Fuzzy search issuable title or description

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/gitlab/sql/pattern.rb b/lib/gitlab/sql/pattern.rb
index b42bc67ccfc..7c2d1d8f887 100644
--- a/lib/gitlab/sql/pattern.rb
+++ b/lib/gitlab/sql/pattern.rb
@@ -4,6 +4,7 @@ module Gitlab
       extend ActiveSupport::Concern
 
       MIN_CHARS_FOR_PARTIAL_MATCHING = 3
+      REGEX_QUOTED_WORD = /(?<=^| )"[^"]+"(?= |$)/
 
       class_methods do
         def to_pattern(query)
@@ -17,6 +18,28 @@ module Gitlab
         def partial_matching?(query)
           query.length >= MIN_CHARS_FOR_PARTIAL_MATCHING
         end
+
+        def to_fuzzy_arel(column, query)
+          words = select_fuzzy_words(query)
+
+          matches = words.map { |word| arel_table[column].matches(to_pattern(word)) }
+
+          matches.reduce { |result, match| result.and(match) }
+        end
+
+        def select_fuzzy_words(query)
+          quoted_words = query.scan(REGEX_QUOTED_WORD)
+
+          query = quoted_words.reduce(query) { |q, quoted_word| q.sub(quoted_word, '') }
+
+          words = query.split(/\s+/)
+
+          quoted_words.map! { |quoted_word| quoted_word[1..-2] }
+
+          words.concat(quoted_words)
+
+          words.select { |word| partial_matching?(word) }
+        end
       end
     end
   end