align hover label to the left for negative radial coords

Author: etpinard

src/traces/barpolar/hover.js

@@ -62,5 +62,9 @@ module.exports = function hoverPoints(pointData, xval, yval) {
     pointData.color = getTraceColor(trace, cdi);
     pointData.xLabelVal = pointData.yLabelVal = undefined;
 
+    if(cdi.s < 0) {
+        pointData.idealAlign = 'left';
+    }
+
     return [pointData];
 };

test/jasmine/tests/barpolar_test.js

@@ -252,7 +252,8 @@ describe('Test barpolar hover:', function() {
             x: 200,
             y: 247.5,
             extraText: 'r: −5<br>θ: 270°',
-            color: '#1f77b4'
+            color: '#1f77b4',
+            idealAlign: 'left'
         }
     }, {
         desc: 'works on reversed radial axis ranges',