SCREENSHOT TESTING NIKOS LINAKIS - CHRISTOFOROS FILIPPOU ANDROID TEAM @XM TESTING THE UI AND BEYOND 

TESTING • Unit tests for business logic • UI tests for business or presentation logic • Robolectric for asserting view state • Espresso for interactions, layout 

VISUAL TESTING METHOD SCREENSHOT TESTING 

Diff Verify Record COMPARING SCREENSHOTS SCREENSHOT TESTING 

WHY DO THIS? SCREENSHOT TESTING • They assert more properties than a unit test normally does 

SCREENSHOT TESTING EVERYTHING THE LIGHT TOUCHES IS OUR… TEST! 

WHY DO THIS? SCREENSHOT TESTING • They assert more properties than a unit test normally does • A fast way to see how our view looks while developing • Immediately detect UI breaking changes and avoid regression bugs 

MULTIPLE UI CASES SCREENSHOT TESTING 

TESTING LANGUAGES SCREENSHOT TESTING 

TESTING DEVICES SIZES SCREENSHOT TESTING 

TESTING THEMES SCREENSHOT TESTING 

SCREENSHOT TESTING 

SCREENSHOT TESTING 

+ KARUMI/SHOT GRADLE PLUGIN SCREENSHOT-TESTS-FOR-ANDROID • Developed and used by Facebook • Html report (visual diff of failed tests) • CI friendly 

FIRST TEST import org.junit.Test class MyFirstTest { @Test @Throws(Throwable::class) fun testRendering() { } } 

FIRST TEST import org.junit.Test class MyFirstTest { @Test @Throws(Throwable::class) fun testRendering() { val targetContext = getInstrumentation().targetContext val inflater = LayoutInflater.from(targetContext) val view = inflater.inflate(R.layout.market_hours_view, null, false) } } 

FIRST TEST import org.junit.Test class MyFirstTest { @Test @Throws(Throwable::class) fun testRendering() { val targetContext = getInstrumentation().targetContext val inflater = LayoutInflater.from(targetContext) val view = inflater.inflate(R.layout.market_hours_view, null, false) ViewHelpers.setupView(view).setExactWidthDp(300).layout() } } 

FIRST TEST import org.junit.Test class MyFirstTest { @Test @Throws(Throwable::class) fun testRendering() { val targetContext = getInstrumentation().targetContext val inflater = LayoutInflater.from(targetContext) val view = inflater.inflate(R.layout.market_hours_view, null, false) ViewHelpers.setupView(view).setExactWidthDp(300).layout() } } 

FIRST TEST import org.junit.Test class MyFirstTest { @Test @Throws(Throwable::class) fun testRendering() { val targetContext = getInstrumentation().targetContext val inflater = LayoutInflater.from(targetContext) val view = inflater.inflate(R.layout.market_hours_view, null, false) ViewHelpers.setupView(view).setExactWidthDp(300).layout() } } 

FIRST TEST import org.junit.Test class MyFirstTest { @Test @Throws(Throwable::class) fun testRendering() { val targetContext = getInstrumentation().targetContext val inflater = LayoutInflater.from(targetContext) val view = inflater.inflate(R.layout.market_hours_view, null, false) ViewHelpers.setupView(view).setExactWidthDp(300).layout() Screenshot.snap(view).record() } } 

DEMO 

THE PERFECT PULL REQUEST 

MEDIUM BLOG POST https://medium.com/xmglobal 

REFERENCES • https://speakerdeck.com/linakis/screenshot-testing-for-android • https://medium.com/xmtrading/screenshot-testing-101-7dd24ca6b8ce • https://github.com/trading-point/screenshot-testing-android-demo • https://youtu.be/tpHsAx8HSkU • https://facebook.github.io/screenshot-tests-for-android/ • https://github.com/Karumi/Shot 

THANK YOU QUESTIONS?