Combining Testing with Formal Specifications: A Case Study

This paper describes our experience specifying, implementing, and validating a record-oriented text editor similar to one discussed in [7]. Algebraic axioms served as the specification notation; and the implementation was tested with a compiler-based system that uses the axioms to test implementations with a finite collection of test cases. Formal specifications were sometimes difficult to produce, but helped reveal errors during unit testing. Thorough exercising of the implementations by the specifications resulted in few errors persisting until integration.