Testing with Specifications

TODO::work in progress, sorry

During development

Create specifications for data and functions

Selectively instrument function definitions to check function call arguments against the function specification.

• clojure.spec.test.alpha/instrument - check fdef :args

Unit and integration testing

Add specification checks along with unit testing and integration testing to provide a very wide range of data values to be tested (with a minimal amount of code).

• clojure.spec.test.alpha/check - use :args to generate tests to check fdef :ret and :fn

run a suite of spec-generative tests on an entire ns with check. Just one namespace per check expression?

control the number of values check creates for each check expression. As the default is 1000 the checks can take a noticeable time to run (see practicalli/spec-generative-testing)

Many built-in generators for clojure.core data predicates

composite specifications can build generators upon predicate generators.

Pass generator-returning functions to spec, supplying generators for things spec does not know about. Pass an override map to gen in order to supply alternative generators for one or more sub-paths of a spec.

Define your own generators

At run time

Use specifications for run time checking, typically using conform and valid? functions.

Specification are typically the minimal checks required for the system, compared to more extensive checks during test and system integration.

Create lightweight private specifications for tests that run in the production environment.