.. _testing-query-help-files:

Testing query help files
========================

Test query help files by rendering them as markdown to ensure they are valid 
before uploading them to the CodeQL repository or using them in code scanning.

Query help is documentation that accompanies a query to explain how the query works,
as well as providing information about the potential problem that the query identifies.
It is good practice to write query help for all new queries. For more information,
see `Contributing to CodeQL <https://github.com/github/codeql/blob/main/CONTRIBUTING.md>`__
in the CodeQL repository.

The CodeQL CLI includes a command to test query help and render the content as 
markdown, so that you can easily preview the content in your IDE. Use the command to validate 
query help files before uploading them to the CodeQL repository or sharing them with other users. 

Prerequisites
-------------

- The query help (``.qhelp``) file must have an accompanying query (``.ql``) file with 
  an identical base name.
- The query help file should follow the standard structure and style for query help documentation.
  For more information, see the `Query help style guide <https://github.com/github/codeql/blob/main/docs/query-help-style-guide.md>`__ 
  in the CodeQL repository. 

Running ``codeql generate query-help``
--------------------------------------

You can test query help files by running the following command::

   codeql generate query-help <qhelp|query|dir|suite> --format=<format> [--output=<dir|file>] 

where ``<qhelp|query|dir|suite>`` is one of:

- the path to a ``.qhelp`` file.
- the path to a ``.ql`` file.
- the path to a directory containing queries and query help files.
- the path to a query suite, or the name of a well-known query suite for a QL pack. 
  For more information, see "`Creating CodeQL query suites <creating-codeql-query-suites.html#specifying-well-known-query-suites>`__."

You must specify a ``--format`` option, which defines how the query help is rendered. 
Currently, you must specify ``markdown`` to render the query help as markdown. 

The ``--output`` option defines a file path where the rendered query help will be saved.

- For directories containing ``.qhelp`` files or a query suites 
  defining one or more ``.qhelp`` files, you must specify an ``--output`` directory. 
  Filenames within the output directory will be derived from the ``.qhelp`` file names. 

- For single ``.qhelp`` or ``.ql`` files, you may specify an ``--output`` option.
  If you don't specify an output path, the rendered query help is written to ``stdout``.

For full details of all the options you can use when testing query help files,
see the `generate query-help reference documentation
<../manual/generate-query-help>`__.

Results
-------

When you run the command, CodeQL attempts to render  
each ``.qhelp`` file that has an accompanying ``.ql`` file. For single files, the rendered
content will be printed to ``stdout`` if you don't specify an ``--output`` option. For all other 
use cases, the rendered content is saved to the specified output path. 

By default, the CodeQL CLI will print a warning message if:

- Any of the query help is invalid, along with a description of the invalid query help elements
- Any ``.qhelp`` files specified in the command don't have the same base name 
  as an accompanying ``.ql`` file
- Any ``.ql`` files specified in the command don't have the same base name
  as an accompanying ``.qhelp`` file

You can tell the CodeQL CLI how to handle these warnings by including a ``--warnings`` option in your command.
For more information, see the `generate query-help reference documentation <../manual/generate-query-help#cmdoption-codeql-generate-query-help-warnings>`__.

Further reading
---------------

- ":ref:`Query help files <query-help-files>`"
