Inconsistent Lifecycle Timing of .introspect Execution on iOS 17 vs iOS 18

[dasilvans]

Description

Hi, I am observing differences in the lifecycle timing of .introspect execution when upgrading from iOS 17 to iOS 18. Specifically, the order in which .introspect is executed relative to other view modifiers or lifecycle events (like .task) appears to have changed.

Here’s an example (though this issue also arises in other contexts):

ScrollView(.horizontal) {
    // Scroll view content
}
.introspect(.scrollView, on: .iOS(.v16...)) { scrollView in
    // Setup UIScrollView
}
.task {
    // Logic dependent on UIScrollView setup
}

• iOS 17 Behavior: .introspect is called earlier in the view’s lifecycle, so the UIScrollView setup is completed before .task is executed.
• iOS 18 Behavior: .task is executed first, and .introspect is called afterward, leading to cases where the UIScrollView is not yet set up when the .task logic runs.

This timing inconsistency creates challenges for logic that depends on .introspect being executed before other lifecycle events.

Checklist

• I have read the README before submitting this report.
• This issue hasn't been addressed in an existing GitHub issue or discussion.

Expected behavior

The .introspect modifier should ideally execute consistently at the same lifecycle stage across iOS versions, ensuring predictable behavior.

Questions
1. Is this a known change in the way .introspect interacts with SwiftUI lifecycle events in iOS 18?
2. Are there any suggested patterns or best practices to ensure that .introspect executes at the desired lifecycle stage, regardless of the iOS version?
3. Has anyone else experienced similar timing inconsistencies with .introspect or other modifiers, and if so, how did you address them?

Thank you for your help!

Actual behavior

No response

Steps to reproduce

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Version information

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Destination operating system

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Xcode version information

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Swift Compiler version information

No response