From dd2f1e47eb87cb1f5cccd15c11327d3fbc08177d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89tienne=20T=C3=A9treault-Pinard?= <etienne@plot.ly>
Date: Wed, 10 Apr 2019 08:55:30 -0400
Subject: [PATCH 1/2] don't try to call doneFnCompleted when it isn't set

---
 src/plots/cartesian/select.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/plots/cartesian/select.js b/src/plots/cartesian/select.js
index 2a55961d6bd..742f9e8c3e9 100644
--- a/src/plots/cartesian/select.js
+++ b/src/plots/cartesian/select.js
@@ -49,8 +49,6 @@ function prepSelect(e, startX, startY, dragOptions, mode) {
     var allAxes = dragOptions.xaxes.concat(dragOptions.yaxes);
     var subtract = e.altKey;
 
-    var doneFnCompleted = dragOptions.doneFnCompleted;
-
     var filterPoly, selectionTester, mergedPolygons, currentPolygon;
     var i, searchInfo, eventData;
 
@@ -288,7 +286,9 @@ function prepSelect(e, startX, startY, dragOptions, mode) {
                 [].push.apply(dragOptions.mergedPolygons, mergedPolygons);
             }
 
-            doneFnCompleted(selection);
+            if(dragOptions.doneFnCompleted) {
+                dragOptions.doneFnCompleted(selection);
+            }
         });
     };
 }

From 98563547a97bf94bb60976b04f29ec46b27d992c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89tienne=20T=C3=A9treault-Pinard?= <etienne@plot.ly>
Date: Wed, 10 Apr 2019 16:28:07 -0400
Subject: [PATCH 2/2] log error during select throttle doneFn promise

... and spyOn of Lib.error to lock down #3755
---
 src/plots/cartesian/select.js     | 5 +++--
 test/jasmine/tests/select_test.js | 2 ++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/plots/cartesian/select.js b/src/plots/cartesian/select.js
index 742f9e8c3e9..fd8d3479772 100644
--- a/src/plots/cartesian/select.js
+++ b/src/plots/cartesian/select.js
@@ -15,6 +15,7 @@ var Registry = require('../../registry');
 var Color = require('../../components/color');
 var Fx = require('../../components/fx');
 
+var Lib = require('../../lib');
 var polygon = require('../../lib/polygon');
 var throttle = require('../../lib/throttle');
 var makeEventData = require('../../components/fx/helpers').makeEventData;
@@ -266,7 +267,7 @@ function prepSelect(e, startX, startY, dragOptions, mode) {
             }
 
             Fx.click(gd, evt);
-        });
+        }).catch(Lib.error);
     };
 
     dragOptions.doneFn = function() {
@@ -289,7 +290,7 @@ function prepSelect(e, startX, startY, dragOptions, mode) {
             if(dragOptions.doneFnCompleted) {
                 dragOptions.doneFnCompleted(selection);
             }
-        });
+        }).catch(Lib.error);
     };
 }
 
diff --git a/test/jasmine/tests/select_test.js b/test/jasmine/tests/select_test.js
index 2b015e00a42..1bc48e0fd3c 100644
--- a/test/jasmine/tests/select_test.js
+++ b/test/jasmine/tests/select_test.js
@@ -1597,6 +1597,7 @@ describe('Test select box and lasso per trace:', function() {
 
     beforeEach(function() {
         gd = createGraphDiv();
+        spyOn(Lib, 'error');
     });
 
     afterEach(destroyGraphDiv);
@@ -1716,6 +1717,7 @@ describe('Test select box and lasso per trace:', function() {
             .then(eventCounts[2] ? deselectPromise : Promise.resolve())
             .then(function() {
                 assertEventCounts(eventCounts[0], eventCounts[1], eventCounts[2], msg + ' (after dblclick)');
+                expect(Lib.error).not.toHaveBeenCalled();
             });
     }