View modifier not working in test environment

Oct 13, 2025 by wbrum.org 112 views

Describe the Bug

In the app I'm working on, I've encountered a peculiar issue with snapshot testing. I've created a test where I want to assert that for a particular view, the bottom navigation bar is in fact hidden. The app works fine, but for this test, it's not snapshotting correctly. The weird thing for me is that setting store.condition = false simply doesn't work for the test (false = hidden), and the view doesn't change at all. This is leading me to believe that the .toolbar view modifier might not work in the test environment.

To Reproduce

I'll write some pseudo code that represents the problem. Basically, I have a root view with a child TabView that will show other views. Apologies for not pasting working code.

// The view
RootView {
  TabView {
    GeometryReaderWithPerceptionTracking {
      ChildView1{
      }
    }
    .toolbar(store.condition? .visible : .hidden, for: .tabBar)
    .tabItem{}
    ChildView2 {}.tabItem{} //
    ChildView3 {}.tabItem{}
  }
}

Expected Behavior

The expectation is that the snapshot test will show the view without a bottom navigation bar, just like when the app is normally running.

Reality

However, the reality is that the snapshot test shows the bottom navigation bar despite the live experience being different.

Environment

Here are the details of my environment:

Swift-Snapshot-Testing version: 1.17.5
Xcode version: 16.2
Swift version: 5
OS: iOS 16

Possible Causes

There are a few possible causes for this issue:

View modifier not working in test environment: As I mentioned earlier, it seems like the .toolbar view modifier might not work in the test environment. This could be due to the way snapshot testing works or the way the view modifier is implemented.
Store condition not being updated in test: Another possibility is that the store.condition is not being updated in the test environment. This could be due to the way the store is implemented or the way the test is written.
Snapshot testing not capturing the correct state: Finally, it's possible that the snapshot testing is not capturing the correct state of the view. This could be due to the way the snapshot is taken or the way the view is rendered.

Troubleshooting Steps

To troubleshoot this issue, I'll try the following steps:

Check the view modifier implementation: I'll check the implementation of the .toolbar view modifier to see if it's working correctly in the test environment.
Verify the store condition update: I'll verify that the store.condition is being updated correctly in the test environment.
Take a closer look at the snapshot: I'll take a closer look at the snapshot to see if it's capturing the correct state of the view.
Try a different testing approach: If none of the above steps work, I'll try a different testing approach, such as using a different testing framework or writing a custom test.

Conclusion

In conclusion, I've encountered a peculiar issue with snapshot testing where the view with a bottom navigation bar is not being hidden as expected. I've identified a few possible causes for this issue and will try the troubleshooting steps to resolve it. If you have any suggestions or ideas, please let me know in the comments below.

Possible Solutions

Here are a few possible solutions to this issue:

Use a different view modifier: Instead of using the .toolbar view modifier, I could use a different view modifier that works correctly in the test environment.
Update the store condition manually: I could update the store.condition manually in the test environment to see if that resolves the issue.
Use a custom test: I could write a custom test that uses a different approach to test the view with a bottom navigation bar.

Code Snippets

Here are a few code snippets that might be helpful in resolving this issue:

// Check the view modifier implementation
struct ToolbarViewModifier: ViewModifier {
  func body(content: Content) -> some View {
    // implementation
  }
}

// Verify the store condition update
struct Store {
  var condition: Bool = false
}

// Take a closer look at the snapshot
struct SnapshotView: View {
  var body: some View {
    // implementation
  }
}

// Try a different testing approach
struct CustomTest: XCTestCase {
  func testViewWithBottomNavigationBar() {
    // implementation
  }
}

Additional Resources

Here are a few additional resources that might be helpful in resolving this issue:

Swift-Snapshot-Testing documentation: The Swift-Snapshot-Testing documentation provides more information on how to use the framework and troubleshoot issues.
Xcode documentation: The Xcode documentation provides more information on how to use the Xcode testing tools and troubleshoot issues.
Swift documentation: The Swift documentation provides more information on how to use the Swift language and troubleshoot issues.
Snapshot Test Shows My View with a Bottom Navigation Bar When It Should Be Hidden: Q&A ====================================================================================

Q: What is the issue with the snapshot test?

A: The issue with the snapshot test is that it's not capturing the correct state of the view. Specifically, the bottom navigation bar is not being hidden as expected.

Q: Why is the bottom navigation bar not being hidden?

A: There are a few possible reasons why the bottom navigation bar is not being hidden. It could be due to the way the view modifier is implemented, the way the store condition is updated, or the way the snapshot is taken.

Q: How can I troubleshoot this issue?

A: To troubleshoot this issue, you can try the following steps:

Check the view modifier implementation to see if it's working correctly in the test environment.
Verify that the store condition is being updated correctly in the test environment.
Take a closer look at the snapshot to see if it's capturing the correct state of the view.
Try a different testing approach, such as using a different testing framework or writing a custom test.

Q: What are some possible solutions to this issue?

A: Some possible solutions to this issue include:

Using a different view modifier that works correctly in the test environment.
Updating the store condition manually in the test environment.
Writing a custom test that uses a different approach to test the view with a bottom navigation bar.

Q: How can I write a custom test for this issue?

A: To write a custom test for this issue, you can follow these steps:

Create a new test class that inherits from XCTestCase.
Write a test method that uses the custom testing approach.
Use the XCTest framework to assert that the view with a bottom navigation bar is being displayed correctly.

Q: What are some best practices for writing snapshot tests?

A: Some best practices for writing snapshot tests include:

Using a consistent naming convention for your test files and methods.
Keeping your test code organized and easy to read.
Using assertions to verify that the view is being displayed correctly.
Using a testing framework that supports snapshot testing.

Q: How can I use a different testing framework for snapshot testing?

A: To use a different testing framework for snapshot testing, you can follow these steps:

Choose a testing framework that supports snapshot testing, such as XCTest or Quick.
Write a test class that uses the chosen testing framework.
Use the testing framework to write a test method that captures the snapshot of the view.

Q: What are some common pitfalls to avoid when writing snapshot tests?

A: Some common pitfalls to avoid when writing snapshot tests include:

Not using a consistent naming convention for your test files and methods.
Not keeping your test code organized and easy to read.
Not using assertions to verify that the view is being displayed correctly.
Not using a testing framework that supports snapshot testing.

Q: How can I debug snapshot tests?

A: To debug snapshot tests, you can follow these steps:

Use the testing framework's built-in debugging tools to identify the issue.
Use a debugger to step through the test code and identify the issue.
Use a logging framework to log the test results and identify the issue.

Q: What are some best practices for maintaining snapshot tests?

A: Some best practices for maintaining snapshot tests include:

Regularly updating the snapshot to reflect changes to the view.
Using a version control system to track changes to the test code.
Using a testing framework that supports snapshot testing.
Keeping the test code organized and easy to read.

Q: How can I automate the process of maintaining snapshot tests?

A: To automate the process of maintaining snapshot tests, you can follow these steps:

Use a testing framework that supports snapshot testing.
Use a version control system to track changes to the test code.
Use a continuous integration tool to automate the process of running the tests.
Use a logging framework to log the test results and identify issues.