fix "Enable using a custom npm registry" issue (#123)

fix "Enable using a custom npm registry" issue

src/npm-utils.js

@@ -137,7 +137,70 @@ function oldNpmCache(pkg, deferred) {
  * @return {Promise<Object>} The manifest object.
  */
 function getManifest(pkg) {
-  return require('pacote').manifest(pkg).then((pkgJson) => ({
+  // detect custom registry and user auth info
+  let opts = {
+    registry: npm.config.get('registry'),
+  };
+
+  // https://github.com/npm/npm/blob/latest/lib/config/pacote.js
+  npm.config.keys.forEach(function(k) {
+    const authMatchGlobal = k.match(
+      /^(_authToken|username|_password|password|email|always-auth|_auth)$/
+    );
+    const authMatchScoped = k[0] === '/' && k.match(
+      /(.*):(_authToken|username|_password|password|email|always-auth|_auth)$/
+    );
+
+    // if it matches scoped it will also match global
+    if (authMatchGlobal || authMatchScoped) {
+      let nerfDart = null;
+      let key = null;
+      let val = null;
+
+      if (!opts.auth) {
+       opts.auth = {};
+      }
+
+      if (authMatchScoped) {
+        nerfDart = authMatchScoped[1];
+        key = authMatchScoped[2];
+        val = npm.config.get(k);
+        if (!opts.auth[nerfDart]) {
+          opts.auth[nerfDart] = {
+            alwaysAuth: !!npm.config.get('always-auth'),
+          };
+        }
+      } else {
+        key = authMatchGlobal[1];
+        val = npm.config.get(k);
+        opts.auth.alwaysAuth = !!npm.config.get('always-auth');
+      }
+
+      const auth = authMatchScoped ? opts.auth[nerfDart] : opts.auth;
+      if (key === '_authToken') {
+        auth.token = val;
+      } else if (key.match(/password$/i)) {
+        auth.password =
+          // the config file stores password auth already-encoded. pacote expects
+          // the actual username/password pair.
+          Buffer.from(val, 'base64').toString('utf8');
+      } else if (key === 'always-auth') {
+        auth.alwaysAuth = val === 'false' ? false : !!val;
+      } else {
+        auth[key] = val;
+      }
+    }
+
+    if (k[0] === '@') {
+      if (!opts.scopeTargets) {
+       opts.scopeTargets = {};
+      }
+      opts.scopeTargets[k.replace(/:registry$/, '')] = npm.config.get(k);
+    }
+  });
+
+
+  return require('pacote').manifest(pkg, opts).then((pkgJson) => ({
     integrity: pkgJson._integrity,
     manifest: {
       name: pkgJson.name,