key

Creates an Expect for the property Map.Entry.key of the subject of this expectation, so that further fluent calls are assertions about it.

val entry = mapOf(1 to "a").entries.first()

expect(entry)
    .key          // subject here is of type Int (actually 1)
    .toEqual(1)

fails {
    expect(entry)
        .key             // subject here is of type Int (actually 1)
        .toEqual(2)      // fails
        .toBeLessThan(0) // not evaluated/reported because `toEqual` already fails
    //                      use `.key { ... }` if you want that all assertions are evaluated
}

Return
The newly created Expect for the extracted feature.

Expects that the property Map.Entry.key of the subject of this expectation holds all assertions the given assertionCreator creates for it and returns an Expect for the current subject of this expectation.

val entry = mapOf(1 to "a").entries.first()

expect(entry).key {  // subject inside this block is of type Int (actually 1)
    toEqual(1)
} // subject here is back to type Map.Entry<Int, String>

fails {
    expect(entry).key {  // subject inside this block is of type Int (actually 1)
        toEqual(2)       // fails
        toBeLessThan(0)  // still evaluated even though `toEqual` already fails,
        //                  use `.key.` if you want a fail fast behaviour
    }
}

Return
an Expect for the subject of this expectation.