Add option to ignore current line when trimming whitespace

lib/main.coffee

@@ -3,6 +3,7 @@ Whitespace = require './whitespace'
 module.exports =
   configDefaults:
     removeTrailingWhitespace: true
+    ignoreLeadingWhitespaceOnCurrentLine: true
     ensureSingleTrailingNewline: true
 
   activate: ->

lib/whitespace.coffee

@@ -16,20 +16,27 @@ class Whitespace
     @subscribe buffer, 'will-be-saved', =>
       buffer.transact =>
         if atom.config.get('whitespace.removeTrailingWhitespace')
-          @removeTrailingWhitespace(buffer, editor.getGrammar().scopeName)
+          @removeTrailingWhitespace(editor, editor.getGrammar().scopeName)
 
         if atom.config.get('whitespace.ensureSingleTrailingNewline')
           @ensureSingleTrailingNewline(buffer)
 
     @subscribe buffer, 'destroyed', =>
       @unsubscribe(buffer)
 
-  removeTrailingWhitespace: (buffer, grammarScopeName) ->
+  removeTrailingWhitespace: (editor, grammarScopeName) ->
+    buffer = editor.getBuffer()
+    ignoreCurLine = atom.config.get('whitespace.ignoreLeadingWhitespaceOnCurrentLine')
     buffer.scan /[ \t]+$/g, ({lineText, match, replace}) ->
+      whitespaceRow = buffer.positionForCharacterIndex(match.index).row
+      cursorRow = editor.getCursor().getBufferRow()
+      onlyWhitespace = lineText.match(/^[ \t]+$/)
       if grammarScopeName is 'source.gfm'
         # GitHub Flavored Markdown permits two spaces at the end of a line
         [whitespace] = match
         replace('') unless whitespace is '  ' and whitespace isnt lineText
+      else if ignoreCurLine and onlyWhitespace and whitespaceRow is cursorRow
+        # don't touch this line
       else
         replace('')
 

spec/whitespace-spec.coffee

@@ -52,6 +52,35 @@ describe "Whitespace", ->
     editor.save()
     expect(editor.getText()).toBe "don't trim me \n"
 
+  describe "whitespace.ignoreLeadingWhitespaceOnCurrentLine config", ->
+    [originalConfigValue] = []
+    beforeEach ->
+      originalConfigValue = atom.config.get("whitespace.ignoreLeadingWhitespaceOnCurrentLine")
+      expect(originalConfigValue).toBe true
+
+    afterEach ->
+      atom.config.set("whitespace.ignoreLeadingWhitespaceOnCurrentLine", originalConfigValue)
+
+    it "doesn't trim whitespace on current line", ->
+      editor.insertText "  "
+      editor.setCursorBufferPosition([0,2])
+      editor.save()
+      expect(editor.getText()).toBe "  \n"
+
+    it "does trim whitespace on other lines", ->
+      editor.insertText "  \n  "
+      editor.setCursorBufferPosition([0,2])
+      editor.save()
+      expect(editor.getText()).toBe "  \n"
+
+    it "trims whitespace on current line if ignoreLeadingWhitespaceOnCurrentLine is false", ->
+      atom.config.set("whitespace.ignoreLeadingWhitespaceOnCurrentLine", false)
+
+      editor.insertText "  "
+      editor.setCursorBufferPosition([0,2])
+      editor.save()
+      expect(editor.getText()).toBe "\n"
+
   describe "whitespace.ensureSingleTrailingNewline config", ->
     [originalConfigValue] = []
     beforeEach ->