hacky handling for reshaped arrays in Plotly.react

Author: alexcjohnson

src/plot_api/plot_api.js

@@ -2490,6 +2490,13 @@ function getDiffFlags(oldContainer, newContainer, outerparts, opts) {
         }
         else if(canBeDataArray) {
             if(wasArray && nowArray) {
+                // hack for traces that modify the data in supplyDefaults, like
+                // converting 1D to 2D arrays, which will always create new objects
+                var inputKey = '_input_' + key;
+                var oldValIn = oldContainer[inputKey];
+                var newValIn = newContainer[inputKey];
+                if(Array.isArray(oldValIn) && oldValIn === newValIn) continue;
+
                 // don't try to diff two data arrays. If immutable we know the data changed,
                 // if not, assume it didn't and let `layout.datarevision` tell us if it did
                 if(immutable) {

src/traces/heatmap/convert_column_xyz.js

@@ -70,9 +70,13 @@ module.exports = function convertColumnData(trace, ax1, ax2, var1Name, var2Name,
         }
     }
 
+    // hack for Plotly.react - save the input arrays for diffing purposes
+    trace['_input_' + var1Name] = trace[var1Name];
+    trace['_input_' + var2Name] = trace[var2Name];
     trace[var1Name] = col1vals;
     trace[var2Name] = col2vals;
     for(j = 0; j < arrayVarNames.length; j++) {
+        trace['_input_' + arrayVarNames[j]] = trace[arrayVarNames[j]];
         trace[arrayVarNames[j]] = newArrays[j];
     }
     if(hasColumnText) trace.text = text;