From e5132e3f792de889af1f59aef38b05a7d2a2d41e Mon Sep 17 00:00:00 2001
From: guybedford <guybedford@gmail.com>
Date: Thu, 15 Sep 2016 17:37:43 +0200
Subject: [PATCH] allow conditions to directly imply interpolation variations

---
 lib/trace.js | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/lib/trace.js b/lib/trace.js
index a6c8665..233d4a2 100644
--- a/lib/trace.js
+++ b/lib/trace.js
@@ -330,6 +330,24 @@ Trace.prototype.getLoadRecord = function(canonical, traceOpts, parentStack) {
       if (condition.indexOf('|') == -1)
         condition += '|default';
 
+      // if the condition values have been provided via traceOpts.conditions
+      // then we dont need to work out variations from the file system and can just take what is given
+      if (traceOpts.conditions[condition]) {
+        var branches = {};
+        traceOpts.conditions[condition].forEach(function(c) {
+          var branchCanonical = canonical.substr(0, interpolationMatch.index) + c + canonical.substr(interpolationMatch[0].length + interpolationMatch.index);
+          branches[c] = branchCanonical;
+        });
+        return {
+          name: canonical,
+          fresh: false,
+          conditional: {
+            condition: condition,
+            branches: branches
+          }
+        };
+      }
+
       var metadata = {};
       return Promise.resolve(loader.locate({ name: normalized.replace(interpolationRegEx, '*'), metadata: metadata }))
       .then(function(address) {