I spent my days to solve the problem after update to AndroidStudio 3.3
Error below contionues to appear even i delete everything about android and android studio from my computer and reinstall again.
Could not find method testImplementation() for arguments [junit:junit:4.12] on object of type org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.
Finally, i change testImplementation to testCompile. Then following androidTestImplementation words to androidTestCompile.
But as you may already know if you use the latest version of Android Studio, you will see: Compile term is outdated and the message says “It will be removed at the end of 2018”
We already past 2018 🙂
After i solve my problem with Compile command (nothing to do. testImplementation completely makes my AndroidStudio non working) i continue coding my projects. After i while i remember Java always had problem with Turkish characters.
Then i decided to try what if i wrote testİmplementation. I change the capital I letter with Turkish İ. What I suprise! It works!!!
So, for Turkish Windows (and may be others) the solution is to change the following part of app’s build.gradle
androidTestImplementation 'com.android.support.test:runner:1.0.2'<br> androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
Hope this article helps.