From 17f12c42d33e4ba7af205c9d8f46913fa8be3743 Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevin@github.com>
Date: Wed, 23 Jan 2013 13:30:35 -0800
Subject: [PATCH] Delete end pair when begin pair is backspaced

---
 spec/app/language-mode-spec.coffee |  9 +++++++++
 src/app/language-mode.coffee       | 14 ++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/spec/app/language-mode-spec.coffee b/spec/app/language-mode-spec.coffee
index 340f4865c..dabd480d3 100644
--- a/spec/app/language-mode-spec.coffee
+++ b/spec/app/language-mode-spec.coffee
@@ -174,6 +174,15 @@ describe "LanguageMode", ->
             expect(buffer.lineForRow(0)).toBe "\"\""
             expect(editSession.getCursorBufferPosition()).toEqual [0, 1]
 
+    describe "bracket deletion", ->
+      it "deletes the end bracket when it directly proceeds a begin bracket that is being backspaced", ->
+        buffer.setText("")
+        editSession.setCursorBufferPosition([0, 0])
+        editSession.insertText '{'
+        expect(buffer.lineForRow(0)).toBe "{}"
+        editSession.backspace()
+        expect(buffer.lineForRow(0)).toBe ""
+
   describe "javascript", ->
     beforeEach ->
       editSession = fixturesProject.buildEditSessionForPath('sample.js', autoIndent: false)
diff --git a/src/app/language-mode.coffee b/src/app/language-mode.coffee
index 66caed8da..4afbee747 100644
--- a/src/app/language-mode.coffee
+++ b/src/app/language-mode.coffee
@@ -47,6 +47,20 @@ class LanguageMode
         @bracketAnchorRanges.push @editSession.addAnchorRange(range)
         false
 
+    _.adviseBefore @editSession, 'backspace', =>
+      return if @editSession.hasMultipleCursors()
+      return unless @editSession.getSelection().isEmpty()
+
+      cursorBufferPosition = @editSession.getCursorBufferPosition()
+      previousCharacter = @editSession.getTextInBufferRange([cursorBufferPosition.add([0, -1]), cursorBufferPosition])
+      nextCharacter = @editSession.getTextInBufferRange([cursorBufferPosition, cursorBufferPosition.add([0,1])])
+      if @pairedCharacters[previousCharacter] is nextCharacter
+        @editSession.transact =>
+          @editSession.moveCursorLeft()
+          @editSession.delete()
+          @editSession.delete()
+        false
+
   reloadGrammar: ->
     path = @buffer.getPath()
     pathContents = @buffer.cachedDiskContents