Minmimum hashtag length for category learning

categories.py

@@ -262,11 +262,12 @@ def set_hashtag_category(base_dir: str, hashtag: str, category: str,
     return False
 
 
-def guess_hashtag_category(tag_name: str, hashtag_categories: {}) -> str:
+def guess_hashtag_category(tag_name: str, hashtag_categories: {},
+                           min_tag_length: int) -> str:
     """Tries to guess a category for the given hashtag.
     This works by trying to find the longest similar hashtag
     """
-    if len(tag_name) < 6:
+    if len(tag_name) < min_tag_length:
         return ''
 
     category_matched = ''
@@ -274,7 +275,7 @@ def guess_hashtag_category(tag_name: str, hashtag_categories: {}) -> str:
 
     for category_str, hashtag_list in hashtag_categories.items():
         for hashtag in hashtag_list:
-            if len(hashtag) < 6:
+            if len(hashtag) < min_tag_length:
                 # avoid matching very small strings which often
                 # lead to spurious categories
                 continue

inbox.py

@@ -440,7 +440,7 @@ def store_hash_tags(base_dir: str, nickname: str, domain: str,
             if not os.path.isfile(category_filename):
                 hashtag_categories = get_hashtag_categories(base_dir)
                 category_str = \
-                    guess_hashtag_category(tag_name, hashtag_categories)
+                    guess_hashtag_category(tag_name, hashtag_categories, 6)
                 if category_str:
                     set_hashtag_category(base_dir, tag_name,
                                          category_str, False)

tests.py

@@ -4838,10 +4838,10 @@ def _test_guess_tag_category() -> None:
         "foo": ["swan", "goose"],
         "bar": ["cats", "mouse"]
     }
-    guess = guess_hashtag_category("unspecifiedgoose", hashtag_categories)
+    guess = guess_hashtag_category("unspecifiedgoose", hashtag_categories, 4)
     assert guess == "foo"
 
-    guess = guess_hashtag_category("mastocats", hashtag_categories)
+    guess = guess_hashtag_category("mastocats", hashtag_categories, 4)
     assert guess == "bar"