Sheet dismissal after 1.19 without @Observable

[diogoArgentM]

Description

After updating to 1.19 and everyone version in-between up to the latest 1.21.1 we have had a bug where using the @Dependency(\.dismiss) effect has been causing a glitch animation on dismissal. If the sheet is dismissed by tapping outside of the sheet the bug does not occur.

It seems to be caused by a combination of factors:

• using the deprecated .sheet(store:)
• using the dismiss effect
• using TCA version v1.19.0 or above
• and using presentationDetents

At the moment we are unable to update our project to use @Observable so we are still relying on ViewStore.
I've found a thread with another user that has the same issue
https://pointfreecommunity.slack.com/archives/C04KQQ7NXHV/p1746103346575989

I've also attached a project that reproduces the issue.

Checklist

• I have determined whether this bug is also reproducible in a vanilla SwiftUI project.
• If possible, I've reproduced the issue using the main branch of this package.
• This issue hasn't been addressed in an existing GitHub issue or discussion.

Expected behavior

The sheet to be dismissed without being presented in full initially.

Actual behavior

The sheet seems to be presented in full before dismissal, I've also slowed down animations on the Simulator in order to see it better.

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2025-08-11.at.15.39.15.mp4

Reproducing project

sheet.zip

The Composable Architecture version information

1.21.1

Destination operating system

iOS 18.5

Xcode version information

16.4

Swift Compiler version information

swift-driver version: 1.120.5 Apple Swift version 6.1.2 (swiftlang-6.1.2.1.2 clang-1700.0.13.5)
Target: arm64-apple-macosx15.0

[mluisbrown]

The issue seems to be related to using @PresentationState with .sheet(store:). If you use sheet(isPresented:) passing a Binding created from a ViewStore then the dismissal works as expected.

So that is the workaround if you can't migrate to @Observable yet, although it's kind of an ugly one 😕

[mluisbrown]

Have found that it's definitely related to using store.scope. Even if you use sheet(isPresented:) passing a Binding created from a ViewStore as mentioned above, if you then use IfLetStore(store.scope(state: \.deadBeef, action: \.self), then: { store in }) you will still get the glitch.

If instead you just do an if let sheetState = viewStore.sheetState { SomeView() } then the glitch is gone.

[mluisbrown]

I've been able to isolate the cause of the issue to this PR: #3460

I reverted that PR on a local copy of TCA 1.19.0 and the issue went away.