[flutter_tools] Reload widget-preview when data assets change - #193437

…mpty (flutter#193434)

When `flutterManifest.isEmpty` (for example, a `pubspec.yaml` without a
`flutter:` section), `ManifestAssetBundle.build` previously returned
early with an empty `AssetManifest.bin`, ignoring any data assets
produced by build/link hooks (`flutterHookResult.dataAssets`).

Bug:

* flutter#146264

### Changes
- Only short-circuit with an empty manifest in
`ManifestAssetBundle.build` when both `flutterManifest.isEmpty` and
`flutterHookResult?.dataAssets.isEmpty ?? true`.
- Skip `computeTransitiveDependencies` when `flutterManifest.isEmpty`.
- Add a unit test in `asset_bundle_test.dart` verifying that data assets
from hooks are bundled when `pubspec.yaml` is empty.

### PR Stack
| # | PR | Branch | Commit |
| :-: | :--- | :--- | :--- |
| **1** | **👉 flutter#193434 (this PR)**
| `data-assets-empty-pubspec` |
flutter@62199c4
|
| 2 | flutter#193435 |
`data-assets-flutter-test` |
flutter@25be1ab
|
| 3 | flutter#193436 |
`data-assets-dev-dependencies-release-test` |
flutter@79abad9
|
| 4 | flutter#193437 |
`data-assets-widget-preview` |
flutter@98f1001
|

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant in-code documentation (doc comments with
`///`).
- [x] If this PR introduces a new feature or capability, I created and
linked a website documentation issue or PR in [flutter/website] (or
verified none is needed).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

…r#193435)

Previously, `flutter test` ran native assets hooks via
`TestCompilerNativeAssetsBuilder.build(buildInfo)`, which only returned
the `NativeAssetsManifest.json` URI and discarded the
`FlutterHookResult` containing hook-generated data assets.

Bug:

* flutter#146264

### Changes
- Add `buildWithHookResult` to `TestCompilerNativeAssetsBuilder`
returning both `nativeAssetsManifest` and `flutterHookResult`.
- Pass `flutterHookResult` to `_buildTestAsset` / `assetBundle.build` in
`TestCommand`.
- Update `TestCommand._needsRebuild` to check if bundled asset files
exist on disk, guard `pub.existsSync()`, and check
`flutterHookResult.dependencies` modification timestamps.
- Add a hermetic test in `test_test.dart` verifying that `flutter test`
bundles data assets from hooks into `build/unit_test_assets`.

### PR Stack
| # | PR | Branch | Commit |
| :-: | :--- | :--- | :--- |
| 1 | flutter#193434 |
`data-assets-empty-pubspec` |
flutter@62199c4
|
| **2** | **👉 flutter#193435 (this PR)**
| `data-assets-flutter-test` |
flutter@390c757
|
| 3 | flutter#193436 |
`data-assets-dev-dependencies-release-test` |
flutter@cca04e9
|
| 4 | flutter#193437 |
`data-assets-widget-preview` |
flutter@0a5a8e9
|

> **Note:** This PR is stacked on
flutter#193434. To review only this PR's
diff before the base PR lands, view commit
flutter@390c757.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant in-code documentation (doc comments with
`///`).
- [x] If this PR introduces a new feature or capability, I created and
linked a website documentation issue or PR in [flutter/website] (or
verified none is needed).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

…n tests (flutter#193436)

When running release-mode tests (such as `flutter test integration_test
--release`), `createFlutterNativeAssetsBuildRunner` previously set
`includeDevDependencies = !buildMode.isRelease`, which excluded hooks
from `dev_dependencies`.

Bug:

* flutter#146264

### Changes
- Check `_isTestTarget(environment)` (whether `kTargetFile` is under
`integration_test/`, `test_driver/`, or `test/`) so
`includeDevDependencies` is `true` for test targets even in release
mode.
- Add a unit test in `native_assets_test.dart` verifying
`includeDevDependencies` is `false` for `lib/main.dart` in release mode
and `true` for `integration_test/app_test.dart`, `test_driver/app.dart`,
and `test/app_test.dart`.

### PR Stack
| # | PR | Branch | Commit |
| :-: | :--- | :--- | :--- |
| 1 | flutter#193434 |
`data-assets-empty-pubspec` |
flutter@ab37f42
|
| 2 | flutter#193435 |
`data-assets-flutter-test` |
flutter@4956c97
|
| **3** | **👉 flutter#193436 (this PR)**
| `data-assets-dev-dependencies-release-test` |
flutter@596124d
|
| 4 | flutter#193437 |
`data-assets-widget-preview` |
flutter@bd246d9
|

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant in-code documentation (doc comments with
`///`).
- [x] If this PR introduces a new feature or capability, I created and
linked a website documentation issue or PR in [flutter/website] (or
verified none is needed).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

flutter/flutter@426be96...5c7e45a

2026-10-15 [email protected] [web_paragraph] Honor TextHeightBehavior.leadingDistribution and default to proportional (flutter/flutter#193736)
2026-10-15 [email protected] Roll Skia from 79a00d7c4898 to d131b7789482 (2 revisions) (flutter/flutter#194446)
2026-10-15 [email protected] Roll Dart SDK from b8ffa9233096 to 84686ea04815 (1 revision) (flutter/flutter#194442)
2026-10-15 [email protected] Roll Dart SDK from e81af2dac9d1 to b8ffa9233096 (1 revision) (flutter/flutter#194432)
2026-10-15 [email protected] Roll Skia from ef24b8f87a2a to 79a00d7c4898 (4 revisions) (flutter/flutter#194431)
2026-10-15 [email protected] Roll Skia from 48c51004ee4e to ef24b8f87a2a (1 revision) (flutter/flutter#194427)
2026-10-15 [email protected] Roll Dart SDK from 6b50116630d0 to e81af2dac9d1 (5 revisions) (flutter/flutter#194422)
2026-10-15 [email protected] Roll Skia from b1be97266d3a to 48c51004ee4e (10 revisions) (flutter/flutter#194421)
2026-10-15 [email protected] RawAutocomplete: Fix focusNode listener mismatch in didUpdateWidget/dispose (flutter/flutter#190686)
2026-10-14 [email protected] [flutter_tools] Wait for iOS simulator log stream before launch (flutter/flutter#193142)
2026-10-14 [email protected] Move Material/Cupertino PRs from design triage to framework triage (flutter/flutter#194244)
2026-10-14 [email protected] refactor(flutter_tools): share FlutterCommand options and OptionBundles (flutter/flutter#194356)
2026-10-14 [email protected] Roll pub packages (flutter/flutter#194413)
2026-10-14 [email protected] Add ContextMenuButtonKind (flutter/flutter#193528)
2026-10-14 [email protected] Split SwiftPM plugin into multiple products (flutter/flutter#193521)
2026-10-14 [email protected] Roll Skia from 43d707a3be0e to b1be97266d3a (8 revisions) (flutter/flutter#194392)
2026-10-14 [email protected] Roll pub packages (flutter/flutter#194398)
2026-10-14 [email protected] [flutter_tools] Migrate AndroidSdk and AndroidStudio away from globals (flutter/flutter#193650)
2026-10-14 [email protected] [flutter_tools] Reload widget-preview when data assets change (flutter/flutter#193437)
2026-10-14 [email protected] [flutter tool] suppress sub-tool analytics during first run (flutter/flutter#194320)
2026-10-14 [email protected] Roll Skia from acde3755d2e2 to 43d707a3be0e (1 revision) (flutter/flutter#194385)

If this roll has caused a breakage, revert this CL and set the roller
to dry run mode using the controls here:
https://autoroll.skia.org/r/flutter-packages
Please CC [email protected],[email protected] on the revert to ensure that a human
is aware of the problem.

To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
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Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

…r#193435)

Previously, `flutter test` ran native assets hooks via
`TestCompilerNativeAssetsBuilder.build(buildInfo)`, which only returned
the `NativeAssetsManifest.json` URI and discarded the
`FlutterHookResult` containing hook-generated data assets.

Bug:

* flutter#146264

### Changes
- Add `buildWithHookResult` to `TestCompilerNativeAssetsBuilder`
returning both `nativeAssetsManifest` and `flutterHookResult`.
- Pass `flutterHookResult` to `_buildTestAsset` / `assetBundle.build` in
`TestCommand`.
- Update `TestCommand._needsRebuild` to check if bundled asset files
exist on disk, guard `pub.existsSync()`, and check
`flutterHookResult.dependencies` modification timestamps.
- Add a hermetic test in `test_test.dart` verifying that `flutter test`
bundles data assets from hooks into `build/unit_test_assets`.

### PR Stack
| # | PR | Branch | Commit |
| :-: | :--- | :--- | :--- |
| 1 | flutter#193434 |
`data-assets-empty-pubspec` |
flutter@62199c4
|
| **2** | **👉 flutter#193435 (this PR)**
| `data-assets-flutter-test` |
flutter@390c757
|
| 3 | flutter#193436 |
`data-assets-dev-dependencies-release-test` |
flutter@cca04e9
|
| 4 | flutter#193437 |
`data-assets-widget-preview` |
flutter@0a5a8e9
|

> **Note:** This PR is stacked on
flutter#193434. To review only this PR's
diff before the base PR lands, view commit
flutter@390c757.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant in-code documentation (doc comments with
`///`).
- [x] If this PR introduces a new feature or capability, I created and
linked a website documentation issue or PR in [flutter/website] (or
verified none is needed).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

…n tests (flutter#193436)

When running release-mode tests (such as `flutter test integration_test
--release`), `createFlutterNativeAssetsBuildRunner` previously set
`includeDevDependencies = !buildMode.isRelease`, which excluded hooks
from `dev_dependencies`.

Bug:

* flutter#146264

### Changes
- Check `_isTestTarget(environment)` (whether `kTargetFile` is under
`integration_test/`, `test_driver/`, or `test/`) so
`includeDevDependencies` is `true` for test targets even in release
mode.
- Add a unit test in `native_assets_test.dart` verifying
`includeDevDependencies` is `false` for `lib/main.dart` in release mode
and `true` for `integration_test/app_test.dart`, `test_driver/app.dart`,
and `test/app_test.dart`.

### PR Stack
| # | PR | Branch | Commit |
| :-: | :--- | :--- | :--- |
| 1 | flutter#193434 |
`data-assets-empty-pubspec` |
flutter@ab37f42
|
| 2 | flutter#193435 |
`data-assets-flutter-test` |
flutter@4956c97
|
| **3** | **👉 flutter#193436 (this PR)**
| `data-assets-dev-dependencies-release-test` |
flutter@596124d
|
| 4 | flutter#193437 |
`data-assets-widget-preview` |
flutter@bd246d9
|

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant in-code documentation (doc comments with
`///`).
- [x] If this PR introduces a new feature or capability, I created and
linked a website documentation issue or PR in [flutter/website] (or
verified none is needed).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

…r#193437)

Previously, `PreviewDetector` and `LspPreviewDetector` ignored
modifications to non-Dart files (and Dart files outside the analysis
context, such as hook scripts), and
`FlutterHookResult._wasAnyFileModifiedSince` did not treat deleted files
(`FileSystemEntityType.notFound`) as modified.

Bug:

* flutter#146264

### Changes
- Add `onNonDartFileChangeDetected` callback to `PreviewDetector` and
`LspPreviewDetector`, wired up in `WidgetPreviewStartCommand` to trigger
a preview app restart when `assetBundle.needsBuild()` is `true`.
- Treat `FileSystemEntityType.notFound` as modified in
`FlutterHookResult._wasAnyFileModifiedSince`.
- Update `lsp_preview_detector_test.dart` and `asset_bundle_test.dart`.

### PR Stack
| # | PR | Branch | Commit |
| :-: | :--- | :--- | :--- |
| 1 | flutter#193434 |
`data-assets-empty-pubspec` |
flutter@ab37f42
|
| 2 | flutter#193435 |
`data-assets-flutter-test` |
flutter@4956c97
|
| 3 | flutter#193436 |
`data-assets-dev-dependencies-release-test` |
flutter@416d09a
|
| **4** | **👉 flutter#193437 (this PR)**
| `data-assets-widget-preview` |
flutter@431b96e
|

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant in-code documentation (doc comments with
`///`).
- [x] If this PR introduces a new feature or capability, I created and
linked a website documentation issue or PR in [flutter/website] (or
verified none is needed).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.