don't mutate dimensions[i].displayindex in calc

... so that Plotly.react works on parcats mocks that
    have "bad" displayindex values

Author: etpinard

src/traces/parcats/calc.js

@@ -160,7 +160,7 @@ module.exports = function calc(gd, trace) {
 
     // Array of DimensionModel objects
     var dimensionModels = trace.dimensions.filter(visible).map(function(di, i) {
-        return createDimensionModel(i, di._index, di.displayindex, di.label, totalCount);
+        return createDimensionModel(i, di._index, di._displayindex, di.label, totalCount);
     });
 
 
@@ -456,16 +456,23 @@ function getUniqueInfo(values, uniqueValues) {
 
 /**
  * Validate the requested display order for the dimensions.
- * If the display order is a permutation of 0 through dimensions.length - 1 then leave it alone. Otherwise, repalce
- * the display order with the dimension order
+ * If the display order is a permutation of 0 through dimensions.length - 1, link to _displayindex
+ * Otherwise, replace the display order with the dimension order
  * @param {Object} trace
  */
 function validateDimensionDisplayInds(trace) {
-    var displayInds = trace.dimensions.filter(visible).map(function(dim) {return dim.displayindex;});
-    if(!isRangePermutation(displayInds)) {
-        trace.dimensions.filter(visible).forEach(function(dim, i) {
-            dim.displayindex = i;
-        });
+    var visibleDims = Lib.filterVisible(trace.dimensions);
+    var displayInds = visibleDims.map(function(d) { return d.displayindex; });
+    var i;
+
+    if(isRangePermutation(displayInds)) {
+        for(i = 0; i < visibleDims.length; i++) {
+            visibleDims[i]._displayindex = visibleDims[i].displayindex;
+        }
+    } else {
+        for(i = 0; i < visibleDims.length; i++) {
+            visibleDims[i]._displayindex = i;
+        }
     }
 }
 

test/image/baselines/parcats_bad-displayindex.png

@@ -0,0 +1,17 @@
+{
+  "data": [
+    {"type": "parcats",
+      "dimensions": [
+        {"label": "One", "values": [1, 1, 2, 1, 2, 1, 1, 2, 1],
+          "displayindex": 1, "categoryarray": [1, 2], "ticktext": ["One", "Two"]},
+        {"label": "Two", "values": ["A", "B", "A", "B", "C", "C", "A", "B", "C"],
+          "displayindex": 2, "categoryarray": ["B", "A", "C"]},
+        {"label": "Three", "values": [11, 11, 11, 11, 11, 11, 11, 11, 11], "displayindex": 1}]}
+  ],
+  "layout": {
+    "height": 602,
+    "width": 592,
+    "margin": {
+      "l": 40, "r": 40, "t": 50, "b": 40
+    }}
+}

test/image/mocks/parcats_bad-displayindex.json

@@ -27,7 +27,7 @@ var svgMockList = [
     ['range_selector_style', require('@mocks/range_selector_style.json')],
     ['range_slider_multiple', require('@mocks/range_slider_multiple.json')],
     ['sankey_energy', require('@mocks/sankey_energy.json')],
-    ['parcats_basic', require('@mocks/parcats_basic.json')],
+    ['parcats_bad-displayindex', require('@mocks/parcats_bad-displayindex.json')],
     ['scattercarpet', require('@mocks/scattercarpet.json')],
     ['shapes', require('@mocks/shapes.json')],
     ['splom_iris', require('@mocks/splom_iris.json')],