Fix remaining `unawaited_futures` violations by victorsanni · Pull Request #193135 · flutter/flutter

victorsanni · 2026-09-22T00:00:24Z

Resolves the remaining unawaited_futures violations across

packages/flutter/lib/,
packages/flutter_driver/,
packages/integration_test/,
dev/, and
non-frozen tests in packages/flutter/test/{animation,foundation,services,widgets}

in preparation for enabling unawaited_futures repository-wide (#193125).

Call sites use await, unawaited(...), or // ignore: unawaited_futures (where stack trace line/column expectations must be preserved).

Mostly Dart SDK functions are causing this. Missed when working on this earlier.

Part of #168555

Pre-launch Checklist

I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
I read the [Tree Hygiene] wiki page, which explains my responsibilities.
I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
I signed the [CLA].
I listed at least one issue that this PR fixes in the description above.
I updated/added relevant documentation (doc comments with ///).
I added new tests to check the change I am making, or this PR is [test-exempt].
I followed the [breaking change policy] and added [Data Driven Fixes] where supported.
All existing and new tests are passing.

…flutter#168555)

gemini-code-assist

Code Review

This pull request wraps numerous asynchronous calls in unawaited or adds linter ignore comments to address the unawaited_futures rule across various tests, benchmarks, and framework files. However, several critical issues were identified where using unawaited instead of await introduces bugs or regressions. Specifically, not awaiting HttpOverrides.runZoned in tests can cause them to pass prematurely without executing assertions, while bypassing await on window resizing, file I/O, and benchmark recording calls can lead to race conditions, missing output files, and inaccurate performance measurements.

gemini-code-assist · 2026-09-22T00:02:33Z

+          unawaited(
+            _profile!.recordAsync('sceneBuildDuration', () async {
+              final Scene scene = sceneBuilder.build();
+              unawaited(
+                _profile!.recordAsync('windowRenderDuration', () async {
+                  // On the web, render is asynchronous.
+                  await (PlatformDispatcher.instance as dynamic).render(scene);
+                }, reported: false),
+              );
+            }, reported: false),
+          );


Not awaiting the nested recordAsync calls means that drawFrameDuration will complete and be recorded before the asynchronous sceneBuildDuration and windowRenderDuration (which performs the actual async render) have finished. This results in inaccurate benchmark measurements. They should be awaited instead of wrapped in unawaited.

await _profile!.recordAsync('sceneBuildDuration', () async { final Scene scene = sceneBuilder.build(); await _profile!.recordAsync('windowRenderDuration', () async { // On the web, render is asynchronous. await (PlatformDispatcher.instance as dynamic).render(scene); }, reported: false); }, reported: false);

I was thinking the same thing while reading this code (thought without having tried this myself).

yup agree with the bot for drawFrameDuration, but the inner most await will cause sceneBuildDuration to also include windowRenderDuration, which I am not sure whether that is something we want. cc @mdebbar do you know if sceneBuildDuration should include windowRenderDuration? if not, we will need to break the async method into 2

I agree with @chunhtai . I propose the following way:

late final Scene scene; _profile!.record('sceneBuildDuration', () { scene = sceneBuilder.build(); }, reported: false); await _profile!.recordAsync('windowRenderDuration', () async { // On the web, render is asynchronous. await (PlatformDispatcher.instance as dynamic).render(scene); }, reported: false);

Because sceneBuildDuration should only record sceneBuilder.build and should not include windowRenderDuration in a nested way.

However, this kind of change is out of the scope of a refactoring PR. I suggest we remove changing this file from this PR and instead do it in a different PR.

I can split it out of this PR.

… numbers

justinmc

My default approach for these is always to prefer await to ignoring the lint rule where possible, so I left some comments asking about doing that. Did you try these with await already? I imagine lots of them don't have await for a reason, but I'd try them out.

justinmc · 2026-09-23T18:50:41Z

+          unawaited(
+            _profile!.recordAsync('sceneBuildDuration', () async {
+              final Scene scene = sceneBuilder.build();
+              unawaited(
+                _profile!.recordAsync('windowRenderDuration', () async {
+                  // On the web, render is asynchronous.
+                  await (PlatformDispatcher.instance as dynamic).render(scene);
+                }, reported: false),
+              );
+            }, reported: false),
+          );


I was thinking the same thing while reading this code (thought without having tried this myself).

justinmc · 2026-09-23T18:59:38Z

+      unawaited(
+        showDialog<void>(


I feel like the _showApiDocumentation might make more sense if it returned this Future here. But since it's a private API in a demo, it might not be worth it to change given how it's actually used. I think it's fine either way.

What is our plan for the references of material in the flutter_gallery? Since we're going to remove material at some point (whether by changing it to material_ui or something non-material), the showDialog here will be replaced by some function that is marked with awaitNotRequired, and thus this unwaited will be awkward to be left here.

I think I can just await here.

chunhtai · 2026-09-23T19:40:12Z

+          unawaited(
+            _profile!.recordAsync('sceneBuildDuration', () async {
+              final Scene scene = sceneBuilder.build();
+              unawaited(
+                _profile!.recordAsync('windowRenderDuration', () async {
+                  // On the web, render is asynchronous.
+                  await (PlatformDispatcher.instance as dynamic).render(scene);
+                }, reported: false),
+              );
+            }, reported: false),
+          );


yup agree with the bot for drawFrameDuration, but the inner most await will cause sceneBuildDuration to also include windowRenderDuration, which I am not sure whether that is something we want. cc @mdebbar do you know if sceneBuildDuration should include windowRenderDuration? if not, we will need to break the async method into 2

chunhtai · 2026-09-23T19:41:05Z

    WidgetTester tester,
  ) async {
-    Future<void>.error('Who lives, who dies, who tells your story?');
+    Future<void>.error('Who lives, who dies, who tells your story?'); // ignore: unawaited_futures


why using ignore instead of unawaited()?

/dev/automated_tests/integration_test/exception_handling_expectation.txt is regex matching the exact stacktrace frame, line and column numbers. So if I change it to unawaited the tests will fail or the expected error will be suppressed.

we should either update the text expectation, or add some comments on why we use ignore here.

dkwingsmt · 2026-09-23T20:36:00Z

+      unawaited(
+        showDialog<void>(


What is our plan for the references of material in the flutter_gallery? Since we're going to remove material at some point (whether by changing it to material_ui or something non-material), the showDialog here will be replaced by some function that is marked with awaitNotRequired, and thus this unwaited will be awkward to be left here.

…der.dart

…ures-blockers

…ictorsanni/flutter into fix-unawaited-futures-blockers

… reassemble in widget_inspector_test.dart

justinmc

LGTM 👍 Now it looks more like what I was expecting in terms of when to add await and when to ignore. Thanks!

chunhtai

LGTM, one minor suggestion

chunhtai · 2026-09-24T17:29:53Z

    WidgetTester tester,
  ) async {
-    Future<void>.error('Who lives, who dies, who tells your story?');
+    Future<void>.error('Who lives, who dies, who tells your story?'); // ignore: unawaited_futures


we should either update the text expectation, or add some comments on why we use ignore here.

… showDialog in navigator_test

justinmc

ReLGTM 👍

…erRecorder (#193260) Splits out the `dev/benchmarks/macrobenchmarks/lib/src/web/recorder.dart` fix from #193135 per review discussion (#193135 (comment)). Previously, `SceneBuilderRecorder.onDrawFrame` nested `_profile!.recordAsync('windowRenderDuration', ...)` inside synchronous `_profile!.record('sceneBuildDuration', ...)` without awaiting `recordAsync`, which both triggered `unawaited_futures` and caused `sceneBuildDuration` to include the synchronous portion of `windowRenderDuration`. This PR un-nests the two recordings and makes `onDrawFrame` `async` so `sceneBuildDuration` only measures `sceneBuilder.build()` and `windowRenderDuration` is properly awaited.

Fix remaining unawaited_futures violations across non-frozen codebase (…

5ce41fe

…flutter#168555)

flutter-dashboard Bot added the CICD Run CI/CD label Sep 22, 2026

gemini-code-assist Bot reviewed Sep 22, 2026

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victorsanni changed the title ~~Fix remaining unawaited_futures violations across non-frozen codebase~~ Fix remaining unawaited_futures violations Sep 22, 2026

victorsanni requested a review from dkwingsmt September 22, 2026 00:24

victorsanni added 2 commits September 21, 2026 18:08

Use end-of-line ignore in widget_inspector_test.dart to preserve line…

3190138

… numbers

Merge branch 'master' into fix-unawaited-futures-blockers

026a43e

victorsanni requested review from chunhtai and justinmc September 23, 2026 18:47

Merge branch 'master' into fix-unawaited-futures-blockers

9815c25

justinmc reviewed Sep 23, 2026

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chunhtai reviewed Sep 23, 2026

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dkwingsmt reviewed Sep 23, 2026

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victorsanni added 4 commits September 23, 2026 18:17

Address review feedback: await futures where safe and split out recor…

4b1c53d

…der.dart

Merge remote-tracking branch 'upstream/master' into fix-unawaited-fut…

d15bcc0

…ures-blockers

Merge branch 'fix-unawaited-futures-blockers' of https://github.com/v…

8ddcccb

…ictorsanni/flutter into fix-unawaited-futures-blockers

Fix unawaited_return_in_try_block in platform_view.dart and FakeAsync…

f122a1d

… reassemble in widget_inspector_test.dart

victorsanni mentioned this pull request Sep 24, 2026

Un-nest sceneBuildDuration and windowRenderDuration in web SceneBuilderRecorder #193260

Merged

victorsanni requested review from chunhtai, dkwingsmt and justinmc September 24, 2026 01:29

justinmc previously approved these changes Sep 24, 2026

View reviewed changes

chunhtai previously approved these changes Sep 24, 2026

View reviewed changes

Address review feedback: clarify exception handling ignores and await…

c75a6ba

… showDialog in navigator_test

victorsanni dismissed stale reviews from chunhtai, dkwingsmt, and justinmc via c75a6ba September 24, 2026 20:09

Merge branch 'master' into fix-unawaited-futures-blockers

01c534c

victorsanni requested review from chunhtai, dkwingsmt and justinmc September 24, 2026 20:17

dkwingsmt approved these changes Sep 24, 2026

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victorsanni added the autosubmit Merge PR when tree becomes green via auto submit App label Sep 24, 2026

justinmc approved these changes Sep 24, 2026

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auto-submit Bot added this pull request to the merge queue Sep 25, 2026

Merged via the queue into flutter:master with commit d253af9 Sep 25, 2026
23 checks passed

flutter-dashboard Bot removed the autosubmit Merge PR when tree becomes green via auto submit App label Sep 25, 2026

victorsanni deleted the fix-unawaited-futures-blockers branch September 25, 2026 18:38

engine-flutter-autoroll mentioned this pull request Sep 28, 2026

Roll Flutter from 4fcd90be0045 to 9345dd20564f (216 revisions) flutter/packages#13055

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