Add pre-commit as a Flake8 and MyPy delegate

Author: arturdryomov

.github/workflows/ci.yml

@@ -3,6 +3,21 @@ name: ci
 on: [push, pull_request]
 
 jobs:
+  checks:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "Checkout the source code"
+        uses: actions/checkout@v2
+
+      - name: "Install Python"
+        uses: actions/setup-python@v2
+
+      - name: "Install pre-commit"
+        run: pip install pre-commit
+
+      - name: "Run pre-commit checks"
+        run: pre-commit run --all-files
+
   build:
     runs-on: ubuntu-latest
     strategy:
@@ -27,6 +42,3 @@ jobs:
       - name: Run tests
         run: |
           pytest -s tests/ integration_tests/
-      - name: Run linter
-        run: |
-          flake8

.pre-commit-config.yaml

@@ -0,0 +1,15 @@
+repos:
+  - repo: "https://github.com/PyCQA/flake8"
+    rev: "3.9.2"
+    hooks:
+      - id: "flake8"
+        name: "Python: analysis"
+
+  - repo: "https://github.com/pre-commit/mirrors-mypy"
+    rev: "v0.910"
+    hooks:
+      - id: "mypy"
+        name: "Python: types"
+        additional_dependencies:
+          - "types-pytz"
+          - "types-requests"

setup.py

@@ -22,16 +22,16 @@
 
 
 with open("trino/__init__.py", "rb") as f:
-    version = str(
-        ast.literal_eval(_version_re.search(f.read().decode("utf-8")).group(1))
-    )
+    trino_version = _version_re.search(f.read().decode("utf-8"))
+    assert trino_version is not None
+    version = str(ast.literal_eval(trino_version.group(1)))
 
 
 kerberos_require = ["requests_kerberos"]
 
-all_require = [kerberos_require]
+all_require = kerberos_require + []
 
-tests_require = all_require + ["httpretty", "pytest", "pytest-runner", "pytz", "flake8", "click"]
+tests_require = all_require + ["httpretty", "pytest", "pytest-runner", "pytz", "click"]
 
 setup(
     name="trino",

trino/client.py

@@ -52,7 +52,7 @@
 if SOCKS_PROXY:
     PROXIES = {"http": "socks5://" + SOCKS_PROXY, "https": "socks5://" + SOCKS_PROXY}
 else:
-    PROXIES = None
+    PROXIES = {}
 
 
 class ClientSession(object):
@@ -313,7 +313,7 @@ def statement_url(self) -> str:
         return self.get_url(constants.URL_STATEMENT_PATH)
 
     @property
-    def next_uri(self) -> str:
+    def next_uri(self) -> Optional[str]:
         return self._next_uri
 
     def post(self, sql, additional_http_headers=None):