Enable Flake8 in the CI builds

.flake8

@@ -0,0 +1,3 @@
+[flake8]
+max-line-length = 125
+ignore = F841,F821,W503,E402

.github/workflows/flake8.yml

@@ -0,0 +1,23 @@
+name: Run flake8 validation
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    strategy:
+      matrix:
+        python-version: ['3.9']
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Run flake8 verification
+      run: |
+        ./scripts/run_flake8.sh

examples/django/myslackapp/urls.py

@@ -13,7 +13,7 @@
     1. Import the include() function: from django.urls import include, path
     2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
 """
-from django.contrib import admin
+from django.contrib import admin  # noqa: F401
 from django.urls import path
 
 # Set this flag to False if you want to enable oauth_app instead

examples/django/simple_app/models.py

@@ -1,3 +1,3 @@
-from django.db import models
+from django.db import models  # noqa: F401
 
 # Create your models here.

examples/getting_started/app.py

@@ -7,6 +7,7 @@
     signing_secret=os.environ.get("SLACK_SIGNING_SECRET"),
 )
 
+
 # Listens to incoming messages that contain "hello"
 # To learn available listener method arguments,
 # visit https://slack.dev/bolt-python/api-docs/slack_bolt/kwargs_injection/args.html

examples/google_cloud_functions/main.py

@@ -26,6 +26,7 @@ def event_test(body, say, logger):
 
 handler = SlackRequestHandler(app)
 
+
 # Cloud Function
 def hello_bolt_app(request):
     """HTTP Cloud Function.

examples/workflow_steps/async_steps_from_apps.py

@@ -28,7 +28,7 @@ async def edit(ack: AsyncAck, step: dict, configure: AsyncConfigure):
                 "block_id": "intro-section",
                 "text": {
                     "type": "plain_text",
-                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",
+                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",  # noqa: E501
                 },
             },
             {
@@ -155,8 +155,8 @@ async def execute(
                 "blocks": blocks,
             },
         )
-    except:
-        await fail(error={"message": "Something wrong!"})
+    except Exception as e:
+        await fail(error={"message": f"Something wrong! (error: {e})"})
 
 
 app.step(

examples/workflow_steps/async_steps_from_apps_decorator.py

@@ -33,7 +33,7 @@ async def edit(ack: AsyncAck, step: dict, configure: AsyncConfigure):
                 "block_id": "intro-section",
                 "text": {
                     "type": "plain_text",
-                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",
+                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",  # noqa: E501
                 },
             },
             {

examples/workflow_steps/async_steps_from_apps_primitive.py

@@ -27,7 +27,7 @@ async def edit(body: dict, ack: AsyncAck, client: AsyncWebClient):
                     "block_id": "intro-section",
                     "text": {
                         "type": "plain_text",
-                        "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",
+                        "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",  # noqa: E501
                     },
                 },
                 {

examples/workflow_steps/steps_from_apps.py

@@ -31,7 +31,7 @@ def edit(ack: Ack, step, configure: Configure):
                 "block_id": "intro-section",
                 "text": {
                     "type": "plain_text",
-                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",
+                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",  # noqa: E501
                 },
             },
             {

examples/workflow_steps/steps_from_apps_decorator.py

@@ -35,7 +35,7 @@ def edit(ack: Ack, step, configure: Configure):
                 "block_id": "intro-section",
                 "text": {
                     "type": "plain_text",
-                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",
+                    "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",  # noqa: E501
                 },
             },
             {

examples/workflow_steps/steps_from_apps_primitive.py

@@ -29,7 +29,7 @@ def edit(body: dict, ack: Ack, client: WebClient):
                     "block_id": "intro-section",
                     "text": {
                         "type": "plain_text",
-                        "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",
+                        "text": "Create a task in one of the listed projects. The link to the task and other details will be available as variable data in later steps.",  # noqa: E501
                     },
                 },
                 {

scripts/run_flake8.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+# ./scripts/run_flake8.sh
+
+script_dir=$(dirname $0)
+cd ${script_dir}/.. && \
+  pip install "flake8==4.0.1" && \
+  flake8 slack_bolt/ && flake8 examples/

slack_bolt/__init__.py

@@ -1,10 +1,10 @@
 """
-A Python framework to build Slack apps in a flash with the latest platform features. Read the [getting started guide](https://slack.dev/bolt-python/tutorial/getting-started) and look at our [code examples](https://github.com/slackapi/bolt-python/tree/main/examples) to learn how to build apps using Bolt.
+A Python framework to build Slack apps in a flash with the latest platform features.Read the [getting started guide](https://slack.dev/bolt-python/tutorial/getting-started) and look at our [code examples](https://github.com/slackapi/bolt-python/tree/main/examples) to learn how to build apps using Bolt.
 
 * Website: https://slack.dev/bolt-python/
 * GitHub repository: https://github.com/slackapi/bolt-python
 * The class representing a Bolt app: `slack_bolt.app.app`
-"""
+"""  # noqa: E501
 # Don't add async module imports here
 from .app import App  # noqa
 from .context import BoltContext  # noqa

slack_bolt/adapter/aws_lambda/__init__.py

@@ -1 +1 @@
-from .handler import SlackRequestHandler
+from .handler import SlackRequestHandler  # noqa: F401

slack_bolt/adapter/bottle/__init__.py

@@ -1 +1 @@
-from .handler import SlackRequestHandler
+from .handler import SlackRequestHandler  # noqa: F401

slack_bolt/adapter/cherrypy/__init__.py

@@ -1 +1 @@
-from .handler import SlackRequestHandler
+from .handler import SlackRequestHandler  # noqa: F401

slack_bolt/adapter/django/__init__.py

@@ -1 +1 @@
-from .handler import SlackRequestHandler
+from .handler import SlackRequestHandler  # noqa: F401

slack_bolt/adapter/django/handler.py

@@ -142,8 +142,8 @@ def __init__(self, app: App):  # type: ignore
             # it's okay to skip calling the same connection clean-up method at the listener completion.
             message = """As you've already set app.listener_runner.listener_start_handler to your own one,
             Bolt skipped to set it to slack_sdk.adapter.django.DjangoListenerStartHandler.
-            
-            If you go with your own handler here, we highly recommend having the following lines of code 
+
+            If you go with your own handler here, we highly recommend having the following lines of code
             in your handle() method to clean up unmanaged stale/old database connections:
 
             from django.db import close_old_connections

slack_bolt/adapter/falcon/__init__.py

@@ -1,2 +1,2 @@
 # Don't add async module imports here
-from .resource import SlackAppResource
+from .resource import SlackAppResource  # noqa: F401

slack_bolt/adapter/flask/__init__.py

@@ -1 +1 @@
-from .handler import SlackRequestHandler
+from .handler import SlackRequestHandler  # noqa: F401

slack_bolt/adapter/pyramid/__init__.py

@@ -1 +1 @@
-from .handler import SlackRequestHandler
+from .handler import SlackRequestHandler  # noqa: F401

slack_bolt/adapter/sanic/__init__.py

@@ -1 +1 @@
-from .async_handler import AsyncSlackRequestHandler
+from .async_handler import AsyncSlackRequestHandler  # noqa: F401

slack_bolt/adapter/socket_mode/__init__.py

@@ -4,7 +4,7 @@
 * `slack_bolt.adapter.socket_mode.websocket_client`
 * `slack_bolt.adapter.socket_mode.aiohttp`
 * `slack_bolt.adapter.socket_mode.websockets`
-"""
+"""  # noqa: E501
 
 # Don't add async module imports here
-from .builtin import SocketModeHandler  # noqa
+from .builtin import SocketModeHandler  # noqa: F401

slack_bolt/adapter/starlette/__init__.py

@@ -1,2 +1,2 @@
 # Don't add async module imports here
-from .handler import SlackRequestHandler
+from .handler import SlackRequestHandler  # noqa: F401

slack_bolt/adapter/tornado/__init__.py

@@ -1 +1 @@
-from .handler import SlackEventsHandler, SlackOAuthHandler
+from .handler import SlackEventsHandler, SlackOAuthHandler  # noqa: F401

slack_bolt/app/__init__.py

@@ -6,4 +6,4 @@
 """
 
 # Don't add async module imports here
-from .app import App  # type: ignore
+from .app import App  # noqa: F401 type: ignore

slack_bolt/async_app.py

@@ -43,7 +43,7 @@ async def command(ack, body, respond):
 Apps can be run the same way as the synchronous example above. If you'd prefer another async Web framework (e.g., Sanic, FastAPI, Starlette), take a look at [the built-in adapters](https://github.com/slackapi/bolt-python/tree/main/slack_bolt/adapter) and their corresponding [examples](https://github.com/slackapi/bolt-python/tree/main/examples).
 
 Refer to `slack_bolt.app.async_app` for more details.
-"""
+"""  # noqa: E501
 from .app.async_app import AsyncApp  # noqa
 from .context.ack.async_ack import AsyncAck  # noqa
 from .context.async_context import AsyncBoltContext  # noqa

slack_bolt/authorization/__init__.py

@@ -3,4 +3,4 @@
 
 Refer to https://slack.dev/bolt-python/concepts#authorization for details.
 """
-from .authorize_result import AuthorizeResult
+from .authorize_result import AuthorizeResult  # noqa

slack_bolt/context/__init__.py

@@ -6,4 +6,4 @@
 """
 
 # Don't add async module imports here
-from .context import BoltContext
+from .context import BoltContext  # noqa: F401

slack_bolt/context/ack/__init__.py

@@ -1,2 +1,2 @@
 # Don't add async module imports here
-from .ack import Ack
+from .ack import Ack  # noqa: F401

slack_bolt/context/ack/internals.py

@@ -61,7 +61,7 @@ def _set_response(
                     )
                 else:
                     raise ValueError(
-                        f"errors field is required for response_action: errors"
+                        "errors field is required for response_action: errors"
                     )
             else:
                 body = {"response_action": response_action}

slack_bolt/context/respond/__init__.py

@@ -1,2 +1,2 @@
 # Don't add async module imports here
-from .respond import Respond
+from .respond import Respond  # noqa: F401

slack_bolt/context/say/__init__.py

@@ -1,2 +1,2 @@
 # Don't add async module imports here
-from .say import Say
+from .say import Say  # noqa: F401

slack_bolt/kwargs_injection/__init__.py

@@ -5,5 +5,5 @@
 """
 
 # Don't add async module imports here
-from .args import Args
-from .utils import build_required_kwargs
+from .args import Args  # noqa: F401
+from .utils import build_required_kwargs  # noqa: F401

slack_bolt/kwargs_injection/utils.py

@@ -1,7 +1,7 @@
 # pytype: skip-file
 import inspect
 import logging
-from typing import Callable, Dict, Optional, Any, Sequence, List
+from typing import Callable, Dict, Optional, Any, Sequence
 
 from slack_bolt.request import BoltRequest
 from slack_bolt.response import BoltResponse

slack_bolt/lazy_listener/async_runner.py

@@ -1,6 +1,6 @@
 from abc import abstractmethod, ABCMeta
 from logging import Logger
-from typing import Callable, Awaitable, Any, Coroutine
+from typing import Callable, Awaitable
 
 from slack_bolt.lazy_listener.async_internals import to_runnable_function
 from slack_bolt.request.async_request import AsyncBoltRequest

slack_bolt/listener/builtins.py

@@ -1,5 +1,3 @@
-from slack_sdk.oauth import InstallationStore
-
 from slack_bolt.context.context import BoltContext
 from slack_sdk.oauth.installation_store.installation_store import InstallationStore
 

slack_bolt/listener_matcher/builtins.py

@@ -29,8 +29,7 @@
     from re import _pattern_type as Pattern
 else:
     from re import Pattern
-from typing import Callable, Awaitable, Any, Sequence, Optional, Union
-from typing import Union, Optional, Dict
+from typing import Callable, Awaitable, Any, Sequence, Optional, Union, Dict
 
 from slack_bolt.kwargs_injection import build_required_kwargs
 from slack_bolt.request import BoltRequest

slack_bolt/logger/messages.py

@@ -348,4 +348,7 @@ def debug_return_listener_middleware_response(
     listener_name: str, status: int, body: str, starting_time: float
 ) -> str:
     millis = int((time.time() - starting_time) * 1000)
-    return f"Responding with listener middleware's response - listener: {listener_name}, status: {status}, body: {body} ({millis} millis)"
+    return (
+        "Responding with listener middleware's response - "
+        f"listener: {listener_name}, status: {status}, body: {body} ({millis} millis)"
+    )

slack_bolt/middleware/__init__.py

@@ -6,13 +6,16 @@
 """
 
 # Don't add async module imports here
-from .authorization import SingleTeamAuthorization, MultiTeamsAuthorization
-from .custom_middleware import CustomMiddleware
-from .ignoring_self_events import IgnoringSelfEvents
-from .middleware import Middleware
-from .request_verification import RequestVerification
-from .ssl_check import SslCheck
-from .url_verification import UrlVerification
+from .authorization import (
+    SingleTeamAuthorization,
+    MultiTeamsAuthorization,
+)  # noqa: F401
+from .custom_middleware import CustomMiddleware  # noqa: F401
+from .ignoring_self_events import IgnoringSelfEvents  # noqa: F401
+from .middleware import Middleware  # noqa: F401
+from .request_verification import RequestVerification  # noqa: F401
+from .ssl_check import SslCheck  # noqa: F401
+from .url_verification import UrlVerification  # noqa: F401
 
 builtin_middleware_classes = [
     SslCheck,

slack_bolt/middleware/async_builtins.py

@@ -1,11 +1,11 @@
-from .ignoring_self_events.async_ignoring_self_events import (
+from .ignoring_self_events.async_ignoring_self_events import (  # noqa: F401
     AsyncIgnoringSelfEvents,
-)  # noqa
-from .request_verification.async_request_verification import (
+)
+from .request_verification.async_request_verification import (  # noqa: F401
     AsyncRequestVerification,
-)  # noqa
-from .ssl_check.async_ssl_check import AsyncSslCheck  # noqa
-from .url_verification.async_url_verification import AsyncUrlVerification  # noqa
-from .message_listener_matches.async_message_listener_matches import (
+)
+from .ssl_check.async_ssl_check import AsyncSslCheck  # noqa: F401
+from .url_verification.async_url_verification import AsyncUrlVerification  # noqa: F401
+from .message_listener_matches.async_message_listener_matches import (  # noqa: F401
     AsyncMessageListenerMatches,
-)  # noqa
+)

slack_bolt/middleware/authorization/__init__.py

@@ -1,4 +1,4 @@
 # Don't add async module imports here
-from .authorization import Authorization
-from .multi_teams_authorization import MultiTeamsAuthorization
-from .single_team_authorization import SingleTeamAuthorization
+from .authorization import Authorization  # noqa: F401
+from .multi_teams_authorization import MultiTeamsAuthorization  # noqa: F401
+from .single_team_authorization import SingleTeamAuthorization  # noqa: F401

slack_bolt/middleware/ssl_check/ssl_check.py

@@ -23,7 +23,7 @@ def __init__(
             verification_token: The verification token to check
                 (optional as it's already deprecated - https://api.slack.com/authentication/verifying-requests-from-slack#verification_token_deprecation)
             base_logger: The base logger
-        """
+        """  # noqa: E501
         self.verification_token = verification_token
         self.logger = get_bolt_logger(SslCheck, base_logger=base_logger)
 

slack_bolt/oauth/internals.py

@@ -91,7 +91,7 @@ def _build_default_install_page_html(url: str) -> str:
 <p><a href="{url}"><img alt=""Add to Slack"" height="40" width="139" src="https://platform.slack-edge.com/img/add_to_slack.png" srcset="https://platform.slack-edge.com/img/add_to_slack.png 1x, https://platform.slack-edge.com/img/add_to_slack@2x.png 2x" /></a></p>
 </body>
 </html>
-"""
+"""  # noqa: E501
 
 
 # key: client_id, value: InstallationStore

slack_bolt/request/__init__.py

@@ -4,4 +4,4 @@
 This interface encapsulates the difference between the two.
 """
 # Don't add async module imports here
-from .request import BoltRequest
+from .request import BoltRequest  # noqa: F401

slack_bolt/response/__init__.py

@@ -6,4 +6,4 @@
 Refer to https://api.slack.com/apis/connections for the two types of connections.
 """
 
-from .response import BoltResponse
+from .response import BoltResponse  # noqa: F401

slack_bolt/workflows/step/__init__.py

@@ -1,6 +1,6 @@
-from .step import WorkflowStep
-from .step_middleware import WorkflowStepMiddleware
-from .utilities.complete import Complete
-from .utilities.configure import Configure
-from .utilities.update import Update
-from .utilities.fail import Fail
+from .step import WorkflowStep  # noqa: F401
+from .step_middleware import WorkflowStepMiddleware  # noqa: F401
+from .utilities.complete import Complete  # noqa: F401
+from .utilities.configure import Configure  # noqa: F401
+from .utilities.update import Update  # noqa: F401
+from .utilities.fail import Fail  # noqa: F401