Troubleshooting Espresso Tests: Accessing Class Files

Troubleshooting Espresso Tests: Accessing Class Files

11 April 2024 Stephan Petzl Leave a comment Tech-Help

If you’re working with UI testing in Android, particularly with the Espresso framework, you might encounter errors related to class file access. This can be frustrating when your test suite suddenly can’t find classes like AppCompatActivity, IdlingResource, or RecyclerView. Let’s dive into a common issue and its solution to keep your tests running smoothly.

Understanding the Problem

When trying to run UI tests, you may see errors indicating missing class files, such as:

  • AppCompatActivity not found
  • Cannot infer type arguments for ActivityTestRule<>
  • IdlingResource not found
  • RecyclerView not found
  • Compilation failed; see the compiler error output for details

This can occur during the compilation of your AndroidTest Java files, and it’s typically a sign of a dependency issue in your build configuration.

The Solution

The root cause of this problem usually lies within the build.gradle file of your app module. Specifically, it can occur if your Gradle configuration excludes the dependencies required by the instrumentation APK.

Step-by-Step Fix

  1. Open your app module’s build.gradle file.
  2. Locate the block of code that excludes dependencies from the instrumentation APK. It will look something like this:
  3. configurations.implementation.dependencies.all {
        println "Excluding implementation dependency: ${implementationDependency.getName()}"
        configurations.androidTestImplementation.dependencies.all {
            configurations.androidTestImplementation.exclude module: "${implementationDependency.getName()}"
  4. Remove this block of code to ensure that the Android Test implementation can access all necessary dependencies.
  5. Sync your Gradle files with the project by clicking on “Sync Now” in the bar that appears at the top of the build.gradle file editor.
  6. Try running your Espresso tests again.


By ensuring that your test configurations include all the necessary dependencies, your Espresso tests should be able to access all the required class files and run without issue. Remember, it’s important to review and understand the changes you make to your Gradle files to maintain the integrity of both your production and test builds.

Happy testing!

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