# Lintpref

The lintpref linter is a simple linter for libpref files to check for duplicate
entries between {searchfox}`modules/libpref/init/all.js` and
{searchfox}`modules/libpref/init/StaticPrefList.yaml`. If a duplicate is found,
lintpref will raise an error and emit the `all.js` line where you can find
the duplicate entry.

## Running Locally

The linter can be run using mach:

```{eval-rst}
.. parsed-literal::

    $ mach lint --linter lintpref

```

## Fixing Lintpref Errors

In most cases, duplicate entries should be avoided and the duplicate removed
from `all.js`. If for any reason a pref should exist in both files, the pref
should be added to `IGNORE_PREFS` in {searchfox}`tools/lint/libpref/__init__.py`.

## Sources

- {searchfox}`Configuration (YAML) <tools/lint/lintpref.yml>`
- {searchfox}`Source <tools/lint/libpref/__init__.py>`