Use set operations in suggest_similar_tag method; add tests (#230)

* Use set operations in suggest_similar_tag method; add tests

* remove extra blank line

buku.py

@@ -1537,41 +1537,36 @@ class BukuDb:
             return tagstr
 
         qry = 'SELECT DISTINCT tags FROM bookmarks WHERE tags LIKE ?'
-        tagset = []
-        unique_tags = []
+        tagset = set()
         for tag in tags:
             if tag == '':
                 continue
 
             self.cur.execute(qry, ('%' + delim_wrap(tag) + '%',))
             results = self.cur.fetchall()
-            if results:
-                for row in results:
-                    tagset += row[0].strip(DELIM).split(DELIM)
+            for row in results:
+                # update tagset with unique tags in row
+                tagset |= set(row[0].strip(DELIM).split(DELIM))
 
-        if len(tagset):
-            for tag in tagset:
-                if tag not in tags and tag not in unique_tags:
-                    unique_tags += (tag, )
+        # remove user supplied tags from tagset
+        tagset.difference_update(tags)
 
-        if not len(unique_tags):
+        if not len(tagset):
             return tagstr
 
-        unique_tags = sorted(unique_tags)
+        unique_tags = sorted(tagset)
+
         print('similar tags:\n')
-        count = 0
-        for tag in unique_tags:
+        for count, tag in enumerate(unique_tags):
             print('%d. %s' % (count + 1, unique_tags[count]))
-            count += 1
 
-        resp = input('\nselect: ')
+        selected_tags = input('\nselect: ').split()
         print()
-        if not resp:
+        if not selected_tags:
             return tagstr
 
-        tagset = resp.split()
         tags = [tagstr]
-        for index in tagset:
+        for index in selected_tags:
             try:
                 tags.append(delim_wrap(unique_tags[int(index) - 1]))
             except Exception as e:

tests/test_bukuDb.py

@@ -159,6 +159,22 @@ class TestBukuDb(unittest.TestCase):
 
         # TODO: tags should be passed to the api as a sequence...
 
+    def test_suggest_tags(self):
+        for bookmark in self.bookmarks:
+            self.bdb.add_rec(*bookmark)
+
+        tagstr = ',test,old,'
+        with mock.patch('builtins.input', return_value='1 2 3'):
+            expected_results = ',es,est,news,old,test,'
+            suggested_results = self.bdb.suggest_similar_tag(tagstr)
+            self.assertEqual(expected_results, suggested_results)
+
+        # returns user supplied tags if none are in the DB
+        tagstr = ',uniquetag1,uniquetag2,'
+        expected_results = tagstr
+        suggested_results = self.bdb.suggest_similar_tag(tagstr)
+        self.assertEqual(expected_results, suggested_results)
+
     # @unittest.skip('skipping')
     def test_update_rec(self):
         old_values = self.bookmarks[0]