Merge pull request #2128 from Textualize/fix-2063

Fix issues with watching CSS reloading
Textualize · Mar 28, 2023 · 0189918 · 0189918
2 parents eaca92b + a06b59f
commit 0189918
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Showing 8 changed files with 222 additions and 7 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Issue with parsing action strings whose arguments contained quoted closing parenthesis https://github.com/Textualize/textual/pull/2112
 - Issues with parsing action strings with tuple arguments https://github.com/Textualize/textual/pull/2112
+- Issue with watching for CSS file changes https://github.com/Textualize/textual/pull/2128
 - Fix for tabs not invalidating https://github.com/Textualize/textual/issues/2125
 - Fixed scrollbar layers issue https://github.com/Textualize/textual/issues/1358
 - Fix for interaction between pseudo-classes and widget-level render caches https://github.com/Textualize/textual/pull/2155

diff --git a/src/textual/_doc.py b/src/textual/_doc.py
@@ -1,10 +1,11 @@
 from __future__ import annotations
 
 import hashlib
+import inspect
 import os
 import shlex
 from pathlib import Path
-from typing import Iterable, cast
+from typing import Awaitable, Callable, Iterable, cast
 
 from textual._import_app import import_app
 from textual.app import App
@@ -54,6 +55,7 @@ def take_svg_screenshot(
     press: Iterable[str] = (),
     title: str | None = None,
     terminal_size: tuple[int, int] = (80, 24),
+    run_before: Callable[[Pilot], Awaitable[None] | None] | None = None,
 ) -> str:
     """
 
@@ -63,11 +65,13 @@ def take_svg_screenshot(
         press: Key presses to run before taking screenshot. "_" is a short pause.
         title: The terminal title in the output image.
         terminal_size: A pair of integers (rows, columns), representing terminal size.
+        run_before: An arbitrary callable that runs arbitrary code before taking the
+            screenshot. Use this to simulate complex user interactions with the app
+            that cannot be simulated by key presses.
 
     Returns:
         An SVG string, showing the content of the terminal window at the time
             the screenshot was taken.
-
     """
 
     if app is None:
@@ -90,7 +94,7 @@ def get_cache_key(app: App) -> str:
         cache_key = f"{hash.hexdigest()}.svg"
         return cache_key
 
-    if app_path is not None:
+    if app_path is not None and run_before is None:
         screenshot_cache = Path(SCREENSHOT_CACHE)
         screenshot_cache.mkdir(exist_ok=True)
 
@@ -100,6 +104,10 @@ def get_cache_key(app: App) -> str:
 
     async def auto_pilot(pilot: Pilot) -> None:
         app = pilot.app
+        if run_before is not None:
+            result = run_before(pilot)
+            if inspect.isawaitable(result):
+                await result
         await pilot.press(*press)
         await pilot.wait_for_scheduled_animations()
         await pilot.pause()
@@ -116,7 +124,7 @@ async def auto_pilot(pilot: Pilot) -> None:
         ),
     )
 
-    if app_path is not None:
+    if app_path is not None and run_before is None:
         screenshot_path.write_text(svg)
 
     assert svg is not None

diff --git a/src/textual/app.py b/src/textual/app.py
@@ -1081,7 +1081,6 @@ async def _on_css_change(self) -> None:
                 self.bell()
             else:
                 self.stylesheet = stylesheet
-                self.reset_styles()
                 self.stylesheet.update(self)
                 self.screen.refresh(layout=True)
 

diff --git a/tests/snapshot_tests/__snapshots__/test_snapshots.ambr b/tests/snapshot_tests/__snapshots__/test_snapshots.ambr
@@ -1985,6 +1985,161 @@
 
   '''
 # ---
+# name: test_css_hot_reloading
+  '''
+  <svg class="rich-terminal" viewBox="0 0 994 635.5999999999999" xmlns="http://www.w3.org/2000/svg">
+      <!-- Generated with Rich https://www.textualize.io -->
+      <style>
+
+      @font-face {
+          font-family: "Fira Code";
+          src: local("FiraCode-Regular"),
+                  url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Regular.woff2") format("woff2"),
+                  url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Regular.woff") format("woff");
+          font-style: normal;
+          font-weight: 400;
+      }
+      @font-face {
+          font-family: "Fira Code";
+          src: local("FiraCode-Bold"),
+                  url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Bold.woff2") format("woff2"),
+                  url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Bold.woff") format("woff");
+          font-style: bold;
+          font-weight: 700;
+      }
+
+      .terminal-3709538693-matrix {
+          font-family: Fira Code, monospace;
+          font-size: 20px;
+          line-height: 24.4px;
+          font-variant-east-asian: full-width;
+      }
+
+      .terminal-3709538693-title {
+          font-size: 18px;
+          font-weight: bold;
+          font-family: arial;
+      }
+
+      .terminal-3709538693-r1 { fill: #e1e1e1 }
+  .terminal-3709538693-r2 { fill: #c5c8c6 }
+      </style>
+
+      <defs>
+      <clipPath id="terminal-3709538693-clip-terminal">
+        <rect x="0" y="0" width="975.0" height="584.5999999999999" />
+      </clipPath>
+      <clipPath id="terminal-3709538693-line-0">
+      <rect x="0" y="1.5" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-1">
+      <rect x="0" y="25.9" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-2">
+      <rect x="0" y="50.3" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-3">
+      <rect x="0" y="74.7" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-4">
+      <rect x="0" y="99.1" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-5">
+      <rect x="0" y="123.5" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-6">
+      <rect x="0" y="147.9" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-7">
+      <rect x="0" y="172.3" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-8">
+      <rect x="0" y="196.7" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-9">
+      <rect x="0" y="221.1" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-10">
+      <rect x="0" y="245.5" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-11">
+      <rect x="0" y="269.9" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-12">
+      <rect x="0" y="294.3" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-13">
+      <rect x="0" y="318.7" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-14">
+      <rect x="0" y="343.1" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-15">
+      <rect x="0" y="367.5" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-16">
+      <rect x="0" y="391.9" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-17">
+      <rect x="0" y="416.3" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-18">
+      <rect x="0" y="440.7" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-19">
+      <rect x="0" y="465.1" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-20">
+      <rect x="0" y="489.5" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-21">
+      <rect x="0" y="513.9" width="976" height="24.65"/>
+              </clipPath>
+  <clipPath id="terminal-3709538693-line-22">
+      <rect x="0" y="538.3" width="976" height="24.65"/>
+              </clipPath>
+      </defs>
+
+      <rect fill="#292929" stroke="rgba(255,255,255,0.35)" stroke-width="1" x="1" y="1" width="992" height="633.6" rx="8"/><text class="terminal-3709538693-title" fill="#c5c8c6" text-anchor="middle" x="496" y="27">HotReloadingApp</text>
+              <g transform="translate(26,22)">
+              <circle cx="0" cy="0" r="7" fill="#ff5f57"/>
+              <circle cx="22" cy="0" r="7" fill="#febc2e"/>
+              <circle cx="44" cy="0" r="7" fill="#28c840"/>
+              </g>
+
+      <g transform="translate(9, 41)" clip-path="url(#terminal-3709538693-clip-terminal)">
+      <rect fill="#1e1e1e" x="0" y="1.5" width="158.6" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="158.6" y="1.5" width="817.4" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="25.9" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="50.3" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="74.7" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="99.1" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="123.5" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="147.9" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="172.3" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="196.7" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="221.1" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="245.5" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="269.9" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="294.3" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="318.7" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="343.1" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="367.5" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="391.9" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="416.3" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="440.7" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="465.1" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="489.5" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="513.9" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="538.3" width="976" height="24.65" shape-rendering="crispEdges"/><rect fill="#1e1e1e" x="0" y="562.7" width="976" height="24.65" shape-rendering="crispEdges"/>
+      <g class="terminal-3709538693-matrix">
+      <text class="terminal-3709538693-r1" x="0" y="20" textLength="158.6" clip-path="url(#terminal-3709538693-line-0)">Hello,&#160;world!</text><text class="terminal-3709538693-r2" x="976" y="20" textLength="12.2" clip-path="url(#terminal-3709538693-line-0)">
+  </text><text class="terminal-3709538693-r2" x="976" y="44.4" textLength="12.2" clip-path="url(#terminal-3709538693-line-1)">
+  </text><text class="terminal-3709538693-r2" x="976" y="68.8" textLength="12.2" clip-path="url(#terminal-3709538693-line-2)">
+  </text><text class="terminal-3709538693-r2" x="976" y="93.2" textLength="12.2" clip-path="url(#terminal-3709538693-line-3)">
+  </text><text class="terminal-3709538693-r2" x="976" y="117.6" textLength="12.2" clip-path="url(#terminal-3709538693-line-4)">
+  </text><text class="terminal-3709538693-r2" x="976" y="142" textLength="12.2" clip-path="url(#terminal-3709538693-line-5)">
+  </text><text class="terminal-3709538693-r2" x="976" y="166.4" textLength="12.2" clip-path="url(#terminal-3709538693-line-6)">
+  </text><text class="terminal-3709538693-r2" x="976" y="190.8" textLength="12.2" clip-path="url(#terminal-3709538693-line-7)">
+  </text><text class="terminal-3709538693-r2" x="976" y="215.2" textLength="12.2" clip-path="url(#terminal-3709538693-line-8)">
+  </text><text class="terminal-3709538693-r2" x="976" y="239.6" textLength="12.2" clip-path="url(#terminal-3709538693-line-9)">
+  </text><text class="terminal-3709538693-r2" x="976" y="264" textLength="12.2" clip-path="url(#terminal-3709538693-line-10)">
+  </text><text class="terminal-3709538693-r2" x="976" y="288.4" textLength="12.2" clip-path="url(#terminal-3709538693-line-11)">
+  </text><text class="terminal-3709538693-r2" x="976" y="312.8" textLength="12.2" clip-path="url(#terminal-3709538693-line-12)">
+  </text><text class="terminal-3709538693-r2" x="976" y="337.2" textLength="12.2" clip-path="url(#terminal-3709538693-line-13)">
+  </text><text class="terminal-3709538693-r2" x="976" y="361.6" textLength="12.2" clip-path="url(#terminal-3709538693-line-14)">
+  </text><text class="terminal-3709538693-r2" x="976" y="386" textLength="12.2" clip-path="url(#terminal-3709538693-line-15)">
+  </text><text class="terminal-3709538693-r2" x="976" y="410.4" textLength="12.2" clip-path="url(#terminal-3709538693-line-16)">
+  </text><text class="terminal-3709538693-r2" x="976" y="434.8" textLength="12.2" clip-path="url(#terminal-3709538693-line-17)">
+  </text><text class="terminal-3709538693-r2" x="976" y="459.2" textLength="12.2" clip-path="url(#terminal-3709538693-line-18)">
+  </text><text class="terminal-3709538693-r2" x="976" y="483.6" textLength="12.2" clip-path="url(#terminal-3709538693-line-19)">
+  </text><text class="terminal-3709538693-r2" x="976" y="508" textLength="12.2" clip-path="url(#terminal-3709538693-line-20)">
+  </text><text class="terminal-3709538693-r2" x="976" y="532.4" textLength="12.2" clip-path="url(#terminal-3709538693-line-21)">
+  </text><text class="terminal-3709538693-r2" x="976" y="556.8" textLength="12.2" clip-path="url(#terminal-3709538693-line-22)">
+  </text>
+      </g>
+      </g>
+  </svg>
+
+  '''
+# ---
 # name: test_css_property[align.py]
   '''
   <svg class="rich-terminal" viewBox="0 0 994 635.5999999999999" xmlns="http://www.w3.org/2000/svg">

diff --git a/tests/snapshot_tests/conftest.py b/tests/snapshot_tests/conftest.py
@@ -7,7 +7,7 @@
 from operator import attrgetter
 from os import PathLike
 from pathlib import Path, PurePath
-from typing import Union, List, Optional, Callable, Iterable
+from typing import Awaitable, Union, List, Optional, Callable, Iterable
 
 import pytest
 from _pytest.config import ExitCode
@@ -21,6 +21,7 @@
 from textual._doc import take_svg_screenshot
 from textual._import_app import import_app
 from textual.app import App
+from textual.pilot import Pilot
 
 TEXTUAL_SNAPSHOT_SVG_KEY = pytest.StashKey[str]()
 TEXTUAL_ACTUAL_SVG_KEY = pytest.StashKey[str]()
@@ -42,6 +43,7 @@ def compare(
         app_path: str | PurePath,
         press: Iterable[str] = ("_",),
         terminal_size: tuple[int, int] = (80, 24),
+        run_before: Callable[[Pilot], Awaitable[None] | None] | None = None,
     ) -> bool:
         """
         Compare a current screenshot of the app running at app_path, with
@@ -54,9 +56,12 @@ def compare(
                 test this function is called from.
             press (Iterable[str]): Key presses to run before taking screenshot. "_" is a short pause.
             terminal_size (tuple[int, int]): A pair of integers (WIDTH, HEIGHT), representing terminal size.
+            run_before: An arbitrary callable that runs arbitrary code before taking the
+                screenshot. Use this to simulate complex user interactions with the app
+                that cannot be simulated by key presses.
 
         Returns:
-            bool: True if the screenshot matches the snapshot.
+            Whether the screenshot matches the snapshot.
         """
         node = request.node
         path = Path(app_path)
@@ -74,6 +79,7 @@ def compare(
             app=app,
             press=press,
             terminal_size=terminal_size,
+            run_before=run_before,
         )
         result = snapshot == actual_screenshot
 

diff --git a/tests/snapshot_tests/snapshot_apps/hot_reloading_app.css b/tests/snapshot_tests/snapshot_apps/hot_reloading_app.css
@@ -0,0 +1 @@
+/* This file is purposefully empty. */
diff --git a/tests/snapshot_tests/snapshot_apps/hot_reloading_app.py b/tests/snapshot_tests/snapshot_apps/hot_reloading_app.py
@@ -0,0 +1,31 @@
+from pathlib import Path
+
+from textual.app import App, ComposeResult
+from textual.containers import Container
+from textual.widgets import Label
+
+
+CSS_PATH = (Path(__file__) / "../hot_reloading_app.css").resolve()
+
+# Write some CSS to the file before the app loads.
+# Then, the test will clear all the CSS to see if the
+# hot reloading applies the changes correctly.
+CSS_PATH.write_text(
+    """
+Container {
+    align: center middle;
+}
+
+Label {
+    border: round $primary;
+    padding: 3;
+}
+"""
+)
+
+
+class HotReloadingApp(App[None]):
+    CSS_PATH = CSS_PATH
+
+    def compose(self) -> ComposeResult:
+        yield Container(Label("Hello, world!"))
diff --git a/tests/snapshot_tests/test_snapshots.py b/tests/snapshot_tests/test_snapshots.py
@@ -342,6 +342,20 @@ def test_scrollbar_thumb_height(snap_compare):
     )
 
 
+def test_css_hot_reloading(snap_compare):
+    """Regression test for https://github.com/Textualize/textual/issues/2063."""
+
+    async def run_before(pilot):
+        css_file = pilot.app.CSS_PATH
+        with open(css_file, "w") as f:
+            f.write("/* This file is purposefully empty. */\n")  # Clear all the CSS.
+        await pilot.app._on_css_change()
+
+    assert snap_compare(
+        SNAPSHOT_APPS_DIR / "hot_reloading_app.py", run_before=run_before
+    )
+
+
 def test_layer_fix(snap_compare):
     # Check https://github.com/Textualize/textual/issues/1358
     assert snap_compare(SNAPSHOT_APPS_DIR / "layer_fix.py", press=["d"])