Table-Driven Property Checking

Property-based tests

There are two main categories of property-based tests:

• Table-driven

• Generator-driven

We’ve already spent a lot of time on generator-driven tests, in which the input is automatically generated (and possibly filtered) to ensure maximum edge cases are covered. Table-driven tests are a kind of middle ground between generator-driven and example-based tests. As we’ll see in this lesson, they still let us formulate properties over our code, but they also let us choose the actual input using a testing table.

Testing tables are just tables with as many columns as inputs for the unit under test. For example, if we’re testing a stand-alone pure function, we’d have as many columns as the number of parameters of the function itself and as many rows as the number of scenarios we want to test.