add "matches" + "scaleanchor" mock

Author: etpinard

src/plot_api/subroutines.js

@@ -708,6 +708,8 @@ exports.doAutoRangeAndConstraints = function(gd) {
         doAutoRange(gd, ax);
     }
 
+    enforceAxisConstraints(gd);
+
     // TODO bypass this when matching axes aren't autoranged?
     for(var j = 0; j < matchGroups.length; j++) {
         var group = matchGroups[j];
@@ -737,9 +739,6 @@ exports.doAutoRangeAndConstraints = function(gd) {
             ax.setScale(0);
         }
     }
-
-    // TODO before or after matching axes?
-    enforceAxisConstraints(gd);
 };
 
 // An initial paint must be completed before these components can be

src/plots/cartesian/constraints.js

@@ -81,8 +81,6 @@ exports.handleConstraintDefaults = function(containerIn, containerOut, coerce, a
         found = true;
     }
 
-    // TODO what happens when both scaleanchor and matches are present???
-
     if(matches) {
         updateConstraintGroups(matchGroups, opts.thisGroup, thisID, matches, 1);
         found = true;

test/image/baselines/axes_scaleanchor-with-matches.png

@@ -0,0 +1,28 @@
+{
+  "data":[
+    {"x": [0,1,1,0,0,1,1,2,2,3,3,2,2,3], "y": [0,0,1,1,3,3,2,2,3,3,1,1,0,0]},
+    {"x": [0,1,2,3], "y": [1,2,4,8], "yaxis":"y2"}
+  ],
+  "layout":{
+    "width": 500,
+    "height": 500,
+    "xaxis": {
+        "constrain": "domain"
+    },
+    "yaxis": {
+        "scaleanchor": "x",
+        "constrain": "domain",
+        "domain": [0, 0.45],
+        "title": {"text": "1:1<br>matching y range above"}
+    },
+    "yaxis2": {
+        "matches": "y",
+        "constrain": "domain",
+        "scaleanchor": "x",
+        "scaleratio": 0.2,
+        "domain": [0.55, 1],
+        "title": {"text": "1:5<br>matching y range below"}
+    },
+    "showlegend": false
+  }
+}