Multiple fake data can be defined by setData(Uri, byte[]) and newData(Uri) methods. It's also possible to define a default data by newDefaultData().

newData(Uri) and newDefaultData() return a FakeDataSet.FakeData instance which can be used to define specific results during FakeDataSource.read(byte[], int, int) calls.

The data that will be read from the source can be constructed by calling FakeDataSet.FakeData.appendReadData(byte[]) Calls to FakeDataSource.read(byte[], int, int) will not span the boundaries between arrays passed to successive calls, and hence the boundaries control the positions at which read requests to the source may only be partially satisfied.

Errors can be inserted by calling FakeDataSet.FakeData.appendReadError(IOException). An inserted error will be thrown from the first call to FakeDataSource.read(byte[], int, int) that attempts to read from the corresponding position, and from all subsequent calls to FakeDataSource.read(byte[], int, int) until the source is closed. If the source is closed and re-opened having encountered an error, that error will not be thrown again.

Actions are inserted by calling FakeDataSet.FakeData.appendReadAction(Runnable). An actions is triggered when the reading reaches action's position. This can be used to make sure the code is in a certain state while testing.

Example usage:

   // Create a FakeDataSource then add default data and two FakeData
   // "test_file" throws an IOException when tried to be read until closed and reopened.
   FakeDataSource fakeDataSource = new FakeDataSource();
   fakeDataSource.getDataSet()
       .newDefaultData()
         .appendReadData(defaultData)
         .endData()
       .setData("http://1", data1)
       .newData("test_file")
         .appendReadError(new IOException())
         .appendReadData(data2)
         .endData();