From 49a151628caf335a9776c4579aac26c4042b2c5f Mon Sep 17 00:00:00 2001
From: guybedford <guybedford@gmail.com>
Date: Wed, 3 Feb 2016 21:32:29 +0200
Subject: [PATCH] ensure optional dependencies parsing

---
 lib/npm.js | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/npm.js b/lib/npm.js
index fa2f089..9a3a7fb 100644
--- a/lib/npm.js
+++ b/lib/npm.js
@@ -248,19 +248,23 @@ NPMLocation.prototype = {
 
     packageConfig.dependencies = parseDependencies(packageConfig.dependencies, this.ui);
     packageConfig.peerDependencies = parseDependencies(packageConfig.peerDependencies, this.ui);
+    packageConfig.optionalDependencies = parseDependencies(packageConfig.optionalDependencies, this.ui);
 
-    // by default we install optionalDependencies as peerDependencies
-    // when supported in jspm via https://github.com/jspm/jspm-cli/issues/1441, 
-    // optionalDependencies will be optional peer dependencies
-    if (packageConfig.optionalDependencies) {
+    // ensure optionalDependencies take preference over peer and normal dependencies
+    if (packageConfig.optionalDependencies)
       Object.keys(packageConfig.optionalDependencies).forEach(function(dep) {
-        if (!packageConfig.peerDependencies[dep]) {
+        if (packageConfig.peerDependencies && packageConfig.peerDependencies[dep])
+          delete packageConfig.peerDependencies[dep];
+        if (packageConfig.dependencies && packageConfig.dependencies[dep])
+          delete packageConfig.dependencies[dep];
+      });
+
+    // ensure peerDependencies take preference over normal dependencies
+    if (packageConfig.peerDependencies)
+      Object.keys(packageConfig.peerDependencies).forEach(function(dep) {
+        if (packageConfig.dependencies[dep])
           delete packageConfig.dependencies[dep];
-          packageConfig.peerDependencies[dep] = packageConfig.optionalDependencies[dep];
-        }
       });
-      packageConfig.optionalDependencies = parseDependencies(packageConfig.optionalDependencies, this.ui);
-    }
 
     if (packageConfig.main instanceof Array)
       this.ui.log('warn', 'Package `' + packageName + '` has a main array, which is not supported.');