to-ava

Codemod to convert tests written in jest to ava.

Check fixtures/ folder to see some example.

Usage

Install

npm i -g to-ava

Run it on a Javascript file

to-ava ./jest.test.js

Run it on a Typescript file

to-ava -p=ts ./jest.test.ts

Run it on a folder

to-ava -p=ts ./tests

Notes

It excludes files that are not test files. A file is supposed to contain tests if its name includes either test. either spec.

Support

Supported Assertions

• [X] .toEqual
• [X] .toBe
• [X] .toBeNull
• [X] .toBeFalsy
• [X] .toBeTruthy
• [X] .toMatchSnapshot
• [X] .toBeDefined
• [X] .toBeUndefined
• [X] .toBeInstanceOf
• [X] .toBeGreaterThan
• [X] .toBeGreaterThanOrEqual
• [X] .toBeLessThan
• [X] .toBeLessThanOrEqual
• [X] .toHaveLength
• [X] .toHaveProperty

Other things supported

• [X] test.each()
• [X] trasnformation of test hooks (before(), beforeEach(), after(), afterAll())

Assertions not supported

All the other assertions are not supported. Including all the assertions used in combination with .not - for example .not.toBeDefined()

Those assertions will be still transformed, however not into an ava assertion, but as a comment with the "TODO: " symbol. Thanks for the "TODO: " symbol, it will be possible to find all the assertions not transformed, and fix them manually.

For example

expect(res).toContain('0')

// will be transformed into

// TODO: expect(res).toContain('0');

Other things not supported

• [ ] nested describe() - require manual rewriting of jest tests in order to remove nested describe()
• [ ] skipped tests describe.skip(), it.skip()

Test

npm t

TODO

• [X] add support for beforeEach, beforeAll, afterEach, afterAll
• [ ] refactor: split the transformer into multiple functions, with clear names
• [ ] add support for more jest assertion. The list follows:
  • [ ] .not.toBeDefined
  • [ ] .not.toBeNull
  • [ ] .not.toContain
  • [ ] .not.toEqual
• [ ] add support for nested describes

Resources

• Ava to Jest transformers
• AST Explorer