I would suggest making the naming schema configurable.
The package of our setup is always the same which makes it unnecessary clutter in the filename.

@Chrisjc28 (or anyone) mind elaborating on the "why"? Would help prioritizing if some use cases were provided.

We had a recent issue where the memory reference was being used in the name of the snapshot, when running locally all of our tests worked fine. However when running in our CI the test would use a different memory reference in the name causing them to fail. This is a niche issue but if we were able to have more control over what the file name was this wouldn't have happened. We have put something in place as a temporary fix but it has place a code smell in our project i would rather not have.

I've seen this before with usages of TestParameterInjector with custom provided values. In those cases, providing a toString method or implementing as a data class is the suggested fix.

In our case we have used a secondary constructor and it's being changed to a data class, however there is no benefit for us to have the data class.

An example of the class we are using in our test is -

sealed Class AppState {
        object: Loading,
        data class Success(val data: Any)
        data class Error(val error: Any)
} 

For us converting loading to a data class has no benefit and makes us have to make use of a secondary constructor just so we don't have to and parentheses to every instance of loading.

The suggestion of using toString would you mean to implement that in the loading object itself?

Being able to specify a custom filename would be great, instead of the hard-coded list which includes things like packagename

internal fun Snapshot.toFileName(
  delimiter: String = "_",
  extension: String
): String {
  val formattedLabel = if (name != null) {
    "$delimiter${name.toLowerCase(Locale.US).replace("\\s".toRegex(), delimiter)}"
  } else {
    ""
  }
  return "${testName.packageName}${delimiter}${testName.className}${delimiter}${testName.methodName}$formattedLabel.$extension"
}

Being able to provide a custom filename would allow me to remove the packageName part, which is the same for all my tests e.g. com.example.tests.ui.paparazzi, I only really need className and methodName.

I would like this, the excessive name also makes it truncate in github and makes it hard to find files in finder.