android - Duplicate class org.hamcrest.BaseDescription found in modules jetified-hamcrest-core-1.3.jar

Question

Android studio 3.6

app/build.gradle:

 androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'com.azimolabs.conditionwatcher:conditionwatcher:0.2'
    // Espresso framework
    androidTestImplementation "androidx.test.espresso:espresso-core:$espresso_version"
    androidTestImplementation "androidx.test.espresso:espresso-intents:$espresso_version"
    androidTestImplementation "androidx.test.espresso:espresso-contrib:$espresso_version"
    androidTestImplementation 'org.hamcrest:hamcrest-junit:2.0.0.0'

    // UI Automator framework
    androidTestImplementation 'androidx.test.uiautomator:uiautomator:2.2.0'
    androidTestImplementation 'com.squareup.okhttp3:mockwebserver:3.8.0'

    // for test fragments
    debugImplementation 'androidx.fragment:fragment-testing:1.2.0-rc02'

    testImplementation 'junit:junit:4.12'
    testImplementation 'com.nhaarman:mockito-kotlin-kt1.1:1.5.0'

in gradle.properties:

android.useAndroidX=true
android.enableJetifier=true

Here my Espresso instrumentation test:

import okhttp3.mockwebserver.MockWebServer
import org.junit.After
import org.junit.Before
import org.junit.Rule
import org.junit.Test
import org.hamcrest.text.MatchesPattern
import org.junit.runner.RunWith

@RunWith(AndroidJUnit4::class)
class FeedbackActivityTransportTest {
 @Test
    fun buttonSend_click_checkRequest() {
        val request = mockServer.takeRequest();
        assertEquals("POST", request.method)
        assertThat(
            request.body.toString(),
            MatchesPattern.matchesPattern("("feedback.*"type":2"))")
        )
    }

But I get error:

Duplicate class org.hamcrest.BaseDescription found in modules jetified-hamcrest-core-1.3.jar (org.hamcrest:hamcrest-core:1.3) and jetified-java-hamcrest-2.0.0.0.jar (org.hamcrest:java-hamcrest:2.0.0.0)
Duplicate class org.hamcrest.BaseMatcher found in modules jetified-hamcrest-core-1.3.jar (org.hamcrest:hamcrest-core:1.3) and jetified-java-hamcrest-2.0.0.0.jar (org.hamcrest:java-hamcrest:2.0.0.0)
Duplicate class org.hamcrest.Condition found in modules jetified-hamcrest-core-1.3.jar (org.hamcrest:hamcrest-core:1.3) and jetified-java-hamcrest-2.0.0.0.jar (org.hamcrest:java-hamcrest:2.0.0.0)
Duplicate class org.hamcrest.Condition$1 found in modules jetified-hamcrest-core-1.3.jar (org.hamcrest:hamcrest-core:1.3) and jetified-java-hamcrest-2.0.0.0.jar (org.hamcrest:java-hamcrest:2.0.0.0)

Answer 1

I think this problem happened when you add a dependency (as your situation Hamcrest and another dependency, library, Jar files, etc... is using Hamcrest too! but with another version.

If you force your Hamcrest dependency in app Gradle like below might solve your problem:

configurations.all {
    resolutionStrategy {
        force 'org.hamcrest:hamcrest-junit:2.0.0.0'
    }
}

After apply if you get the same error try to exclude like this:

configurations { compile.exclude group: "junit", module: "junit" }