From 9b8d376c8ed6cf7586610f842de0b64f54a75f85 Mon Sep 17 00:00:00 2001
From: Lucas Wojciechowski <lucas@mapbox.com>
Date: Mon, 11 Jul 2016 16:53:57 -0700
Subject: [PATCH] Don't silently drop error events

fixes #2447
---
 js/util/evented.js          | 9 ++++++++-
 test/js/style/style.test.js | 8 ++++++++
 test/js/ui/map.test.js      | 6 +++---
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/js/util/evented.js b/js/util/evented.js
index 53601daf9fe..9554859c3af 100644
--- a/js/util/evented.js
+++ b/js/util/evented.js
@@ -85,7 +85,14 @@ var Evented = {
      * @returns {Object} `this`
      */
     fire: function(type, data) {
-        if (!this.listens(type)) return this;
+        if (!this.listens(type)) {
+            // Error events are important for debugging and should not be
+            // silently dropped.
+            if (util.endsWith(type, 'error')) {
+                (console.trace || console.error)('Dropped "error" event: ', data);
+            }
+            return this;
+        }
 
         data = util.extend({}, data);
         util.extend(data, {type: type, target: this});
diff --git a/test/js/style/style.test.js b/test/js/style/style.test.js
index b7955aad044..2b2e9dfcedc 100644
--- a/test/js/style/style.test.js
+++ b/test/js/style/style.test.js
@@ -433,6 +433,10 @@ test('Style#removeSource', function(t) {
             style.addSource('source-id', source);
             style.removeSource('source-id');
 
+            // Bind a listener to prevent fallback Evented error reporting.
+            source.on('error',  function() {});
+            source.on('tile.error',  function() {});
+
             source.fire('load');
             source.fire('error');
             source.fire('change');
@@ -689,6 +693,10 @@ test('Style#removeLayer', function(t) {
         style.on('load', function() {
             var layer = style._layers.background;
             style.removeLayer('background');
+
+            // Bind a listener to prevent fallback Evented error reporting.
+            layer.on('error', function() {});
+
             layer.fire('error', {mapbox: true});
             t.end();
         });
diff --git a/test/js/ui/map.test.js b/test/js/ui/map.test.js
index 345a320999c..0f1b6bcc77b 100755
--- a/test/js/ui/map.test.js
+++ b/test/js/ui/map.test.js
@@ -150,7 +150,6 @@ test('Map', function(t) {
             style.fire('tile.add');
             style.fire('tile.error');
             style.fire('tile.remove');
-            style.fire('layer.error');
         });
 
         t.test('can be called more than once', function(t) {
@@ -750,7 +749,7 @@ test('Map', function(t) {
                     "sources": {
                         "mapbox://mapbox.satellite": {
                             "type": "raster",
-                            "tiles": ["local://tiles/{z}-{x}-{y}.png"]
+                            "tiles": ["http://example.com/{z}/{x}/{y}.png"]
                         }
                     },
                     "layers": [{
@@ -764,8 +763,9 @@ test('Map', function(t) {
                 }
             });
 
-            // We're faking tiles
+            // Suppress errors because we're not loading tiles from a real URL.
             map.off('tile.error', map.onError);
+            map.on('tile.error', function() {});
 
             map.on('style.load', function () {
                 map.setLayoutProperty('satellite', 'visibility', 'visible');