testing - How to read a file from src/instrumentTest/resources directory in Android?

Question

I have an Android application using the new standard gradle layout:

  src/main/java
  src/main/resources
  src/instrumentTest/java
  src/instrumentTest/resources

I have a unit test in src/instrumentTest/java/com/example/MyUnitTest.java that reads a file located in src/instrumentTest/resources/testfile.json

• First question: Is it the right place for placing the testing files?
• Second question: How can I read that file in a String?

I have tried these two ways for reading the file in the unit test with no success (it cannot find the file):

String myJson = new Scanner(new File("testfile.json"),"UTF-8").useDelimiter("\A").next();

String myJson = new Scanner(new File("resources/testfile.json"),"UTF-8").useDelimiter("\A").next();

Cheers!

Answer 1

You can use the assets folder of the build type your are testing. If you are testing the debug type (which is the default one):

src/debug/res/assets

And then you access those files with

InputStream raw = context.getAssets().open("filename.ext");
String myJson = new Scanner(raw).useDelimiter("\A").next();

The trick of using the debug build type prevent your testing resources to be packed in the final apk.