Maël Nison arcanis

High-level design

The link step essentially consist in three steps:

Tree exposition
Tree serialization
Package builds

The first step is when Yarn communicates to the various linkers to let them know which packages in the dependency tree belong to them, and what are their dependencies.

Getting Started With Plug'n'Play

If you use create-react-app, #5136 (released with the 2.0) implements a --use-pnp option that allows you to easily create a new project using PnP! In this case, just use create-react-app --use-pnp together with Yarn 1.12, and you're good to go! 👍

Plug'n'Play is a new initiative from Yarn that aims to remove the need for node_modules. It's already available, and has proved being effective even on large-scale infrastructures. This document describes in a few steps how to quickly get started with it. Spoiler alert: it's quite easy 🙂

First, download a package manager that supports it. Yarn 1.12 already does, so that's what we're going to use! To install it, just follow the instructions on our website: https://yarnpkg.com/en/docs/install

If everything is ok, running yarn --version should give you v1.12.1 or higher. If you don't get this result maybe a

	# The general idea is that maintainers would publish "meta-packages" that would describe
	# where to find the specific implementations for a given set of parameters (defined by a
	# template string). The template string would be resolved based on the known parameter (after
	# checking that the active parameters are compatible with the supported ones), and the package
	# used instead of the original one.
	#
	# One nice thing is that it would degrade nicely on package managers that wouldn't support this
	# spec: they would simply ignore the `variants` field, and thus would use the package itself,
	# with everything it contains - including a potential fallback.
	#

	module.exports = {
	name: `yarn-plugin-license`,
	factory: require => {
	const {BaseCommand} = require(`@yarnpkg/cli`);
	const {Cache, Configuration, Manifest, Project, StreamReport, miscUtils, structUtils} = require(`@yarnpkg/core`);

	class LicenseCommand extends BaseCommand {
	async execute() {
	const configuration = await Configuration.find(this.context.cwd, this.context.plugins);
	const {project, workspace} = await Project.find(configuration, this.context.cwd);

	diff --git a/yarn.lock b/yarn.lock
	index 391dbc4..7204d18 100644
	--- a/yarn.lock
	+++ b/yarn.lock
	"rc-align@npm:^2.4.0, rc-align@npm:^2.4.1":
	version: 2.4.5
	resolution: "rc-align@npm:2.4.5"
	dependencies:
	babel-runtime: "npm:^6.26.0"
	dom-align: "npm:^1.7.0"

	const locator = structUtils.makeLocator(`debug`, `npm:1.0.0`);

	for (const pkg of project.storedPackages) {
	const dependencies = Array.from(pkg.dependencies.values());

	const isDependent = dependencies.some(dependency => {
	const resolution = project.storedResolutions.get(dependency.descriptorHash)!;
	return resolution === locator.locatorHash;
	});

	module.exports = {
	name: `berry-plugin-is-yarn`,
	factory: () => ({
	default: {
	hooks: {
	setupScriptEnvironment(project, env, makePathWrapper) {
	env.IS_YARN = `1`;
	},
	},
	},

	resolveModuleNames: (moduleNames, containingFile) => {
	try {
	const pnpModuleNames = moduleNames.map(moduleName => {
	const [, prefix, rest] = moduleName.match(/^((?:!.!)?)(.)/);
	const unqualified = require('pnpapi').resolveToUnqualified(rest, containingFile);
	return unqualified !== null ? prefix + unqualified : moduleName;
	});
	const tsResolutions = resolveModuleNames(resolveSync, moduleResolutionHost, appendTsSuffixTo, appendTsxSuffixTo, scriptRegex, instance, pnpModuleNames, containingFile, getResolutionStrategy);

	for (let t = 0; t < tsResolutions.length; ++t)

	class EfficientPrinter {

	constructor() {

	this.lines = null;

	}

	render(text) {

	let refCount = 0;
	let resolvers = [];

	function resolveAll() {

	for (let resolve of resolvers)
	resolve();

	resolvers = [];