mongodb/docs/linting.md

Linting in the MongoDB codebase

C++ Linters

clang-format

The buildscripts/clang_format.py wrapper script runs the clang-format linter. You can see the usage message for the wrapper by running buildscripts/clang_format.py --help.

Ex: buildscripts/clang_format.py lint

Linter	Configuration File(s)	Help Command	Documentation
clang-format	.clang-format	clang-format --help	https://clang.llvm.org/docs/ClangFormat.html

clang-tidy

The evergreen/run_clang_tidy.sh shell script runs the clang-tidy linter. In order to run clang-tidy you must have a compilation database (compile_commands.json file).

Ex: bash buildscripts/run_clang_tidy.sh

Linter	Configuration File(s)	Help Command	Documentation
clang-tidy	.clang-tidy	clang-tidy --help	https://clang.llvm.org/extra/clang-tidy/index.html

errorcodes.py

The buildscripts/errorcodes.py script runs a custom error code linter, which verifies that all assertion codes are distinct. You can see the usage by running the following command: buildscripts/errorcodes.py --help.

Ex: buildscripts/errorcodes.py

quickcpplint.py

The buildscripts/quickcpplint.py script runs a simple MongoDB C++ linter. You can see the usage by running the following command: buildscripts/quickcpplint.py --help. You can take a look at buildscripts/linter/simplecpplint.py to better understand the rules for this linter.

Ex: buildscripts/quickcpplint.py lint

Javascript Linters

The buildscripts/eslint.py wrapper script runs the eslint javascript linter. You can see the usage message for the wrapper by running buildscripts/eslint.py --help.

Ex: buildscripts/eslint.py lint

Linter	Configuration File(s)	Help Command	Documentation
eslint	.eslintrc.yml .eslintignore	eslint --help	https://eslint.org/

Yaml Linters

The buildscripts/yamllinters.sh shell script runs the yaml linters. The supported yaml linters are: yamllint & evergreen-lint. evergreen-lint is a custom MongoDB linter used specifically for evergreen yaml files.

Ex: bash buildscripts/yamllinters.sh

Linter	Configuration File(s)	Help Command	Documentation
yamllint	etc/yamllint_config.yml	yamllint --help	https://readthedocs.org/projects/yamllint/
evergreen-lint	etc/evergreen_lint.yml	python -m evergreen_lint --help	https://github.com/evergreen-ci/config-linter

Python Linters

The buildscripts/pylinters.py wrapper script runs the Python linters. You can see the usage message for the wrapper by running the following command: buildscripts/pylinters.py --help. The following linters are supported: pylint, mypy, pydocstyle & yapf.

Ex: buildscripts/pylinters.py lint

Linter	Configuration File(s)	Help Command	Documentation
pylint	.pylintrc	pylint --help	https://www.pylint.org/
mypy	.mypy.ini	mypy --help	https://readthedocs.org/projects/mypy/
pydocstyle	.pydocstyle	pydocstyle --help	https://readthedocs.org/projects/pydocstyle/
yapf	.style.yapf	yapf --help	https://github.com/google/yapf

SCons Linters

buildscripts/pylinters.py has the lint-scons and fix-scons commands to lint and fix SCons and build system related code. Currently yapf is the only linter supported for SCons code.

Using SCons for linting

You can use SCons to run most of the linters listed above via their corresponding Python wrapper script. SCons also provides the ability to run multiple linters in a single command. At this time, SCons does not support clang-tidy or buildscripts/yamllinters.sh

Here are some examples:

SCons Target	Linter(s)	Example
lint	clang-format errorcodes.py quickcpplint.py eslint pylint mypy pydocstyle yapf	buildscripts/scons.py lint
lint-fast	clang-format errorcodes.py eslint pylint mypy pydocstyle yapf	buildscripts/scons.py lint-fast
lint-clang-format	clang-format	buildscripts/scons.py lint-clang-format
lint-errorcodes	errorcodes.py	buildscripts/scons.py lint-errorcodes
lint-lint.py	quickcpplint.py	buildscripts/scons.py lint-lint.py
lint-eslint	eslint	buildscripts/scons.py lint-eslint
lint-pylinters	pylint mypy pydocstyle yapf	buildscripts/scons.py lint-pylinters
lint-sconslinters	yapf	buildscripts/scons.py lint-sconslinters