jest-codemods

jest-codemods

Codemods that simplify migrating JavaScript test files to Jest. Currently we support migrating from Tape to Jest. But we plan to support AVA and other test runners in the future.

Codemods are small programs that help you automate changes to your codebase. Think of them as search and replace on steroids. They are executed by the Facebook jscodeshift tool.

This tool is made for trying out Jest on your existing test files. We strive to make the migration as smooth as possible, but some manual intervention and tweaks are to be expected.

Install

$ npm install -g jest-codemods

This installs the runner as jest-codemods.

Usage (CLI)

Currently we support migrating from Tape to Jest.

$ jest-codemods --help

	Codemod that simplify migrating to Jest.

	Usage
	  $ jest-codemods <path> [options]

	path		Files or directory to transform. Can be a glob like src/**.test.js

	Only files with Tape will be converted.

	Options
	  --force, -f	Bypass Git safety checks and forcibly run codemods
	  --dry, -d		Dry run (no changes are made to files)
	  --parser		The parser to use for parsing your source files (babel | babylon | flow)  [babel]

To transform all test files in a directory run jest-codemods mySrcFolder in your terminal.

Only files requiring or importing Tape will be transformed. Notice the console output for errors, manual intervention and tweaks are to be expected.

Usage (jscodeshift)

To make the process as simple as possible, we recommend the jest-codemods CLI that wraps the jscodeshift executable. But you can also run the transformations directly using jscodeshift.

$ npm install -g jscodeshift
$ npm install jest-codemods
$ jscodeshift -t node_modules/jest-codemods/dist/transformers/tape.js mySrcFolder

Inspiration

Thanks to ava-codemods for inspiration.

Contributing

To get started, run:

npm install

When developing:

npm run check  # (runs lint and unit test)
npm run lint
npm run test
npm run test:cov
npm run test:watch

License

MIT