chore: add pre-commit config mirroring the CI lint job

.github/workflows/ci.yml

@@ -57,6 +57,7 @@ jobs:
           uv run coverage erase
           uv run coverage run -m pytest
           uv run coverage report
+          uv run coverage xml
       - name: Upload coverage data
         if: always()
         uses: actions/upload-artifact@v7
@@ -66,6 +67,11 @@ jobs:
           include-hidden-files: true
           if-no-files-found: error
           retention-days: 7
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v6
+        with:
+          files: coverage.xml
+          fail_ci_if_error: false
 
   build:
     name: Build & audit package

.gitignore

@@ -21,6 +21,7 @@ build/
 .pytest_cache/
 .tox/
 .coverage
+coverage.xml
 htmlcov/
 .mypy_cache/
 .ruff_cache/

.pre-commit-config.yaml

@@ -0,0 +1,23 @@
+# Mirrors the lint job in .github/workflows/ci.yml (ruff check, ruff format,
+# mypy) so contributors get the same checks locally before pushing.
+repos:
+  - repo: local
+    hooks:
+      - id: ruff-check
+        name: ruff check
+        entry: uv run ruff check .
+        language: system
+        types: [python]
+        pass_filenames: false
+      - id: ruff-format
+        name: ruff format
+        entry: uv run ruff format --check .
+        language: system
+        types: [python]
+        pass_filenames: false
+      - id: mypy
+        name: mypy type check
+        entry: uv run mypy gcode
+        language: system
+        types: [python]
+        pass_filenames: false

CONTRIBUTING.md

@@ -46,6 +46,21 @@ Look for issues labeled [`good first issue`](https://github.com/shauryagangrade/
 - Write clean, readable code with descriptive variable names.
 - Ensure all tests pass before opening a PR.
 
+## Pre-commit Hooks
+
+Install the hooks once so lint, formatting, and type checks run before every
+commit (they mirror the CI lint job):
+
+```bash
+uv run pre-commit install
+```
+
+Run them on the whole tree any time with:
+
+```bash
+uv run pre-commit run --all-files
+```
+
 ---
 
 ## PR Guidelines

README.md

@@ -1,6 +1,7 @@
 # GCode
 
 ![Build](https://github.com/shauryagangrade/GCode/actions/workflows/ci.yml/badge.svg)
+[![codecov](https://codecov.io/gh/shauryagangrade/GCode/branch/main/graph/badge.svg)](https://codecov.io/gh/shauryagangrade/GCode)
 [![License: Apache 2.0](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](LICENSE)
 [![PyPI version](https://img.shields.io/pypi/v/gcode.svg)](https://pypi.org/project/gcode/)
 [![Stars](https://img.shields.io/github/stars/shauryagangrade/GCode?style=social)](https://github.com/shauryagangrade/GCode)

pyproject.toml

@@ -20,6 +20,7 @@ dev = [
     "coverage>=7",
     "mypy>=1.13",
     "pip-audit>=2.7",
+    "pre-commit>=4.0",
     "pytest>=8",
     "ruff>=0.9",
 ]