Learn how mocking in JavaScript tests works by implementing them from scratch!
In this material, we have a set of no-framework
tests that correspond to a set
of jest tests (in the __tests__
directory). The idea is that (with the
exception of the first test), you look at the jest version first, then see how
that would be implemented without a testing framework.
Order of material:
monkey-patching.js
(no jest version)mock-fn.js
spy.js
inline-module-mock.js
external-mock-module.js
The files are intended to test the thumb-war.js
module and mock the utils
module.
To run the tests, run npx jest
. To start watch mode run npx jest --watch
You can definitely run the no-framework
files just using node
(like this:
node src/no-framework/monkey-patching.js
), but in an effort to make running
these easier, I created a custom jest runner that uses jest to run the files,
but allow them to be run without the jest testing framework. It's really cool.
It uses create-jest-runner
and should probably be published eventually.
npm test src/__tests__/mock-fn.js