android difference between testImplementation and androidTestImplementation in build.gradle

Question

I am using andorid studio 3.2 and I am new to testing. I want to add a testing library but I am not getting what should i write in the dependencies section testImplentat

Answer 1

implementation—The dependency is available in all source sets, including the test source sets.

testImplementation—The dependency is only available in the test source set.

androidTestImplementation—The dependency is only available in the androidTest source set.

Android source sets are :

main: Contains your app code. This code is shared amongst all different versions of the app you can build (known as build variants)

androidTest: Contains tests known as instrumented tests.

test: Contains tests known as local tests.