Add Blob#indexable?

lib/linguist/blob_helper.rb

@@ -86,9 +86,23 @@ module Linguist
       end
     end
 
+    def indexable?
+      if !text?
+        false
+      elsif generated?
+        false
+      elsif ['.po', '.sql'].include?(pathname.extname)
+        false
+      elsif Language.find_by_extension(pathname.extname)
+        true
+      else
+        false
+      end
+    end
+
     def language
       if text?
-        if pathname.extname == ""
+        if !Language.find_by_extension(pathname.extname)
           shebang_language || pathname.language
         else
           pathname.language

test/test_blob.rb

@@ -127,6 +127,15 @@ class TestBlob < Test::Unit::TestCase
     assert blob("public/javascripts/dragdrop.js").vendored?
   end
 
+  def test_indexable
+    assert blob("file.txt").indexable?
+    assert blob("file.rb").indexable?
+    assert !blob("defun.kt").indexable?
+    assert !blob("github.po").indexable?
+    assert !blob("dump.sql").indexable?
+    assert !blob("linguist.gem").indexable?
+  end
+
   def test_language
     assert_equal Language['Ruby'], blob("foo.rb").language
     assert_equal Language['Ruby'], blob("script.rb").language