Make devtools deps extras, add note to internal ref docs, raise excep…

.github/workflows/pythonpackage.yml

@@ -25,7 +25,7 @@ jobs:
           version: 1.1.6
           virtualenvs-in-project: true
       - name: Install dependencies
-        run: poetry install
+        run: poetry install --extras "dev"
         if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
       - name: Format check with black
         run: |

pyproject.toml

@@ -24,10 +24,16 @@ textual = "textual.cli.cli:run"
 python = "^3.7"
 rich = "^12.4.3"
 #rich = {path="../rich", develop=true}
-click = "8.1.2"
 importlib-metadata = "^4.11.3"
 typing-extensions = { version = "^4.0.0", python = "<3.8" }
-msgpack = "^1.0.3"
+
+# Dependencies below are required for devtools only
+aiohttp = { version = "^3.8.1", optional = true }
+click = {version = "8.1.2", optional = true}
+msgpack = { version = "^1.0.3", optional = true }
+
+[tool.poetry.extras]
+dev = ["aiohttp", "click", "msgpack"]
 
 [tool.poetry.dev-dependencies]
 pytest = "^6.2.3"

reference/_devtools.md

@@ -0,0 +1,14 @@
+# Devtools
+
+## Installation
+
+Using the Textual Devtools requires installation of the `dev` extra dependency.
+
+https://python-poetry.org/docs/pyproject/#extras
+
+## Running
+
+TODO: Note how we run the devtools themselves and how we run our Textual apps
+such that they can connect. Don't forget Windows instructions :)
+We might also add a link to the documentation from the exception that gets
+raised when the "dev" extra dependencies aren't installed.

src/textual/app.py

@@ -34,7 +34,7 @@
 from rich.console import Console, RenderableType
 from rich.measure import Measurement
 from rich.protocol import is_renderable
-from rich.segment import Segments, SegmentLines
+from rich.segment import Segments
 from rich.traceback import Traceback
 
 from . import actions
@@ -47,7 +47,6 @@
 from ._event_broker import extract_handler_actions, NoHandler
 from .binding import Bindings, NoBinding
 from .css.stylesheet import Stylesheet
-from .css.styles import RenderStyles
 from .css.query import NoMatchingNodesError
 from .design import ColorSystem
 from .devtools.client import DevtoolsClient, DevtoolsConnectionError, DevtoolsLog
@@ -61,7 +60,6 @@
 from .message_pump import MessagePump
 from .reactive import Reactive
 from .renderables.blank import Blank
-from ._profile import timer
 
 from .screen import Screen
 from .widget import Widget

src/textual/devtools/client.py

@@ -3,19 +3,35 @@
 import asyncio
 import inspect
 import json
-import msgpack
+
 import pickle
 from time import time
 from asyncio import Queue, Task, QueueFull
 from io import StringIO
 from typing import Type, Any, NamedTuple
 
-import aiohttp
-from aiohttp import ClientResponseError, ClientConnectorError, ClientWebSocketResponse
 from rich.console import Console
 from rich.segment import Segment
 
 
+class DevtoolsDependenciesMissingError(Exception):
+    """Raise when the required devtools dependencies are not installed in the environment"""
+
+
+try:
+    import aiohttp
+    from aiohttp import (
+        ClientResponseError,
+        ClientConnectorError,
+        ClientWebSocketResponse,
+    )
+    import msgpack
+except ImportError:
+    # TODO: Add link to documentation on how to install devtools
+    raise DevtoolsDependenciesMissingError(
+        "Textual Devtools requires installation of the 'dev' extra dependencies. "
+    )
+
 DEVTOOLS_PORT = 8081
 WEBSOCKET_CONNECT_TIMEOUT = 3
 LOG_QUEUE_MAXSIZE = 512