Download yarn from custom npm registry

sources/Engine.ts

@@ -199,7 +199,6 @@ export class Engine {
     const packageManagerInfo = await corepackUtils.installVersion(folderUtils.getInstallFolder(), locator, {
       spec,
     });
-    spec.bin ??= packageManagerInfo.bin;
 
     return {
       ...packageManagerInfo,

sources/corepackUtils.ts

@@ -1,20 +1,20 @@
-import {createHash}                                            from 'crypto';
-import {once}                                                  from 'events';
-import {FileHandle}                                            from 'fs/promises';
-import fs                                                      from 'fs';
-import type {Dir}                                              from 'fs';
-import Module                                                  from 'module';
-import path                                                    from 'path';
-import semver                                                  from 'semver';
-
-import * as engine                                             from './Engine';
-import * as debugUtils                                         from './debugUtils';
-import * as folderUtils                                        from './folderUtils';
-import * as fsUtils                                            from './fsUtils';
-import * as httpUtils                                          from './httpUtils';
-import * as nodeUtils                                          from './nodeUtils';
-import * as npmRegistryUtils                                   from './npmRegistryUtils';
-import {RegistrySpec, Descriptor, Locator, PackageManagerSpec} from './types';
+import {createHash}                                                                           from 'crypto';
+import {once}                                                                                 from 'events';
+import {FileHandle}                                                                           from 'fs/promises';
+import fs                                                                                     from 'fs';
+import type {Dir}                                                                             from 'fs';
+import Module                                                                                 from 'module';
+import path                                                                                   from 'path';
+import semver                                                                                 from 'semver';
+
+import * as engine                                                                            from './Engine';
+import * as debugUtils                                                                        from './debugUtils';
+import * as folderUtils                                                                       from './folderUtils';
+import * as fsUtils                                                                           from './fsUtils';
+import * as httpUtils                                                                         from './httpUtils';
+import * as nodeUtils                                                                         from './nodeUtils';
+import * as npmRegistryUtils                                                                  from './npmRegistryUtils';
+import {RegistrySpec, Descriptor, Locator, PackageManagerSpec, BinList, BinSpec, InstallSpec} from './types';
 
 export function getRegistryFromPackageManagerSpec(spec: PackageManagerSpec) {
   return process.env.COREPACK_NPM_REGISTRY
@@ -123,7 +123,15 @@ function parseURLReference(locator: Locator) {
   return {version: encodeURIComponent(href), build: []};
 }
 
-export async function installVersion(installTarget: string, locator: Locator, {spec}: {spec: PackageManagerSpec}) {
+function isValidBinList(x: unknown): x is BinList {
+  return Array.isArray(x) && x.length > 0;
+}
+
+function isValidBinSpec(x: unknown): x is BinSpec {
+  return typeof x === `object` && x !== null && !Array.isArray(x) && Object.keys(x).length > 0;
+}
+
+export async function installVersion(installTarget: string, locator: Locator, {spec}: {spec: PackageManagerSpec}): Promise<InstallSpec> {
   const locatorIsASupportedPackageManager = isSupportedPackageManagerLocator(locator);
   const locatorReference = locatorIsASupportedPackageManager ? semver.parse(locator.reference)! : parseURLReference(locator);
   const {version, build} = locatorReference;
@@ -151,13 +159,18 @@ export async function installVersion(installTarget: string, locator: Locator, {s
 
   let url: string;
   if (locatorIsASupportedPackageManager) {
-    const defaultNpmRegistryURL = spec.url.replace(`{}`, version);
-    url = process.env.COREPACK_NPM_REGISTRY ?
-      defaultNpmRegistryURL.replace(
-        npmRegistryUtils.DEFAULT_NPM_REGISTRY_URL,
-        () => process.env.COREPACK_NPM_REGISTRY!,
-      ) :
-      defaultNpmRegistryURL;
+    url = spec.url.replace(`{}`, version);
+    if (process.env.COREPACK_NPM_REGISTRY) {
+      const registry = getRegistryFromPackageManagerSpec(spec);
+      if (registry.type === `npm`) {
+        url = await npmRegistryUtils.fetchTarballUrl(registry.package, version);
+      } else {
+        url = url.replace(
+          npmRegistryUtils.DEFAULT_NPM_REGISTRY_URL,
+          () => process.env.COREPACK_NPM_REGISTRY!,
+        );
+      }
+    }
   } else {
     url = decodeURIComponent(version);
   }
@@ -190,13 +203,34 @@ export async function installVersion(installTarget: string, locator: Locator, {s
   const hash = stream.pipe(createHash(algo));
   await once(sendTo, `finish`);
 
-  let bin;
-  if (!locatorIsASupportedPackageManager) {
-    if (ext === `.tgz`) {
-      bin = require(path.join(tmpFolder, `package.json`)).bin;
-    } else if (ext === `.js`) {
+  let bin: BinSpec | BinList;
+  const isSingleFile = outputFile !== null;
+
+  // In config, yarn berry is expected to be downloaded as a single file,
+  // and therefore `spec.bin` is an array. However, when dowloaded from
+  // custom npm registry as tarball, `bin` should be a map.
+  // In this case, we ignore the configured `spec.bin`.
+
+  if (isSingleFile) {
+    if (locatorIsASupportedPackageManager && isValidBinList(spec.bin)) {
+      bin = spec.bin;
+    } else {
       bin = [locator.name];
     }
+  } else {
+    if (locatorIsASupportedPackageManager && isValidBinSpec(spec.bin)) {
+      bin = spec.bin;
+    } else {
+      const {name: packageName, bin: packageBin} = require(path.join(tmpFolder, `package.json`));
+      if (typeof packageBin === `string`) {
+        // When `bin` is a string, the name of the executable is the name of the package.
+        bin = {[packageName]: packageBin};
+      } else if (isValidBinSpec(packageBin)) {
+        bin = packageBin;
+      } else {
+        throw new Error(`Unable to locate bin in package.json`);
+      }
+    }
   }
 
   const actualHash = hash.digest(`hex`);
@@ -263,18 +297,19 @@ export async function installVersion(installTarget: string, locator: Locator, {s
 /**
  * Loads the binary, taking control of the current process.
  */
-export async function runVersion(locator: Locator, installSpec: { location: string, spec: PackageManagerSpec }, binName: string, args: Array<string>): Promise<void> {
+export async function runVersion(locator: Locator, installSpec: InstallSpec & {spec: PackageManagerSpec}, binName: string, args: Array<string>): Promise<void> {
   let binPath: string | null = null;
-  if (Array.isArray(installSpec.spec.bin)) {
-    if (installSpec.spec.bin.some(bin => bin === binName)) {
+  const bin = installSpec.bin ?? installSpec.spec.bin;
+  if (Array.isArray(bin)) {
+    if (bin.some(name => name === binName)) {
       const parsedUrl = new URL(installSpec.spec.url);
       const ext = path.posix.extname(parsedUrl.pathname);
       if (ext === `.js`) {
         binPath = path.join(installSpec.location, path.posix.basename(parsedUrl.pathname));
       }
     }
   } else {
-    for (const [name, dest] of Object.entries(installSpec.spec.bin)) {
+    for (const [name, dest] of Object.entries(bin)) {
       if (name === binName) {
         binPath = path.join(installSpec.location, dest);
         break;

sources/npmRegistryUtils.ts

@@ -48,3 +48,16 @@ export async function fetchAvailableVersions(packageName: string) {
   const metadata = await fetchAsJson(packageName);
   return Object.keys(metadata.versions);
 }
+
+export async function fetchTarballUrl(packageName: string, version: string) {
+  const metadata = await fetchAsJson(packageName);
+  const versionMetadata = metadata.versions?.[version];
+  if (versionMetadata === undefined)
+    throw new Error(`${packageName}@${version} does not exist.`);
+
+  const {tarball} = versionMetadata.dist;
+  if (tarball === undefined || !tarball.startsWith(`http`))
+    throw new Error(`${packageName}@${version} does not have a valid tarball.`);
+
+  return tarball;
+}

sources/types.ts

@@ -53,6 +53,12 @@ export interface PackageManagerSpec {
   };
 }
 
+export interface InstallSpec {
+  location: string;
+  bin?: BinList | BinSpec;
+  hash: string;
+}
+
 /**
  * The data structure found in config.json
  */