linters: Add black

Add black python linter both as an action and as a Makefile rule.

Signed-off-by: Alex Apostolescu <[email protected]>

Author: Alex-deVis

.github/workflows/actions.yml

@@ -76,3 +76,30 @@ jobs:
           if [[ -n "${{ env.FILES }}" ]]; then
             cpplint --recursive --quiet ${{ env.FILES }}
           fi
+
+  black:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Get changed Python files
+        uses: tj-actions/changed-files@v45
+        id: changed-files
+        with:
+          files: "**/*.py"
+          separator: " "
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: 3.12
+
+      - uses: psf/black@stable
+        env:
+          # Black will fail if no arguments are provided.
+          # In that case check a directory without any python files.
+          FILES: ${{ steps.changed-files.outputs.all_changed_files || '.github' }}
+        with:
+          options: "--check --diff"
+          src: ${{ env.FILES }}

Makefile

@@ -40,8 +40,8 @@ clean: stop_bash
 cleanall: clean
 	-docker inspect --type=image $(IMAGE_NAME) > /dev/null 2>&1 && docker image rm $(IMAGE_NAME)
 
-.PHONY: lint markdownlint cpplint
-lint: markdownlint cpplint
+.PHONY: lint markdownlint cpplint black
+lint: markdownlint cpplint black
 
 CHANGED_MD_FILES = $(call get_changed_files,\.md$$)
 markdownlint:
@@ -60,6 +60,14 @@ cpplint: # Runs locally, requires cpplint installed
 		cpplint --recursive --quiet $(CHANGED_CPP_FILES); \
 	fi
 
+CHANGED_PY_FILES = $(call get_changed_files,\.py$$)
+black:
+	@echo "Checking Python files ..."
+	@if [ "$(CHANGED_PY_FILES)" ]; then \
+		docker run --rm -v $(PWD):/data --workdir=/data pyfound/black:latest \
+			black --check --diff $(CHANGED_PY_FILES); \
+	fi
+
 # Get a list of files that changed in the current branch and match the given pattern
 define get_changed_files # $(1): pattern
 $(shell git diff --name-only HEAD $(shell git merge-base HEAD main) | grep "$(1)" | tr '\n' ' ')