How to get the tag of a view in an Espresso test?

I am working in some end to end test using Espresso.
In the test I need to know the user id (because I need to call one endpoint that mocks some external party).
To get the user id, I was thinking about setting it as a tag in a view and get the tag with Espresso.

Is there a way to do that?

I only find ways to get a view by tag, but not actually getting the content of the tag.

Thanks for your help.

You can use the following extension function:

inline fun <reified T : Any> ViewInteraction.getTag(): T? {
    var tag: T? = null
    perform(object : ViewAction {
        override fun getConstraints() = ViewMatchers.isAssignableFrom(View::class.java)

        override fun getDescription() = "Get tag from View"

        override fun perform(uiController: UiController, view: View) {
            when (val viewTag = view.tag) {
                is T -> tag = viewTag
                else -> error("The tag cannot be casted to the given type!")
            }
        }
    })
    return tag
}

To the get tag like:

@Test
fun myTest() {
    ...
    val userId = onView(withId(R.id.myView)).getTag<String>()
    ...
}