chore: release version 1.2.4 with optimized DevTools extension assets

- Reduced the size of published DevTools extension assets from ~43 MB to ~5.5 MB on disk and ~1 MB compressed by tree-shaking Material icons and omitting local CanvasKit.
- Updated README and hit_devtools_extension README to reflect changes in the build process and asset management.
- Enhanced build script to ensure efficient asset handling and pruning of unused files.

Author: definev

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 1.2.4
 
+- Shrink the published DevTools extension assets (~43 MB → ~5.5 MB on disk,
+  ~1 MB compressed archive): tree-shake Material icons and omit local
+  CanvasKit (loaded from the Flutter CDN at runtime). See `tool/build_devtools.sh`.
 - Add **Probe** mode to the hit DevTools extension: tap the connected app to
   list every hit area under that point (`Hit.probed`) with diagnostic notes
   for misses. Mutually exclusive with Select; reuses cancelled pointer

README.md

@@ -347,12 +347,15 @@ HitLayer(
 ```
 
 Rebuild the embedded web assets after changing the
-extension UI:
+extension UI (run before `pub publish`):
 
 ```bash
 ./tool/build_devtools.sh
 ```
 
+That script tree-shakes icons and drops unused local CanvasKit so the
+published archive stays small (~1 MB compressed).
+
 See [DevTools extensions](https://docs.flutter.dev/tools/devtools/extensions)
 and [`devtools_extensions`](https://pub.dev/packages/devtools_extensions).
 

hit_devtools_extension/README.md

@@ -6,6 +6,12 @@ Source lives here so it does not inflate `package:hit` for app users. Built
 assets are copied into `../extension/devtools/build` and shipped with the
 published package.
 
+`../tool/build_devtools.sh` builds with icon tree-shaking and strips the local
+`canvaskit/` directory (CanvasKit is loaded from the Flutter CDN via
+`engineRevision` in `flutter_bootstrap.js`). Prefer that script over
+`dart run devtools_extensions build_and_copy`, which ships ~40 MB of unused
+engine binaries (see [flutter/devtools#9897](https://github.com/flutter/devtools/issues/9897)).
+
 ## Develop
 
 ```bash

tool/build_devtools.sh

@@ -1,12 +1,48 @@
 #!/usr/bin/env bash
+# Build the hit DevTools extension web app into extension/devtools/build.
+#
+# Size notes (see flutter/devtools#9897):
+# - `devtools_extensions build_and_copy` hardcodes --no-tree-shake-icons and
+#   ships the full local canvaskit/ tree even though flutter_bootstrap.js loads
+#   CanvasKit from the gstatic CDN via engineRevision. We build ourselves with
+#   icon tree-shaking and prune canvaskit/ after copy.
 set -euo pipefail
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 EXT="$ROOT/hit_devtools_extension"
 DEST="$ROOT/extension/devtools"
+SRC_BUILD="$EXT/build/web"
+DEST_BUILD="$DEST/build"
 
 cd "$EXT"
 flutter pub get
-dart run devtools_extensions build_and_copy --source=. --dest="$DEST"
+
+echo "Building extension (release, tree-shake-icons)..."
+flutter build web \
+  --pwa-strategy=offline-first \
+  --release \
+  --tree-shake-icons
+
+echo "Copying build → $DEST_BUILD"
+rm -rf "$DEST_BUILD"
+mkdir -p "$DEST_BUILD"
+cp -R "$SRC_BUILD"/. "$DEST_BUILD"/
+
+# Drop local CanvasKit when the bootstrap is CDN-configured (default).
+# Local files are never fetched at runtime in that case.
+if [[ -f "$DEST_BUILD/flutter_bootstrap.js" ]] &&
+  grep -q 'engineRevision' "$DEST_BUILD/flutter_bootstrap.js" &&
+  ! grep -q 'useLocalCanvasKit":true\|"useLocalCanvasKit": true' "$DEST_BUILD/flutter_bootstrap.js"; then
+  if [[ -d "$DEST_BUILD/canvaskit" ]]; then
+    echo "Pruning unused local canvaskit/ (CDN via engineRevision)..."
+    rm -rf "$DEST_BUILD/canvaskit"
+  fi
+fi
+
+# Debug symbol maps are not needed at runtime.
+find "$DEST_BUILD" -type f \( -name '*.js.symbols' -o -name '*.map' \) -delete
+
+cd "$EXT"
 dart run devtools_extensions validate --package="$ROOT"
-echo "Built DevTools extension → $DEST/build"
+
+echo "Built DevTools extension → $DEST_BUILD ($(du -sh "$DEST_BUILD" | cut -f1))"