Lowercase current word/selection with meta-U

src/app/edit-session.coffee

@@ -314,6 +314,17 @@ class EditSession
   mutateSelectedText: (fn) ->
     @transact => fn(selection) for selection in @getSelections()
 
+  replaceSelectedText: (options={}, fn) ->
+    {selectWordIfEmpty} = options
+    @mutateSelectedText (selection) =>
+      range = selection.getBufferRange()
+      if selectWordIfEmpty and selection.isEmpty()
+        selection.selectWord()
+      text = selection.getText()
+      selection.delete()
+      selection.insertText(fn(text))
+      selection.setBufferRange(range)
+
   pushOperation: (operation) ->
     @buffer.pushOperation(operation, this)
 
@@ -553,14 +564,10 @@ class EditSession
         selection.insertText selection.getText().split('').reverse().join('')
 
   upperCase: ->
-    @mutateSelectedText (selection) =>
-      range = selection.getBufferRange()
-      if selection.isEmpty()
-        selection.selectWord()
-      text = selection.getText()
-      selection.delete()
-      selection.insertText text.toUpperCase()
-      selection.setBufferRange(range) if range
+    @replaceSelectedText selectWordIfEmpty:true, (text) => text.toUpperCase()
+
+  lowerCase: ->
+    @replaceSelectedText selectWordIfEmpty:true, (text) => text.toLowerCase()
 
   expandLastSelectionOverLine: ->
     @getLastSelection().expandOverLine()

src/app/editor.coffee

@@ -134,6 +134,7 @@ class Editor extends View
       'editor:select-to-beginning-of-word': @selectToBeginningOfWord
       'editor:transpose': @transpose
       'editor:upper-case': @upperCase
+      'editor:lower-case': @lowerCase
 
     unless @mini
       _.extend editorBindings,
@@ -228,6 +229,7 @@ class Editor extends View
   selectToScreenPosition: (position) -> @activeEditSession.selectToScreenPosition(position)
   transpose: -> @activeEditSession.transpose()
   upperCase: -> @activeEditSession.upperCase()
+  lowerCase: -> @activeEditSession.lowerCase()
   clearSelections: -> @activeEditSession.clearSelections()
 
   backspace: -> @activeEditSession.backspace()

src/app/keymaps/editor.cson

@@ -32,3 +32,4 @@
   'ctrl-W': 'editor:select-word'
   'meta-alt-p': 'editor:log-cursor-scope'
   'meta-u': 'editor:upper-case'
+  'meta-U': 'editor:lower-case'