Wrap around file instead of beeping

This mirrors the behavior of find-and-replace, wrap around
to the beginning/end of the file to find the next/previous diff.

Closes #8

Author: kevinsawicki

Diff for: lib/git-diff-view.coffee

@@ -39,30 +39,40 @@ class GitDiffView
   moveToNextDiff: ->
     cursorLineNumber = @editor.getCursorBufferPosition().row + 1
     nextDiffLineNumber = null
+    firstDiffLineNumber = null
     hunks = @diffs[@editor.getPath()] ? []
-    for {newStart} in hunks when newStart > cursorLineNumber
-      if nextDiffLineNumber?
+    for {newStart} in hunks
+      if newStart > cursorLineNumber
+        nextDiffLineNumber ?= newStart - 1
         nextDiffLineNumber = Math.min(newStart - 1, nextDiffLineNumber)
-      else
-        nextDiffLineNumber = newStart - 1
+
+      firstDiffLineNumber ?= newStart - 1
+      firstDiffLineNumber = Math.min(newStart - 1, firstDiffLineNumber)
+
+    # Wrap around to the first diff in the file
+    nextDiffLineNumber = firstDiffLineNumber unless nextDiffLineNumber?
 
     @moveToLineNumber(nextDiffLineNumber)
 
   moveToPreviousDiff: ->
     cursorLineNumber = @editor.getCursorBufferPosition().row + 1
     previousDiffLineNumber = -1
+    lastDiffLineNumber = -1
     hunks = @diffs[@editor.getPath()] ? []
-    for {newStart} in hunks when newStart < cursorLineNumber
-      previousDiffLineNumber = Math.max(newStart - 1, previousDiffLineNumber)
+    for {newStart} in hunks
+      if newStart < cursorLineNumber
+        previousDiffLineNumber = Math.max(newStart - 1, previousDiffLineNumber)
+      lastDiffLineNumber = Math.max(newStart - 1, lastDiffLineNumber)
+
+    # Wrap around to the last diff in the file
+    previousDiffLineNumber = lastDiffLineNumber if previousDiffLineNumber is -1
 
     @moveToLineNumber(previousDiffLineNumber)
 
   moveToLineNumber: (lineNumber=-1) ->
     if lineNumber >= 0
       @editor.setCursorBufferPosition([lineNumber, 0])
       @editor.moveCursorToFirstCharacterOfLine()
-    else
-      atom.beep()
 
   unsubscribeFromBuffer: ->
     if @buffer?

Diff for: spec/git-diff-spec.coffee

@@ -83,13 +83,21 @@ describe "GitDiff package", ->
       editorView.trigger 'git-diff:move-to-next-diff'
       expect(editor.getCursorBufferPosition()).toEqual [4, 4]
 
-      spyOn(atom, 'beep')
+      editorView.trigger 'git-diff:move-to-previous-diff'
+      expect(editor.getCursorBufferPosition()).toEqual [0, 0]
+
+    it "wraps around to the first/last diff in the file", ->
+      editor.insertText('a')
+      editor.setCursorBufferPosition([5])
+      editor.deleteLine()
+      advanceClock(editor.getBuffer().stoppedChangingDelay)
+
+      editor.setCursorBufferPosition([0])
       editorView.trigger 'git-diff:move-to-next-diff'
-      expect(atom.beep.callCount).toBe 1
+      expect(editor.getCursorBufferPosition()).toEqual [4, 4]
 
-      editorView.trigger 'git-diff:move-to-previous-diff'
+      editorView.trigger 'git-diff:move-to-next-diff'
       expect(editor.getCursorBufferPosition()).toEqual [0, 0]
 
-      atom.beep.reset()
       editorView.trigger 'git-diff:move-to-previous-diff'
-      expect(atom.beep.callCount).toBe 1
+      expect(editor.getCursorBufferPosition()).toEqual [4, 4]