Remove event listeners from orphaned gutters

spec/text-editor-component-spec.coffee

@@ -743,6 +743,16 @@ describe "TextEditorComponent", ->
         beforeEach ->
           gutterNode = componentNode.querySelector('.gutter')
 
+        describe "when the component is destroyed", ->
+          it "stops listening for folding events", ->
+            component.destroy()
+
+            lineNumber = component.lineNumberNodeForScreenRow(1)
+            target = lineNumber.querySelector('.icon-right')
+            target.dispatchEvent(buildClickEvent(target))
+
+            expect(nextAnimationFrame).toBe(noAnimationFrame)
+
         it "folds and unfolds the block represented by the fold indicator when clicked", ->
           expect(lineNumberHasClass(1, 'folded')).toBe false
 
@@ -1727,6 +1737,14 @@ describe "TextEditorComponent", ->
     beforeEach ->
       gutterNode = componentNode.querySelector('.gutter')
 
+    describe "when the component is destroyed", ->
+      it "stops listening for selection events", ->
+        component.destroy()
+
+        gutterNode.dispatchEvent(buildMouseEvent('mousedown', clientCoordinatesForScreenRowInGutter(1)))
+
+        expect(editor.getSelectedScreenRange()).toEqual [[0, 0], [0, 0]]
+
     describe "when the gutter is clicked", ->
       it "selects the clicked row", ->
         gutterNode.dispatchEvent(buildMouseEvent('mousedown', clientCoordinatesForScreenRowInGutter(4)))

src/gutter-container-component.coffee

@@ -16,7 +16,12 @@ class GutterContainerComponent
 
     @domNode = document.createElement('div')
     @domNode.classList.add('gutter-container')
-    @domNode.style.display = 'flex';
+    @domNode.style.display = 'flex'
+
+  destroy: ->
+    for {name, component} in @gutterComponents
+      component.destroy?()
+    return
 
   getDomNode: ->
     @domNode

src/line-number-gutter-component.coffee

@@ -18,6 +18,10 @@ class LineNumberGutterComponent
     @domNode.addEventListener 'click', @onClick
     @domNode.addEventListener 'mousedown', @onMouseDown
 
+  destroy: ->
+    @domNode.removeEventListener 'click', @onClick
+    @domNode.removeEventListener 'mousedown', @onMouseDown
+
   getDomNode: ->
     @domNode
 

src/text-editor-component.coffee

@@ -106,6 +106,7 @@ class TextEditorComponent
     @mounted = false
     @disposables.dispose()
     @presenter.destroy()
+    @gutterContainerComponent?.destroy()
     window.removeEventListener 'resize', @requestHeightAndWidthMeasurement
 
   getDomNode: ->