Feedback-Based Specification, Coding and Testing with JWalk

JWalk is a lazy systematic unit-testing tool for Java, which supports dynamic inference of specifications from code and systematic testing from the acquired specification. This paper describes the feedback-based development methodology that is possible using the JWalk Editor, an original Java-sensitive editor and compiler coupled to JWalk, which helps programmers to prototype Java class designs, generating novel test cases as they code. Systematic exploratory testing alerts the programmer to unusual consequences in the design; and confirmed test results become part of the evolving specification, which adapts continuously to modified classes and extends to subclasses. The cycle of coding, inferring and testing systematically exposes test cases that are often missed in other test-driven development approaches, which rely on programmer intuition to create test cases.