Skip to content
Validator for
Python Other
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.

README.rst Validator

Version 1.0

This validator is a proposed replacement for the current add-on validator available at It is written entirely in python.


Python Libraries:

  • rdflib
  • cssutils

Python Libraries for Testing:

  • nose
  • coverage


Run the validator as follows:

python <path to xpi> [-t <expected type>] [-o <output type>] [-v] [--file <output file>] [--boring]

The path to the XPI should point to an XPI file.

Expected Type:

The expected type should be one of the following values:

any (default)
Accepts any extension
Accepts only extensions
Accepts only themes
Accepts only dictionaries
Accepts only language packs
Accepts only OpenSearch XML files (unpackaged)
Accepts only multi-item XPI packages

Specifying an expected type will throw an error if the validator does not detect that particular type when scanning. All addon type detection mechanisms are used to make this determination.

Output Type:

The output type may be either of the following:

text (default)
Outputs a textual summary of the addo-on analysis. Supports verbose mode.
Outputs a JSON snippet representing a full summary of the add-on analysis.

Verbose Mode:

If the "-v" flag is set, the output will include informational messages in addition to errors and warnings. Informational messages contain information about the analysis that do not invalidate the add-on, but are contextually relevant.

Verbose mode will also output detailed descriptions of each summary item, as well as the file path and line number (if available).

This mode is only supported by certain output types. Output types that do not support verbose mode will output informational messages by default.

Output File:

Specifying an output file with the "--file" flag captures the output of the analysis and stores it to the file specified. Specifying this option will not produce any output to the command line.

When outputting to a file, Boring Mode is automatically activated.

Boring Mode:

Boring mode, when activated, doesn't print colors to the terminal.


Text Output Mode:

In text output mode ("text"), output is structured in the format of one message per line. The messages are prefixed by their priority level (i.e.: "Warning: This is the message").

At the head of the text output is a block describing what the add-on type was determined to be.

JSON Output Mode:

In JSON output mode ("json"), output is formatted as a JSON snippet containing all messages. The format for the JSON output is that of the sample document below.

        "detected_type": "extension",
        "success": false,
        "messages": [
                        "type": "error",
                        "message": "This is the error message text.",
                        "description": "Description of the error message.",
                        "file": "",
                        "line": 0
                        "type": "warning",
                        "message": "This is the warning message text.",
                        "description": "Description of the warning message.",
                        "file": "testfile.xml",
                        "line": 0
                        "type": "info",
                        "message": "This is the informational message text.",
                        "description": "Description of the info message."
                        "file": "chrome.manifest",
                        "line": 21
                        "type": "error",
                        "message": "test.xpi > An error was found.",
                        "description": "This error happened within a subpackage."
                        "file": [
                        "line": 21

JSON Notes:

When a subpackage exists, an angle bracket will delimit the subpackage name and the message text.

If no applicable file is available (i.e.: when a file is missing), the file value will be empty. If a file value is available within a subpackage, then the file attribute will be a list containing the name of the outermost subpackage's name, followed by each successive concentric subpackage's name, followed by the name of the file that the message was generated in. If no applicable file is available within a subpackage, the file attribute is identical, except the last element of the list in the file attribute is an empty string.

For instance, this tree would generate the following messages:

        |  |
        |  |-subsubpackage.xpi
        |     |
        |     |-chrome.manifest
        |     |-install.rdf
        "type": "info",
        "message": "<em:type> not found in install.rdf",
        "description": " ... ",
        "file": "install.rdf",
        "line": 0
        "type": "error",
        "message": "Invalid chrome.manifest subject: override",
        "description": " ... ",
        "file": "chrome.manifest",
        "line": 7
        "type": "error",
        "message": "subpackage.xpi > install.rdf missing from theme",
        "description": " ... ",
        "file": ["subpackage.xpi", ""],
        "line": 0
        "type": "error",
        "message": "subpackage.xpi > subsubpackage.xpi > Invalid chrome.manifest subject: sytle",
        "description": " ... ",
        "file": ["subpackage.xpi", "subsubpackage.xpi", "chrome.manifest"],
        "line": 5


Unit tests can be run with a simple call to:


However, to turn run unit tests with code coverage, the appropriate command would be:

nosetests --with-coverage --cover-package=validator --cover-skip=validator.argparse,validator.outputhandlers. --cover-inclusive --cover-tests

Note that in order to use the --cover-skip nose parameter, you must install the included patch for nose's plugin:

Something went wrong with that request. Please try again.