Readability

We like the syntax that Kakao applies to write UI tests. This wrapper over Espresso uses the Kotlin DSL approach, that makes the code significantly shorter and more readable. See the difference:

Espresso:

@Test
fun testFirstFeature() {
    onView(withId(R.id.toFirstFeature))
        .check(ViewAssertions.matches(
               ViewMatchers.withEffectiveVisibility(
                       ViewMatchers.Visibility.VISIBLE)))
    onView(withId(R.id.toFirstFeature)).perform(click())
}

Kakao:

@Test
fun testFirstFeature() {
    mainScreen {
        toFirstFeatureButton {
            isVisible()
            click()
        }
    }
}

We used the same approach to develop our own wrapper over UI Automator, and we called it Kautomator. Take a look at the code below:

UI Automator:

val instrumentation: Instrumentation = InstrumentationRegistry.getInstrumentation()
val uiDevice = UiDevice.getInstance(instrumentation)
val uiObject = uiDevice.wait(
    Until.findObject(
        By.res(
            "com.kaspersky.kaspresso.sample_kautomator",
            "editText"
        )
    ),
    2_000
)
uiObject.text = "Kaspresso"
assertEquals(uiObject.text, "Kaspresso")

Kautomator:

MainScreen {
    simpleEditText {
        replaceText("Kaspresso")
        hasText("Kaspresso")
    }
}

Since Kakao and Kautomator provide almost identical APIs, you don’t have to care about what is under the hood of your tests, either Espresso or UI Automator. With Kaspresso, you write tests in the same style for both.

However, Kakao and Kautomator themselves don't help you to see the relation between the test and the corresponding test case. Also, a long test often becomes a giant piece of code that is impossible to split into smaller parts. That's why we have created an additional Kotlin DSL that allows you to read your test more easily.

See the example below:

@Test
fun shouldPassOnNoInternetScanTest() =
    beforeTest {
        activityTestRule.launchActivity(null)
        // some things with the state
    }.afterTest {
        // some things with the state
    }.run {
        step("Open Simple Screen") {
            MainScreen {
                nextButton {
                    isVisible()
                    click()
                }
            }
        }
        step("Click button_1 and check button_2") {
            SimpleScreen {
                button1 {
                    click()
                }
                button2 {
                    isVisible()
                }
            }
        }
        step("Click button_2 and check edit") {
            SimpleScreen {
                button2 {
                    click()
                }
                edit {
                    flakySafely(timeoutMs = 7000) { isVisible() }
                    hasText(R.string.text_edit_text)
                }
            }
        }
        step("Check all possibilities of edit") {
            scenario(
                CheckEditScenario()
            )
        }
    }

Stability

Sometimes your UI test passes ten times, then breaks on the eleventh attempt for some mysterious reason. It’s called flakiness.

The most popular reason for flakiness is the instability of the UI tests libraries, such as Espresso and UI Automator. To eliminate this instability, Kaspresso uses DSL wrappers and interceptors.

UI test libraries acceleration

Let’s watch some short video that shows the difference between the original UI Automator (on the right) and the accelerated one (on the left).

Here is a short explanation of why it is possible.

Interceptors

We developed Kaspresso behavior interceptors on the base of Kakao/Kautomator Interceptors to catch failures.

Thanks to interceptors, you can do a lot of useful things, such as:

• add custom actions to each framework operation like writing a log or taking a screenshot;
• overcome flaky operations by re-running failed actions, scrolling the parent layout or closing the android system dialog;

and many more (see the manual).

Writing readable logs

Kaspresso writes its own logs, detailed and readable:

Ability to call ADB commands

Espresso and UI Automator don't allow to call ADB commands from inside a test. To fix this problem, we developed AdbServer (see the wiki).

Ability to work with Android System

You can use Kaspresso classes to work with Android System.

For example, with the Device class you can:

• push/pull files,
• enable/disable network,
• give permissions like a user does,
• emulate phone calls,
• take screenshots,
• enable/disable GPS,
• set geolocation,
• enable/disable accessibility,
• change the app language,
• collect and parse the logcat output.

(see more about the Device class).

Features screenshotting

If you develop an application that is available across the world, you have to localize it into different languages. When UI is localized, it’s important for the translator to see the context of a word or a phrase, that is the specific screen.

With Kaspresso, translators can automatically take a screenshot of any screen. It’s incredibly fast, even for legacy screens, and you don't have to refactor or mock anything (see the manual).

Configurability

You can tune any part of Kaspresso (read more).

Robolectric support

You can run your UI-tests on the JVM environment. Additionally, almost all interceptors improving stability, readability and other will work. Read more.

Allure support

Kaspresso can generate very detailed Allure-reports for each test: More information is available here.

Jetpack Compose support

Now, you can write your Kaspresso tests for Jetpack Compose screens! DSL and all principles are the same. So, you will not see any difference between tests for View screens and for Compose screens. More information is available here.