The default value is vertical (on top of each other). A value of horizontal will produce side by side output.

If the pair of test codes in parameters 2 and 3 both produce the same output, then the test case is displayed in a collapsed table with a green heading.  If the test codes produce different output ''(this includes white space differences)'', then the test is displayed in an uncollapsed table with a yellow heading.

Note that some more complex templates may cause testcases to be highlighted even when their output is the same. The cause of this is under investigation...