Sometimes you might need to add setup files (json/xml/.properties/etc.) to your instrumentation tests (androidTest) and load them in your tests. You usually do that when loading for example some mocked data set or some fixture.
In testing, fixtures often take the form of JSON or yaml files that mimic the responses from real API calls. These are used to simulate the API behaviour during testing, without the need to make actual API calls. This approach is beneficial for your tests for various reasons:
- Speed: Testing with fixtures is faster since it doesn’t rely on real-time network calls thus making your integration tests more speedy.
- Reliability: Removes dependencies on external systems, which might be down or unreliable during testing.
- Control: Enables you to test how your application handles various edge cases and error conditions by providing predefined responses.
- Cost: Reduces the number of calls to paid APIs, cutting down on costs. (if it is the case…)
One way to do that is to add them to the assets directory of your instrumentation tests setup.
Add(if you don’t have it created yet!) the assets directory to your src/androidTest path and under it you can add your files. It should look like this: src/androidTest/assets/your_file_here
To access the files from your instrumentation tests you can use the context and then resources and assets like this:
InstrumentationRegistry.getInstrumentation().context.resources.assets.open("your_file_name")
Of course you have to replace “your_file_name” with the name of the file you want to load in your tests or test.
If needed, you can also use this approach to debug the implementation in your instrumentation test.
