UPD: Migrate flake8 to ruff

.github/workflows/ci.yml

@@ -16,6 +16,6 @@ jobs:
       - name: Install linting package
         run: |
           python -m pip install --upgrade pip
-          pip install flake8
+          pip install ruff
       - name: Run linting
-        run: flake8 --count --show-source --statistics --max-line-length=120
+        run: ruff check

.gitlab-ci.yml

@@ -0,0 +1,22 @@
+default:
+  image: debian:latest
+
+before_script:
+  - apt-get -y update
+  - command -v git || apt-get -y install git
+  - command -v python3 || apt-get -y install python3
+  - command -v pip3 || apt-get -y install python3-pip
+  - python3 -V  # Print out python version for debugging
+  - python3 -m venv || apt-get -y install python3-venv
+  - python3 -m venv venv && source venv/bin/activate
+  - command -v venv/bin/ruff || venv/bin/pip3 install ruff
+
+stages:
+  - lint
+
+ruff:
+  stage: lint
+  script:
+    - ruff check
+  needs: []
+  allow_failure: false

pyproject.toml

@@ -22,4 +22,12 @@ dependencies = [
 ]
 
 [project.optional-dependencies]
-dev = ['flake8']
+dev = ['ruff']
+
+[tool.ruff]
+# Same as Black.
+line-length = 120
+indent-width = 4
+
+# Assume Python 3.9
+target-version = "py311"