[search_helpers] add Fuzzy search and stop using must

search_helpers.py

@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-from elasticsearch_dsl import Q
+from elasticsearch_dsl import Q, query as dsl_query
 
 from logilab.mtconverter import xml_escape
 
@@ -41,7 +41,6 @@
     must = []
     must_not = []
     should = []
-
     elements = query.split()
     elements_lowercase = [e.lower() for e in elements]
     if 'or' in elements_lowercase and len(elements) >= 3:
@@ -69,9 +68,10 @@
                               fields=fields))
 
         else:
-            must.append(Q('multi_match',
-                          query=element,
-                          fields=fields))
+            should.append(Q('multi_match',
+                            query=element,
+                            fields=fields))
+            should.append(dsl_query.Fuzzy(_all=element))
     return search.query('bool',
                         must=must,
                         must_not=must_not,