Parameterized tests

[seanmrich]

I tried to write a test with swift-testing using parameterized inputs, but it looked like the test values were overwriting each other. I wrote this minimal example to show what I'm seeing:

struct Parameterized {
  @Test(arguments: [23, 42])
  func test(_ input: Int) {
    @Shared(.appStorage("count")) var count = input
    #expect(count == input)
  }
}

One of the two tests always fails because count is set to the other value. I checked the documentation and the discussions but didn't find any answers. Did I miss something obvious?

[mbrandonw]

This is because our Dependencies library, which is what @Shared uses under the hood, does not work with parameterized tests. We are waiting for Swift Testing to support "scoped traits" (coming Swift 6.1) to properly quarantine dependencies on a per-test basis.

There are docs on this, but they are over in the Dependencies library:

https://swiftpackageindex.com/pointfreeco/swift-dependencies/main/documentation/dependencies/testing#Parameterized-Test-cases

[seanmrich]

Gotcha. Thanks!

[vvisionnn]

@mbrandonw I have tried parameterized testing in Xcode 26.0-beta.1, warp all the test operation inside withDependencies block, still failed

[mbrandonw]

Hi @vvisionnn, you will need to provide a minimal project that reproduces the problem in order for anyone to help out.