Assert CodeMirror modes and mime types are valid against source

lib/linguist/language.rb

@@ -302,7 +302,7 @@ module Linguist
 
       @ace_mode = attributes[:ace_mode]
       @codemirror_mode = attributes[:codemirror_mode]
-      @codemirror_mime_mode = attributes[:codemirror_mime_mode]
+      @codemirror_mime_type = attributes[:codemirror_mime_type]
       @wrap = attributes[:wrap] || false
 
       # Set legacy search term
@@ -423,7 +423,7 @@ module Linguist
     #  # => "text/x-csrc"
     #
     # Returns a String name or nil
-    attr_reader :codemirror_mime_mode
+    attr_reader :codemirror_mime_type
 
     # Public: Should language lines be wrapped
     #
@@ -602,7 +602,7 @@ module Linguist
       :tm_scope          => options['tm_scope'],
       :ace_mode          => options['ace_mode'],
       :codemirror_mode   => options['codemirror_mode'],
-      :codemirror_mime_mode => options['codemirror_mime_mode'],
+      :codemirror_mime_type => options['codemirror_mime_type'],
       :wrap              => options['wrap'],
       :group_name        => options['group'],
       :searchable        => options.fetch('searchable', true),