Add the following features:

- If there is a comment at the end of the line, place the semicolon before the comment
- Don't place a semicolon if one is already present

AppendSemiColon.py

@@ -1,8 +1,36 @@
-import sublime_plugin;
+import sublime_plugin
 
 class AppendSemiColonCommand(sublime_plugin.TextCommand):
-	def run(self, edit):
-		for region in self.view.sel():
-			line_end = self.view.line(region).end()
-			if self.view.substr(line_end - 1) != ';':
-				self.view.insert(edit, line_end, ';')
+  def run(self, edit):
+
+    def insert_semicolon(point):
+      self.view.insert(edit, point, ';')
+
+    def is_semicolon(point):
+      return self.view.substr(point) == ';'
+
+    for region in self.view.sel():
+      line = self.view.line(region)
+      line_begin = line.begin()
+      line_end = line.end()
+
+      while(self.view.substr(line_end - 1).isspace() and line_end != line_begin): # go to the first character from the end that isn't whitespace
+        line_end -= 1
+
+      if line_end == line_begin:
+        continue
+
+      if self.view.match_selector(line_end - 1, 'comment'):
+        point = self.view.extract_scope(line_end - 1).a - 1
+
+        if point < line_begin:
+          continue
+
+        while(self.view.substr(point).isspace() and point != line_begin): # go to the first character before the comment that isn't whitespace
+          point -= 1
+
+        if not self.view.substr(point).isspace() and not is_semicolon(point):
+          insert_semicolon(point + 1)
+
+      elif not is_semicolon(line_end - 1):
+        insert_semicolon(line_end)