SUT
System under test
Direct inputs
The inputs that a SUT directly receives via its interface (i.e method parameters)
Direct outputs
The outputs a SUT directly returns via its interface (i.e method return values)
Indirect inputs
Inputs supplied to the SUT by other components with which it interacts (i.e values supplied by DOCs)
Indirect outputs
Outputs of the SUT that are passed to DOCs but are not visible via the SUT interface
Test double
Generic names for Dummy, Stub, Spy, Fake or Mock
Dummy
Test double that is never used or called but must be present (i.e it could just be null)
Stub
Test double that supplies indirect inputs to SUT (and does nothing else)
Mock
Test double that verifies indirect outputs from SUT (may also provide indirect input)
Spy
Test double that captures indirect outputs from SUT to allow later verification (may also provide indirect input)
Fake
Test double that acts as a lightweight stand in for some other component
Guava
An open source project from Google originally known as Google Collections. It provides common utilities for Java such as collections operations, string processing and caching. See Guava
TDD
Test driven development or Test driven design.