jest-cli 30.x

Complete instructions

Verified against jest-cli@30.5.1 on 2026-09-08. 2 of 2 examples executed.

jest-cli 30

Surface

jest-cli exposes exactly three named exports:

buildArgv(maybeArgv?: string[]): Promise<Config.Argv>
run(maybeArgv?: string[], project?: string): Promise<void>
yargsOptions: {[key: string]: Options}

Use the package's documented exports rather than deep imports into Jest internals. Jest 30 bundles internals, so paths such as jest-runner/build/testWorker are not stable.

Parse CLI arguments with buildArgv

buildArgv asynchronously converts an argument array into Jest's parsed argument object. Pass only the arguments that would follow the jest command.

import assert from 'node:assert/strict';
import {buildArgv} from 'jest-cli';

const argv = await buildArgv(['--runInBand']);
assert.equal(argv.runInBand, true);

CLI values take precedence over configuration values when Jest runs. Flags requiring values are validated; for example, --maxWorkers and --selectProjects must be given values.

Run Jest programmatically

run starts the Jest command-line runner and resolves when the run completes:

import {run} from 'jest-cli';

await run(['--runInBand'], process.cwd());

The runner needs an actual Jest project and test-runner environment. It is not demonstrated as a standalone executable example here because the required examples run with no test files, configuration file, framework globals, filesystem setup, or network access. Ordinary jest and npm test usage is the supported runner boundary.

Programmatic users of lower-level APIs such as jest.runCLI must provide the newly required globalConfig in Jest 30. Prefer the documented jest-cli exports instead of relying on internals.

Inspect the option definitions

yargsOptions is the exported map of CLI option definitions. The package declaration does not document a complete list of keys or additional behavior.

import assert from 'node:assert/strict';
import {yargsOptions} from 'jest-cli';

assert.equal(typeof yargsOptions, 'object');
assert.notEqual(yargsOptions, null);

Jest 30 CLI changes

Rename --testPathPattern

Jest 29 code commonly uses:

jest --testPathPattern="unit/.*"

In Jest 30, use the plural option:

jest --testPathPatterns "unit/.*" "integration/.*"

Multiple patterns can be space-separated or supplied repeatedly. --testPathPattern was renamed to --testPathPatterns.

--init was removed

Do not use:

jest --init

Use the package-manager generators instead:

npm init jest@latest
yarn create jest
pnpm create jest

Filter result shape

A custom --filter implementation must return an object with an array property:

{filtered: string[]}

Returning an array directly is the older shape.

Common Jest 29-era mistakes

These changes are outside the three jest-cli exports but affect projects upgraded to Jest 30:

• Replace expect(fn).toBeCalled() with expect(fn).toHaveBeenCalled(); matcher aliases were removed.
• Replace jest.genMockFromModule('fs') with jest.createMockFromModule('fs'); genMockFromModule was removed.
• Ensure jest.mock() module paths use exact case.
• Custom sequencers receive additional context in Jest 30.

Runtime requirements

Jest 30 requires Node 18.x or later. Node 14, 16, 19, and 21 are unsupported. The minimum TypeScript version is 5.4. jest-environment-jsdom uses JSDOM 26.

Not covered

This skill does not document the complete yargsOptions key set, Jest configuration options, test discovery, custom sequencer APIs, the detailed globalConfig shape for lower-level runner APIs, or how to construct a runnable Jest project. Those require behavior or documentation not covered by the supplied research.