Help:Testing

Before committing to a change, one should test it first.

Changes to a page
There is a "Show preview" button near the submit button. One should check to make sure that the links are correct and the spelling is correct.

Spelling
Linuxquestions.org appears to have a spelling checker in their modified version of MediaWiki. Also, one can use Konqueror or Firefox with a spelling check extension to check to spell within the browser window. Note that this does not work when using syntax highlighting.

Testing features of existing software on one of the regular projects
This applies anyway for tests that depend on settings which are different per project, such as:
 * interlanguage links (software feature)
 * case-sensitivity of the first character
 * character encoding
 * enabling of embedding images in other projects and images outside Wikimedia
 * MediaWiki:Monobook.css, etc.
 * tests depending on other content, such as templates, images
 * tests depending on project-specific variables such as namespace prefixes

It can be done:
 * in special pages such as Draft:Sandbox
 * on user pages and subpages
 * using Preview. This cannot be used to test how a change in a page affects another page, such as when changing a template; to test automatic conversion of wikitext, the new wikitext can be seen pressing "Show changes". Automatic conversion of special characters to their decimal numeric codes is seen in the edit box.

A test involving the variable, e.g. a link to an image or another page with a name containing  , can be done on the Talk page since the value of the variable is the same on that page.

Sysops testing the available links and how things work for ordinary logged-in users can log in under another name, or in a project for which they are not a sysop.

Test Wikipedia
An advantage of the test Wikipedia is that is does not interfere with or clutter the regular projects. The project may be reset or history may otherwise be lost, so one has to save elsewhere what one wants to keep.