android test fixtures

Question

I am working on an android app and I have created a new test project for unit tests. Where's recommended to store the test fixtures (like xml files and the like) and what's the proper way to access it ?

Answer 1

It depends if you really mean unit test or instrumented tests (like using espresso and stuff)...

Unit tests:

1. Put your fixtures in src/test/resources (so e.g. src/test/resources/fixture.json)
2. Access them from your test classes e.g. using:

InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("fixture.json")

Instrumented tests:

1. Put your fixtures in src/androidTest/assets/ (so e.g. src/androidTest/assets/fixture.json)
2. Access them from your test classes e.g. using:

InputStream is = InstrumentationRegistry.getContext().getResources().getAssets().open("fixture.json")

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Here are some examples of how you can convert InputStream to String.

Here's a pretty good post describing different cases.

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P.S. I know this question is 6+ years old... answering for any future searches.

Answer 2

After some searching I found there is no one proper way to store fixtures in Android (also not so much in java either).

Fixtures are a way to provide easy and consistent data to be passed into test cases. Creating .java classes with static methods that return objects is one way to go.

Example:

public class Pojos {

    public static List<TaskListItem> taskListItems() {
        return Arrays.asList(
                new TaskListItem("one"),
                new TaskListItem("two"),
                new TaskListItem("three")
        );
    }
}

Answer 3

You can configure Gradle to read resources from a shared folder, you will be able to share code and resources either in unit test or instrumented test by doing the following.

android {
    // ...
    sourceSets {

        final String sharedJavaDir = 'src/sharedTest/java'
        final String sharedResourcesDir = 'src/sharedTest/resources'

        test.java.srcDirs += sharedJavaDir
        test.resources.srcDirs += [sharedResourcesDir]

        androidTest.java.srcDirs += sharedJavaDir
        androidTest.resources.srcDirs += [sharedResourcesDir]

        // ....
    }
    // ...
}

Let's imagine that I setup a shared test resource in

/app/src/sharedTest/resources/test_fixture_file.txt

Kotlin code

In a UnitTest or Instrumented test you can use.

val resource: InputStream? = this.javaClass.getResourceAsStream("/test_fixture_file.txt")