Implement strokeDasharray correctly.

Support units and percentages with whitespace separated and/or (possibly white-space surrounded) comma separated length lists.

lib/extract/extractStroke.js

@@ -1,8 +1,7 @@
 import extractBrush from './extractBrush';
 import extractOpacity from './extractOpacity';
 import {strokeProps} from '../props';
-
-const separator = /\s*,\s*/;
+import extractLengthList from "./extractLengthList";
 
 const caps = {
     butt: 0,
@@ -26,21 +25,22 @@ export default function(props, styleProperties) {
     });
 
     const {stroke} = props;
-    let strokeWidth = props.strokeWidth;
-    let strokeDasharray = props.strokeDasharray;
+    let {
+        strokeWidth,
+        strokeDasharray
+    } = props;
 
     if (!strokeDasharray || strokeDasharray === 'none') {
         strokeDasharray = null;
-    } else if (typeof strokeDasharray === 'string') {
-        strokeDasharray = strokeDasharray.split(separator).map(dash => +dash);
-    }
-
-    // <dasharray> It's a list of comma and/or white space separated <length>s
-    // and <percentage>s that specify the lengths of alternating dashes and gaps.
-    // If an odd number of values is provided, then the list of values is repeated
-    // to yield an even number of values. Thus, 5,3,2 is equivalent to 5,3,2,5,3,2.
-    if (strokeDasharray && (strokeDasharray.length % 2) === 1) {
-        strokeDasharray.concat(strokeDasharray);
+    } else {
+        // <dasharray> It's a list of comma and/or white space separated <length>s
+        // and <percentage>s that specify the lengths of alternating dashes and gaps.
+        // If an odd number of values is provided, then the list of values is repeated
+        // to yield an even number of values. Thus, 5,3,2 is equivalent to 5,3,2,5,3,2.
+        strokeDasharray = extractLengthList(strokeDasharray);
+        if (strokeDasharray && (strokeDasharray.length % 2) === 1) {
+            strokeDasharray.concat(strokeDasharray);
+        }
     }
 
     if (!strokeWidth || typeof strokeWidth !== 'string') {