Install dependencies

jko allows you to install dependencies and devDependencies.

$ jko install

It will install dependencies from jko.js or package.json.

info

jko.js takes precedence over package.json.

---

Install dependencies from a File

$ jko install --config-file=./path/to/config.js

or

$ jko install -c=./path/to/config.js

---

Install dependencies from a Package

$ jko install --config-file=somePackageName

or

$ jko install -c=somePackageName

The package must be available, i.e. It must be installed first.

---

Using a Specific Package Manager to Install Dependencies

jko supports the following package managers:

• npm (Default)
• pnpm
• yarn

$ jko install --package-manager=npm

or

$ jko install --p=npm

or by using the jko.js file (package.json or any other file specified with the --config-file option):

export default {
  dependencies: {
    packageName1: "#.#.#",
    packageNameN: "#.#.#"
  },
  devDependencies: {
    devPackageName1: "#.#.#",
    devPackageNameN: "#.#.#"
  },
  packageManager: 'npm',
}

$ jko install

---

How Are Dependencies Installed

1. Before installation begins, $pre (install) is run if it exists.
2. Dependencies are installed as follows:

• Using a non-package.json file (e.g. jko.js): Each dependency is processed independently using the selected package manager command. For example:

  • npm install some0@"4.0.0" && npm install -D some1@"5.0.0" some2@"6.0.0"
  • pnpm add some1@"5.0.0" some2@"6.0.0"

  Additionally, if a package.json file does not exist, it will be created; otherwise, it will be updated.

• Using package.json for installation: All dependencies are processed at once (e.g. by running npm install or yarn install).

3. If everything completes successfully, $post (install) is run if it exists. If an error occurs, $catch (install) is run if defined.

warning

When installing from a non-package.json file, the packageManager doesn't "lock" its version to a fixed package in your lock file. Instead, it treats the package as a new dependency and updates the lock file accordingly.

What happens is:

1. The packageManager determines which version of the package to install based on the semver range (defaulting to the latest version if none is provided).
2. It downloads that version and either adds a new entry or updates the existing one in package.json.
3. It updates or creates package-lock.json with the resolved version.

In this process, the package-lock file isn't "enforcing" a previously locked version for the dependency—It is just updated with the new resolution if any changes occur.

While this approach is often beneficial, it also means you need to manage your semver ranges carefully. For instance, to pin a version, use some@">=1.50.0 && <1.51.0". This guarantees that only version 1.50.x will be installed (with x representing bug fixes), which can be advantageous.

danger

If an install task already exists, jko completely ignores it.

---

Mixing jko.js and JSON

If you want to use jko.js and store dependencies in a JSON file (e.g., package.json), import JSON file into jko.js:

jko.js

import scripts from 'somePackage'
import packageJson from './package.json'  with { type: 'json' }

export default {
  ...packageJson,
  scripts: {
    ...scripts.scripts,
    yourScript1: "someCommand1",
    yourScript2: "someCommand2",
  }
}

This is especially useful when using shared scripts from a local package.