How to check background color of the XCUIElement in UI test cases??

Question

I am working on one issue where I need to change the Textfield's background color to the white color. I wanted to add the UI test case for it to check if background color of the XCUIElement(i.e Textfield) is white color or not. I searched for it but didn't not find any useful answer on it. I wanted to know if it is even possible check against background color in the UITest Cases.

I was going through Matt's answer, but didn't get clear idea.

https://stackoverflow.com/a/37754840/3278326

Thoughts?

Answer 1

Like guys replied in comments, we can't do it by UI tests, but I think we still have 2 ways to achieve this:

1. Snapshot Tests:

    import SnapshotTesting
    ...
    func test_view_matchesSnapshot() {
        let view = makeYourView()
        assertSnapshot(matching: view, as: .wait(for: 1.5, on: .image))
    }
   

2. Unit Tests:

    func test_view_shouldHaveTextFieldWithExpectedBackgroundColor() throws {
        let view = makeYourView()
   
        let textFieldBackgroundColor = try XCTUnwrap(
            view.textField.backgroundColor, 
            "textField.backgroundColor is nil"
        )
   
        let expectedTextFieldBackgroundColor = UIColor.white
   
        XCTAssertEqual(
            textFieldBackgroundColor.toHexString(),
            expectedTextFieldBackgroundColor.toHexString(),
            "textField doesn't have expected backgroundColor"
        )
    }
   

*Utility hex getters to compare two UIColors can be found here

**If your textField is private, then you can use this great solution and our unit test should look like this:

    func test_view_shouldHaveTextFieldWithExpectedBackgroundColor() throws {
        let view = makeYourView()

        let textField = try XCTUnwrap(
            YourViewMirror(reflecting: view).textField, 
            "Can't find textField property"
        )

        let textFieldBackgroundColor = try XCTUnwrap(
            textField.backgroundColor, 
            "textField.backgroundColor is nil"
        )

        let expectedTextFieldBackgroundColor = UIColor.white

        XCTAssertEqual(
            textFieldBackgroundColor.toHexString(),
            expectedTextFieldBackgroundColor.toHexString(),
            "textField doesn't have expected backgroundColor"
        )
    }

where

final class YourViewMirror: MirrorObject {
    init(reflecting yourView: YourView) {
        super.init(reflecting: yourView)
    }
    var textField: UITextField? {
        extract()
    }
}

and

class MirrorObject {
    let mirror: Mirror
    init(reflecting: Any) {
        self.mirror = Mirror(reflecting: reflecting)
    }

    func extract<T>(variableName: StaticString = #function) -> T? {
        return mirror.descendant("\(variableName)") as? T
    }
}