Features and Tests

There are many tests that take place during the validation process. Each exists in a tier, which groups similar tests together. Similar tests are defined as tests which generate errors of similar priority and type.

Tiers

Tier 1

• install.rdf tests
  • Test for banned elements
  • Test for appropriate elements based on type
  • Valid values (ID, version, name/trademark)
• Conduit Toolbar detection
• Common library blacklisting
• Package Layout
  • Dictionary, language pack, theme layout inspection
  • Blacklisted file types
• Target Application inspection

Tier 2

• Content inspection tests
  • JAR inspection
  • Nested extension inspection
  • Markup inspection (HTML, XHTML, XML, XUL
  • CSS inspection
  • Language Pack HTML inspection
• Language pack manifest inspection
• Theme manifest inspection
• XPCOM detection

Tier 3

• Regex tests (pattern matching)
• Basic syntax and reference checking

The validator prevents:

• Modification of variables declared as const
• Modification of global variables and entities
• Modification of main type prototypes (Array.prototype, Object.prototype, etc.)
• Access to banned entities and functions (eval, Function, etc.)
• setAttribute to modify event handlers
• innerHTML to set event handlers
• innerHTML to generate banned markup
• innerHTML to execute malicious scripts
• Use of createElement and createElementNS to create script tags
• Synchronous use of XMLHttpRequest

Tier 4

• L10n Completeness
  • L10n character encoding inspection

Tier 5

While the validator treats tier 5 as standard tier, it is in many ways a "virtual" tier. Messages for this tier are generated during tiers 1-4, however, these messages may be discarded if determined mode is not enabled and a failure occurs before tier 5 is run.

• Compatibility tests
  • Firefox 5 compatibility
  • Firefox 6 compatibility
  • Firefox 7 compatibility