jest-codemods

library0.35.0jsnpmunverified

jest-codemods is a utility package providing a collection of automated code transformations (codemods) designed to simplify the migration of existing JavaScript and TypeScript test files to the Jest testing framework. It supports migrations from a wide array of popular testing libraries, including AVA, Chai, Expect.js, Jasmine, Mocha, proxyquire, Should.js, Tape, Sinon, and Node-Tap. Currently at version 0.35.0, the project maintains an active release cadence, frequently incorporating new features, bug fixes, and dependency updates. Its primary differentiator is the comprehensive support for various source frameworks, offering both an interactive command-line interface (CLI) for ease of use and direct integration with jscodeshift for more granular control over transformations, making it an indispensable tool for projects transitioning to Jest by significantly reducing manual refactoring efforts.

testing

npm install jest-codemods

github ↗package ↗

INSTALL

IMPORT

SIG · JEST-CODEMODS

jest-codemods

testingjavascriptv0.35.0

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

jest-codemods CLI

✓ npx jest-codemods [path] [options]

This is the recommended and most common way to run jest-codemods, offering an interactive CLI experience to select desired transformations.

Specific Transformer (e.g., AVA)

✓ jscodeshift -t node_modules/jest-codemods/dist/transformers/ava.js <files...>

✗ import { ava } from 'jest-codemods'

For direct, non-interactive use of a specific codemod, install `jscodeshift` globally and point it to the transformer file within the `jest-codemods` package. Do not attempt to import transformers as modules in user code.

Jest Globals Import Transformer

✓ jscodeshift -t node_modules/jest-codemods/dist/transformers/jest-globals-import.js <files...>

✗ import { addJestGlobals } from 'jest-codemods'

This transformer helps add explicit `@jest/globals` imports for Jest's global APIs, useful for projects moving away from implicit globals. It's run via `jscodeshift` directly, similar to other specific transformers.

This demonstrates how to perform a dry run first to preview changes, and then execute the interactive codemods across your project's test files.

npx jest-codemods my-project-root-folder --dry npx jest-codemods my-project-root-folder

jest-codemods --version

Debug

Known issues

gotchaCodemods are powerful but not foolproof. Always review the changes made by `jest-codemods` after execution, especially for complex transformations or edge cases, as manual tweaks may be required.

fix

Run with `--dry` option first to preview changes. Always commit your code before running codemods and review diffs carefully after.

affects: >=0.1.0

breakingUsing the `--force` option bypasses Git safety checks, which can lead to unrecoverable data loss if your working tree is not clean or changes are not backed up. Exercise extreme caution.

fix

Ensure your changes are committed or stashed before running `jest-codemods` without `--dry`, or only use `--force` if you have a reliable backup strategy in place.

affects: >=0.1.0

gotchaEarlier versions (pre-0.32.0) did not include the `jest-globals-import` transformer, which automatically adds explicit `@jest/globals` imports. If migrating older code, ensure you run this specific transformer or handle global imports manually if needed.

fix

After other migrations, run `jscodeshift -t node_modules/jest-codemods/dist/transformers/jest-globals-import.js <files...>` to add explicit global imports. Ensure you are on `jest-codemods` version `0.32.0` or higher to use this transformer.

affects: <0.32.0

gotchaThe package requires Node.js version 12 or higher. Running with older Node.js versions may lead to unexpected errors or installation failures.

fix

Ensure your Node.js environment is updated to version 12 or newer before installing and running `jest-codemods`.

affects: <=0.35.0

Errors

Common errors & fixes

command not found: jest-codemods

`npx` is not installed or the `jest-codemods` package is not found in your `node_modules`.

fix

Ensure `npx` is available (comes with npm 5.2+). If not, install `jest-codemods` globally: `npm install -g jest-codemods` or locally within your project.

Error: This transform is only safe to run on a clean Git working tree. You can override this safety check with --force.

jest-codemods detects uncommitted changes in your Git repository, preventing accidental data loss.

fix

Commit or stash your current changes before running the codemod. If you understand the risks and want to proceed, use the `--force` option: `npx jest-codemods <path> --force`.

SyntaxError: Unknown word (or similar jscodeshift parsing errors)

jscodeshift (the underlying transformation engine) might not be able to parse your source code due to unsupported syntax features (e.g., very new JS/TS features not yet supported by its parser) or misconfigured parser options.

fix

Ensure your `jscodeshift` version is up-to-date. If the issue persists, you might need to manually fix the syntax in the problematic files or use a specific `jscodeshift` parser option if available and applicable.

Upgrade

Version history

0.35.0latest on npm

Audit

Dependencies

jscodeshiftrequiredCore dependency for running the codemods, as jest-codemods builds on top of its transformation engine.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/skovhus/jest-codemods ↗

packagehttps://www.npmjs.com/package/jest-codemods ↗