Test contrasting inside text colors for standard pie colors [2951]

- Standard pie colors means no marker colors set explicitly.

Author: rmoestl

test/jasmine/tests/pie_test.js

@@ -542,13 +542,23 @@ describe('Pie traces', function() {
         }
     };
 
-    it('should use inside text colors contrasting to slice colors by default', function(done) {
+    it('should use inside text colors contrasting to explicitly set slice colors by default', function(done) {
         Plotly.plot(gd, [insideTextTestsTrace])
           .then(_checkFontColors([DARK, DARK, LIGHT, LIGHT, DARK, LIGHT]))
           .catch(failTest)
           .then(done);
     });
 
+    it('should use inside text colors contrasting to standard slice colors by default', function(done) {
+        var noMarkerTrace = Lib.extendFlat({}, insideTextTestsTrace);
+        delete noMarkerTrace.marker;
+
+        Plotly.plot(gd, [noMarkerTrace])
+          .then(_checkFontColors([LIGHT, DARK, LIGHT, LIGHT, LIGHT, LIGHT]))
+          .catch(failTest)
+          .then(done);
+    });
+
     it('should use textfont.color for inside text instead of the contrasting default', function(done) {
         var data = Lib.extendFlat({}, insideTextTestsTrace, {textfont: {color: 'red'}});
         Plotly.plot(gd, [data])