Rive Runtime Library and Unit Testing

Oct 13, 2025 by wbrum.org 80 views

Introduction

When creating unit tests for Android applications, especially those that utilize Android Jetpack Compose and Kotlin, developers may encounter the java.lang.UnsatisfiedLinkError exception. This error typically occurs when the Java Virtual Machine (JVM) is unable to find or load a native library required by the application. In this article, we will focus on resolving the java.lang.UnsatisfiedLinkError exception when testing components that utilize the Rive runtime library in Kotlin.

Understanding the Error

The java.lang.UnsatisfiedLinkError exception is thrown when the JVM is unable to find or load a native library required by the application. This error can occur due to various reasons, including:

Missing native library: The native library required by the application is missing or not properly loaded.
Incorrect library version: The version of the native library loaded by the JVM does not match the version required by the application.
Library loading issues: Issues with loading the native library, such as incorrect path or permissions.

Rive Runtime Library and Unit Testing

The Rive runtime library is a powerful tool for creating interactive, animated graphics in Android applications. However, when testing components that utilize the Rive runtime library, developers may encounter the java.lang.UnsatisfiedLinkError exception. This error can occur due to the following reasons:

Missing Rive runtime library: The Rive runtime library is not properly loaded or is missing in the test environment.
Incorrect Rive runtime library version: The version of the Rive runtime library loaded by the JVM does not match the version required by the application.

Resolving the Error

To resolve the java.lang.UnsatisfiedLinkError exception when testing components that utilize the Rive runtime library, follow these steps:

Step 1: Verify the Rive Runtime Library Version

Ensure that the version of the Rive runtime library loaded by the JVM matches the version required by the application. You can verify the version of the Rive runtime library by checking the build.gradle file for the following configuration:

dependencies {
    implementation 'com.rivereffects:rive:1.0.0'
}

Step 2: Add the Rive Runtime Library to the Test Environment

Add the Rive runtime library to the test environment by including the following configuration in the build.gradle file:

android {
    defaultConfig {
        // ...
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    testOptions {
        unitTests {
            includeAndroidResources = true
        }
    }
}

dependencies {
    implementation 'com.rivereffects:rive:1.0.0'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test:runner:1.4.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}

Step 3: Use the `@Test` Annotation with the `@RunWith` Annotation

Use the @Test annotation with the @RunWith annotation to specify the test runner for the unit test. For example:

import org.junit.runner.RunWith
import androidx.test.runner.AndroidJUnit4

@RunWith(AndroidJUnit4::class)
class MyUnitTest {
    @Test
    fun testMyFunction() {
        // Test code here
    }
}

Step 4: Use the `@Before` Annotation to Load the Rive Runtime Library

Use the @Before annotation to load the Rive runtime library before running the unit test. For example:

import org.junit.Before
import org.junit.Test
import androidx.test.runner.AndroidJUnit4

@RunWith(AndroidJUnit4::class)
class MyUnitTest {
    @Before
    fun setup() {
        // Load the Rive runtime library here
        System.loadLibrary("rive")
    }

    @Test
    fun testMyFunction() {
        // Test code here
    }
}

Conclusion

In conclusion, the java.lang.UnsatisfiedLinkError exception can occur when testing components that utilize the Rive runtime library in Kotlin. To resolve this error, ensure that the version of the Rive runtime library loaded by the JVM matches the version required by the application. Add the Rive runtime library to the test environment, use the @Test annotation with the @RunWith annotation, and use the @Before annotation to load the Rive runtime library before running the unit test.

Additional Tips

Use the @RunWith annotation with the AndroidJUnit4 class: This annotation specifies the test runner for the unit test and ensures that the test is run on the Android device or emulator.
Use the @Before annotation to load the Rive runtime library: This annotation loads the Rive runtime library before running the unit test, ensuring that the library is properly loaded and available for use.
Use the System.loadLibrary method to load the Rive runtime library: This method loads the Rive runtime library into the JVM, making it available for use in the unit test.

Example Use Case

Here is an example use case that demonstrates how to use the Rive runtime library in a unit test:

import org.junit.Before
import org.junit.Test
import androidx.test.runner.AndroidJUnit4

@RunWith(AndroidJUnit4::class)
class MyUnitTest {
    @Before
    fun setup() {
        // Load the Rive runtime library here
        System.loadLibrary("rive")
    }

    @Test
    fun testMyFunction() {
        // Create a Rive runtime instance
        val rive = RiveRuntime()

        // Load a Rive file
        val file = FileAssetLoader("heart_Particle.riv")

        // Get the animation
        val animation = rive.getAnimation(file)

        // Play the animation
        animation.play()

        // Test the animation
        // ...
    }
}

Q&A: Resolving the java.lang.UnsatisfiedLinkError Exception in Unit Tests

Q: What is the java.lang.UnsatisfiedLinkError exception?

A: The java.lang.UnsatisfiedLinkError exception is thrown when the Java Virtual Machine (JVM) is unable to find or load a native library required by the application.

Q: Why do I get the java.lang.UnsatisfiedLinkError exception in my unit tests?

A: You may get the java.lang.UnsatisfiedLinkError exception in your unit tests if the Rive runtime library is not properly loaded or is missing in the test environment.

Q: How do I resolve the java.lang.UnsatisfiedLinkError exception in my unit tests?

A: To resolve the java.lang.UnsatisfiedLinkError exception in your unit tests, follow these steps:

Verify the Rive Runtime Library Version: Ensure that the version of the Rive runtime library loaded by the JVM matches the version required by the application.
Add the Rive Runtime Library to the Test Environment: Add the Rive runtime library to the test environment by including the necessary configuration in the build.gradle file.
Use the @Test Annotation with the @RunWith Annotation: Use the @Test annotation with the @RunWith annotation to specify the test runner for the unit test.
Use the @Before Annotation to Load the Rive Runtime Library: Use the @Before annotation to load the Rive runtime library before running the unit test.

Q: What is the difference between the `@Test` and `@Before` annotations?

A: The @Test annotation is used to mark a method as a test method, while the @Before annotation is used to specify a method that should be executed before each test method.

Q: How do I use the `System.loadLibrary` method to load the Rive runtime library?

A: To use the System.loadLibrary method to load the Rive runtime library, follow these steps:

Import the System class: Import the System class to access the loadLibrary method.
Specify the library name: Specify the name of the library to load, which is typically the name of the library without the .so extension.
Call the loadLibrary method: Call the loadLibrary method to load the library into the JVM.

Q: What are some common issues that can cause the java.lang.UnsatisfiedLinkError exception?

A: Some common issues that can cause the java.lang.UnsatisfiedLinkError exception include:

Missing native library: The native library required by the application is missing or not properly loaded.
Incorrect library version: The version of the native library loaded by the JVM does not match the version required by the application.
Library loading issues: Issues with loading the native library, such as incorrect path or permissions.

Q: How do I troubleshoot the java.lang.UnsatisfiedLinkError exception?

A: To troubleshoot the java.lang.UnsatisfiedLinkError exception, follow these steps:

Check the library version: Verify that the version of the native library loaded by the JVM matches the version required by the application.
Check the library path: Verify that the path to the native library is correct and that the library is properly loaded.
Check the library permissions: Verify that the native library has the necessary permissions to be loaded by the JVM.

Q: What are some best practices for resolving the java.lang.UnsatisfiedLinkError exception?

A: Some best practices for resolving the java.lang.UnsatisfiedLinkError exception include:

Verify the library version: Ensure that the version of the native library loaded by the JVM matches the version required by the application.
Use the @Before annotation to load the library: Use the @Before annotation to load the library before running the unit test.
Use the System.loadLibrary method to load the library: Use the System.loadLibrary method to load the library into the JVM.