feat: COREPACK_NPM_REGISTRY defaults to the regitry of npm

Author: zanminkian

README.md

@@ -302,7 +302,9 @@ same major line. Should you need to upgrade to a new major, use an explicit
   (useful for commands like `yarn init`).
 
 - `COREPACK_NPM_REGISTRY` sets the registry base url used when retrieving
-  package managers from npm. Default value is `https://registry.npmjs.org`
+  package managers from npm. Default value is the result of command
+  `npm config get registry`, which is typically `https://registry.npmjs.org/`
+  unless it has been customized.
 
 - `COREPACK_NPM_TOKEN` sets a Bearer token authorization header when connecting
   to a npm type registry.

mkshims.ts

@@ -21,6 +21,7 @@ async function main() {
   const corepackPath = path.join(distDir, `corepack.js`);
   fs.writeFileSync(corepackPath, [
     `#!/usr/bin/env node`,
+    `process.env.COREPACK_NPM_REGISTRY??=require('child_process').execSync('npm config get registry', {encoding: 'utf8'}).trim();`,
     `process.env.COREPACK_ENABLE_DOWNLOAD_PROMPT??='0';`,
     `require('module').enableCompileCache?.();`,
     `require('./lib/corepack.cjs').runMain(process.argv.slice(2));`,
@@ -34,6 +35,7 @@ async function main() {
       const entryPath = path.join(distDir, `${binaryName}.js`);
       const entryScript = [
         `#!/usr/bin/env node`,
+        `process.env.COREPACK_NPM_REGISTRY??=require('child_process').execSync('npm config get registry', {encoding: 'utf8'}).trim();`,
         `process.env.COREPACK_ENABLE_DOWNLOAD_PROMPT??='1'`,
         `require('module').enableCompileCache?.();`,
         `require('./lib/corepack.cjs').runMain(['${binaryName}', ...process.argv.slice(2)]);`,