TypeScript-friendly utils for Sinon testing
This is a simple library to help create stubs with Sinon when working with TypeScript in order to leverage Sinon stubs and the type system more completely together as one without resorting to ugly, untyped hacks like casting stubbed functions to
any or using associative array accesses, neither of which provide IDE-autocompletion of stub properties and methods, nor work well with stricter
tslint rules applied to test sources.
The API consists of the following functions:
Used to provide a fully stubbed interface backed by an optional set of member properties which may form a subset of the overall interface. Function properties will be typed as proper
SinonStubs along with any other specific type information provided by the interface.
Returns a fully stubbed proxy similar to those provided by
stubInterface, but backed first by the optionally given members, and finally by a given object. This is useful for stubbing some properties of an existing object while providing test-specific returns for fakes for others.
stubObject but works with callable TypeScript function types (i.e., functions with properties).
stubObject with objects created from classes with non-public members, the resulting
StubbedType<T> often needs to be passed to a function or constructor that expects a
T, but TypeScript's mapped types (which are the basis of
StubbedType) do not capture non-public class members. Since the
StubbedType returned from
stubObject is backed by a real instance of type
T, it can be simply reverted to type
T by using
fromStub(instance). The implementation of this simply applies a type assertion, but using
fromStub is preferred for clarity, especially given that this library exists to reduce the necessity of using type assertions in tests in the first place.