flex and main axis margin

src/Layout.js

@@ -208,7 +208,9 @@ var computeLayout = (function() {
         for (var/*int*/ i = 0; i < node.children.length; ++i) {
           var/*css_node_t**/ child = node.children[i];
           if (getFlex(child)) {
-            child.layout[dim[mainAxis]] = flexibleMainDim;
+            child.layout[dim[mainAxis]] = flexibleMainDim -
+              getMargin(child, leading[mainAxis]) -
+              getMargin(child, trailing[mainAxis]);
             layoutNode(child);
           }
         }

src/__tests__/Layout-test.js

@@ -606,7 +606,18 @@ describe('Layout', function() {
         {width: 0, height: 0, top: 100, left: 0}
       ]}
     );
-  })
+  });
+
+  it('should llll', function() {
+    testLayout(
+      {style: {width: 700, flexDirection: 'row'}, children: [
+        {style: {marginLeft: 5, flex: 1}}
+      ]},
+      {width: 700, height: 0, top: 0, left: 0, children: [
+        {width: 695, height: 0, top: 0, left: 5}
+      ]}
+    );
+  });
 
   it('should layout randomly', function() {
     function RNG(seed) {