Presubmit checks

Chromium has a system of presubmit checks which contains a lot of Chromium-specific validators we can use. The system is greatly explained here: https://www.chromium.org/developers/how-tos/depottools/presubmit-scripts/

Presubmit checks in Brave

To run presubmits in Brave: npm run presubmit, the result will be printed to the console.

There're few options you may find useful:

--base <base branch>  set the destination branch for the PR
--all                 run presubmit on all files
--files <file list>   semicolon-separated list of files to run presubmit on
--verbose [arg]       pass --verbose 2 for more debugging info
--fix                 try to fix found issues automatically

If you need to configure some upstream checks, i.e. disable or add a file filter, please use: chromium_presubmit_config.json5.

When to run presubmit checks

Please run presubmit checks locally before pushing changes to PR. ERRORS must be fixed, Warnings should be fixed if you can. Messages usually highlight something to be aware of, so please read them.

Presubmit checks are also run by CI for every PR. ERRORS will block PR merge, Warnings will appear in PR's comments and reviewer most likey will ask you to fix them.

Available checks

Brave checks

license header check

Chromium checks

In addition to manually written checks, the presubmit system also runs:

code format (clang-format, yapf)
cpplint
pylint
checkdeps
eslint

It can be extended to support other checks, such as chromium_src macro validation.

The system also supports Android style check, but it's currently disabled via config file, because most .java files require style rework.

Chromium modifications

Currently upstream checks are modified in such way:

Make it compatible with our directory structure.
Disable Gerrit-specific checks.
Disable OWNERS/AUTHORS checks.
Add ability to fully disable a check or filter some files.
Force some checks to trigger errors instead of warnings.

Under the hood we run git cl presubmit in src/brave directory, which runs all checks from src/brave/**/PRESUBMIT.py and upstream checks from src/PRESUBMIT.py.

src/PRESUBMIT.py is modified using chromium_presubmit_overrides.py to support chromium_presubmit_config.json5.

Presubmit checks