Add black, isort, and flake8 linters

Author: LilSpazJoekp

.flake8

@@ -0,0 +1,2 @@
+[flake8]
+ignore = E203 E501 W503 W504

.github/PULL_REQUEST_TEMPLATE.md

@@ -8,6 +8,7 @@ What changes were made?
 
 ## Checklist
 
+- [ ] I've run the `pre_push.py` script to format and lint code.
 - [ ] I've checked this pull request runs on `Python 3.6.X`.
 - [ ] This fixes something in [Issues](https://github.com/eunwoo1104/discord-py-slash-command/issues).
     - Issue:

.github/workflows/ci.yml

@@ -0,0 +1,33 @@
+jobs:
+  lint-multi-os:
+    name: Lint ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v1
+      with:
+        python-version: 3.x
+    - uses: actions/cache@v1
+      with:
+        key: v0-${{ runner.os }}-pip-lint-${{ hashFiles('setup.py') }}
+        path: ~/.cache/pip
+        restore-keys: |
+          v0-${{ runner.os }}-pip-lint-
+          v0-${{ runner.os }}-pip-
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install .[lint]
+    - name: Run black
+      run: black --check --verbose .
+    - name: Run flake8
+      run: flake8 --exclude docs --statistics
+    - name: Run isort
+      run: isort -cv .
+    - name: Run sphinx
+      run: sphinx-build -W --keep-going docs/ /tmp/foo
+    strategy:
+      matrix:
+        os: [macOS-latest, ubuntu-latest, windows-latest]
+name: CI
+on: [pull_request, push]

pre_push.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+"""Run static analysis on the project."""
+
+import sys
+from os import path
+from shutil import rmtree
+from subprocess import CalledProcessError, check_call
+from tempfile import mkdtemp
+
+current_directory = path.abspath(path.join(__file__, ".."))
+
+
+def do_process(args, shell=False):
+    """Run program provided by args.
+
+    Return True on success.
+
+    Output failed message on non-zero exit and return False.
+
+    Exit if command is not found.
+
+    """
+    print(f"Running: {' '.join(args)}")
+    try:
+        check_call(args, shell=shell)
+    except CalledProcessError:
+        print(f"\nFailed: {' '.join(args)}")
+        return False
+    except Exception as exc:
+        sys.stderr.write(f"{str(exc)}\n")
+        sys.exit(1)
+    return True
+
+
+def run_static():
+    """Runs static tests.
+
+    Returns a statuscode of 0 if everything ran correctly. Otherwise, it will return
+    statuscode 1
+
+    """
+    success = True
+    # Formatters
+    success &= do_process(["black", "."])
+    success &= do_process(["isort", "."])
+    # Linters
+    success &= do_process(["flake8", "--exclude=.eggs,build,docs,.venv*"])
+
+    tmp_dir = mkdtemp()
+    try:
+        success &= do_process(["sphinx-build", "-W", "--keep-going", "docs", tmp_dir])
+    finally:
+        rmtree(tmp_dir)
+
+    return success
+
+
+def main():
+    success = True
+    try:
+        success &= run_static()
+    except KeyboardInterrupt:
+        return 1
+    return int(not success)
+
+
+if __name__ == "__main__":
+    exit_code = main()
+    print("\npre_push.py: Success!" if not exit_code else "\npre_push.py: Fail")
+    sys.exit(exit_code)

pyproject.toml

@@ -0,0 +1,7 @@
+[tool.black]
+exclude = '/(\.eggs|\.git|\.mypy_cache|\.venv.*|_build|build|dist)/'
+line-length = 100
+
+[tool.isort]
+profile = "black"
+line_length = 100

setup.py

@@ -13,8 +13,11 @@
     VERSION = re.search('__version__ = "([^"]+)"', fp.read()).group(1)
 
 extras = {
+    "lint": ["black", "flake8", "isort"],
     "readthedocs": ["sphinx", "sphinx-rtd-theme"],
 }
+extras["lint"] += extras["readthedocs"]
+extras["dev"] = extras["lint"] + extras["readthedocs"]
 
 setup(
     name="discord-py-slash-command",