Override accessibility environment values in SwiftUI snapshot tests?

Question

I'm writing snapshot tests for SwiftUI views using the Point-Free snapshot test library. I'd like to test that my views respond correctly to the following SwiftUI environment properties:

• accessibilityDifferentiateWithoutColor
• accessibilityReduceTransparency
• accessibilityReduceMotion
• accessibilityInvertColors

How can I override these values in my tests?

Answer 1

There are public-but-undocumented, underscored versions of these symbols that can be used to override their values in tests:

• _accessibilityDifferentiateWithoutColor
• _accessibilityReduceTransparency
• _accessibilityReduceMotion
• _accessibilityInvertColors

Usage:

someView
    .environment(\._accessibilityShowButtonShapes, true)

It is my understanding that these values are intentionally provided by Apple for testing purposes.