purkhusid / bazel-linting-system

🌿💚 Experimental system for registering, configuring, and invoking source-code linters in Bazel.

bazel-linting-system

This is an experimental project with the goals of providing a simple tool for linting source code within a polyglot Bazel repo and learning more about aspects. ⚠️ Currently it relies on being able to configure your linters to modify source 'in-place'. Thankfully most linters can do this.

See DESIGN.md for some discussion of the pros/cons of this project.

Usage

An example Bazel workspace exists in examples, with a lint.sh that runs the registered linters against all source code within the workspace.

Below is further explanation of the constituents of this system.

Setup

Add the following to your WORKSPACE file:

http_archive(
    name = "linting_system",
    sha256 = "",
    strip_prefix = "bazel-linting-system-0.3.0",
    url = "https://github.com/thundergolfer/bazel-linting-system/archive/v0.3.0.zip",
)

load("@linting_system//repositories:repositories.bzl", linting_sys_repositories = "repositories")
linting_sys_repositories()

load("@linting_system//repositories:go_repositories.bzl", linting_sys_deps = "go_deps")
linting_sys_deps()

Create an aspect.bzl extension file in a folder called tools/linting with the following:

load("@linting_system//:generator.bzl", "linting_aspect_generator")

lint = linting_aspect_generator(
    name = "lint",
    linters = [
        "@//tools/linting:python",
    ]
)

"@//tools/linting:python" is a label reference to target in a sibling BUILD file, for example:

load("@linting_system//:rules.bzl", "linter")

package(default_visibility = ['//visibility:public'])

linter(
    name = "python",
    executable_path = "/usr/local/bin/black",
    config = ":configuration/pyproject.toml",
    config_option = "--config",
)

linter targets define a path to the linter executable and optionally a config file for that linter.

⚠️ The name field in the linter rule must exactly match one of the supported languages. The list of supported languages is shown at the top of generator.bzl.

Run with:

bazel build //... \
    --aspects //tools/linting:aspect.bzl%lint \
    --output_groups=report

bazel run @linting_system//apply_changes -- \
  "$(git rev-parse --show-toplevel)" \
  "$(bazel info bazel-genfiles)" \
  "$(bazel query //... | tr '\n' ' ')"

Usually you'll want to wrap up the above in a simple script named something like lint.sh.

You can also add the aspect to your .bazelrc 🎉:

build --aspects //tools/linting:aspect.bzl%lint
build --output_groups=+report