buddy check-deps

buddy check-deps reports every package the project’s Jest config uses, through its whole preset chain, that no dependency field of package.json declares.

Usage

buddy check-deps [--cwd <dir>]

Alias: buddy check-dependencies.

Options

Option	Type	Default	Effect
--cwd	string	the current directory	The project to check. It must hold a package.json.

The global options also apply.

How it works

1. It finds the Jest config. It tries jest.config.js, jest.config.mjs, jest.config.cjs, jest.config.ts, jest.config.mts, jest.config.cts, and jest.config.json, in that order. When none exists, it uses the jest key of package.json. A module config may export an object or a function, sync or async.
2. It lists the packages that config names, with the field that names each one (transform, watchPlugins, preset, and so on).
3. It follows preset. It resolves the preset from the project directory as the module itself, then as <preset>/jest-preset.js, then as <preset>/jest-preset.json. It repeats for that preset’s own preset, up to 10 levels, and stops on a loop.
4. It compares the list with dependencies, devDependencies, peerDependencies, and optionalDependencies.

Rules:

• A package found in node_modules but not declared still counts as missing. The next install can remove it.
• jest-environment-node is never reported. It arrives with Jest.
• The project’s own package name is never reported.
• A preset that does not load gives the warning could not load preset "<name>". The preset package itself is then reported as missing.
• The install line follows the packageManager field of package.json, searched in the project directory and then in each parent directory: pnpm add -D, yarn add -D, bun add -d, or npm i -D when none is set.

The packages a preset needs can depend on what is already installed. For example, @repobuddy/jest/presets/ts reported jest-esm-transformer-2 and ts-jest in one project and @swc/jest after those two were declared. Run the command again after you install.

Output

All declared:

dependencies: 3 used by jest.config.mjs, all declared in package.json

No Jest config:

dependencies: no jest configuration found, nothing to check

Missing packages (a project with "packageManager": "pnpm@10.0.0" and only @repobuddy/jest and jest declared):

missing dependencies: 5 used by jest.config.mjs but not declared in package.json
  jest-esm-transformer-2    preset(@repobuddy/jest/presets/ts-watch) transform
  jest-watch-suspend        preset(@repobuddy/jest/presets/ts-watch) watchPlugins
  jest-watch-toggle-config  preset(@repobuddy/jest/presets/ts-watch) watchPlugins
  jest-watch-typeahead      preset(@repobuddy/jest/presets/ts-watch) watchPlugins
  ts-jest                   preset(@repobuddy/jest/presets/ts-watch) transform
install: pnpm add -D jest-esm-transformer-2 jest-watch-suspend jest-watch-toggle-config jest-watch-typeahead ts-jest

Each detail line names the package, then where it came from: the config file or preset(<name>), and the field. When the config lives in package.json, the summary says used by package.json#jest.

Exit codes

Code	When
0	Every package is declared, or the project has no Jest config.
1	At least one package is missing, or the directory has no readable package.json.
2	An unknown option.

Examples

Check the current project

buddy check-deps

Check a workspace package from the repository root

buddy check-deps --cwd packages/app

A preset that does not resolve

jest.config.cjs:

module.exports = { preset: 'no-such-preset' }

could not load preset "no-such-preset"
missing dependencies: 1 used by jest.config.cjs but not declared in package.json
  no-such-preset  jest.config.cjs preset
install: npm i -D no-such-preset

A directory that is not a project

buddy check-deps --cwd does-not-exist

cannot read the project at does-not-exist
check-deps needs a directory with a package.json

Related

• Check Jest dependencies in CI
• @repobuddy/jest: the presets this command follows.