pak

Programmatic wrapper around popular Node.js package managers

Supports:

• npm
• Yarn Classic
• Yarn Berry

(not all features are available for all package managers)

Usage

Auto-detect the correct package-manager to use

import { detectPackageManager } from "pak";

async function main() {
	// Use the current working directory
	const pak = await detectPackageManager();

	// Or use a different directory. The package manager will default to that dir
	const pak = await detectPackageManager({ cwd: "/path/to/dir" });
}

detectPackageManager takes an options object with the following properties:

{
	/** The working directory for the package manager. Detection will start from here upwards. */
	cwd?: string;
	/** Whether to change the `cwd` to operate in the package's root directory instead of the current one. */
	setCwdToPackageRoot?: boolean;
	/** If this is `false` and no package manager with a matching lockfile was found, another pass is done without requiring one */
	requireLockfile?: boolean;
}

Create an instance of a specific package manager

import { packageManagers } from "pak";
const pak = new packageManagers.npm();

Package manager properties

All package managers share the following properties:

Property	Type	Description
cwd	string	The directory to run the package manager commands in. Defaults to process.cwd()
loglevel	"info" | "verbose" | "warn" | "error" | "silent"	Which loglevel to pass to the package manager. Note: Not every package manager supports every loglevel.
stdout	WritableStream	A stream to pipe the command's stdout into.
stderr	WritableStream	A stream to pipe the command's stderr into.
stdall	WritableStream	A stream to pipe the command's stdout and stderr into in the order the output comes.
environment	`"production"	"development"`

Install one or more packages

const result = await pak.install(packages, options);

• packages is an array of package specifiers, like ["pak", "fs-extra"] or ["semver@1.2.3"]
• options: See common options for details.

If packages is empty or undefined, this will install the packages that are defined in package.json in the cwd.

Uninstall one or more packages

const result = await pak.uninstall(packages, options);

• packages is an array of package specifiers, like ["pak", "fs-extra"] or ["semver@1.2.3"]
• options: See common options for details.

Update one or more packages

const result = await pak.update(packages, options);

• packages is an array of package names, like ["pak", "fs-extra"]. If no packages are given, all packages in the current workspace are updated.
• options: See common options for details.

Recompile native packages

const result = await pak.rebuild(packages, options);

• packages is an array of package names, like ["pak", "fs-extra"]. If no packages are given, all packages in the current workspace are rebuilt.
• options: See common options for details.

Pin transitive dependencies to a fixed version

const result = await pak.overrideDependencies(overrides);

• overrides is an object of packages and exact versions, like {"pak": "1.2.3"}

Sometimes it is necessary to update transitive dependencies, meaning dependencies of dependencies. This command changes all occurences of the given overridden dependencies in the current node_modules tree so that the packages have the specified versions. How it works depends on the package manager:

• yarn uses the built-in "resolutions" property for package.json
• npm patches the root package-lock.json and package.json for all dependents of the overridden packages

Note: This command does not support version ranges and it does not check whether the overrides are compatible with the version specified in package.json.

Result object

The returned value is an object with the following properties:

interface CommandResult {
	/** Whether the command execution was successful */
	success: boolean;
	/** The exit code of the command execution */
	exitCode: number;
	/** The captured stdout */
	stdout: string;
	/** The captured stderr */
	stderr: string;
}

Common options

These options are used to influence the commands' behavior. All options are optional:

Option	Type	Description	Default	Commands
dependencyType	"prod" | "dev"	Whether to install a production or dev dependency.	"prod"	all
global	boolean	Whether to install the package globally.	false	all
exact	boolean	Whether exact versions should be used instead of "^ver.si.on".	false	install
ignoreScripts	boolean	Prevent execution of pre/post/install scripts.	false	install
force	boolean	Pass the --force flag to the package manager where applicable. The specific behavior depends on the package manager.	false	install
additionalArgs	string[]	Additional command line args to pass to the underlying package manager.	none	install, uninstall

Find the nearest parent directory with a package.json

await pak.findRoot();
await pak.findRoot("lockfile.json");

Returns a string with a path to the nearest parent directory (including cwd) that contains a package.json (and a lockfile if one was specified). Throws if none was found.

Stream the command output

You can stream the command output (stdout, stderr or both) during the command execution, as opposed to getting the entire output at the end. To do so, set the stdout, stderr and/or stdall properties of the package manager instance to a writable stream. Example:

import { PassThrough } from "stream";
import { packageManagers } from "../../src/index";

const pak = new packageManagers.npm(); // or the automatically detected one
pak.stdall = new PassThrough().on("data", (data) => {
	// For example, log to console - or do something else with the data
	console.log(data.toString("utf8"));
});

// execute commands

Get the version of the package manager

const version = await pak.version();

Returns a string with the package manager's version.

Get the paths of all workspaces in the current monorepo

const workspaces = await pak.workspaces();

Returns an array of strings including the paths of all workspaces in the current monorepo. This will return an empty array if the current directory is not part of a monorepo. A folder will be considered a workspace if it contains a file package.json and it is referenced in the workspaces property of the root package.json.

Pack a project or monorepo package into an installable tarball

const result = await pak.pack(options);

options are optional and control what gets packed where and has the following shape:

interface PackOptions {
	/**
	 * In monorepos, this determines which workspace to pack. Defaults to the current working directory.
	 * This must be a path relative to the repo root.
	 */
	workspace?: string;
	/** Where to save the packed tarball. Defaults to the current working directory */
	targetDir?: string;
}

result is a CommandResult (see above) where the stdout contains the absolute path of the packed tarball.