Change the regex to have lookahed and lookbehinds so the match is more 'pure'

files/helpers/word_censor.py

@@ -43,12 +43,13 @@ def create_slur_regex() -> Pattern[str]:
     # words that can have suffixes and prefixes
     words = "|".join([slur.lower() for slur in SLURS.keys() if not slur.startswith(" ")])
 
-    regex = rf"(\s|>)({words})|({words})(\s|<)"
+    # to understand the weird groups see: https://www.regular-expressions.info/lookaround.html
+    regex = rf"(?<=\s|>)({words})|({words})(?=\s|<)"
 
     # words that need to match exactly
     single_words = "|".join([slur.strip().lower() for slur in SLURS.keys() if slur.startswith(" ")])
 
-    return re.compile(rf"(?i){regex}|(\s|>)({single_words})(\s|<)")
+    return re.compile(rf"(?i){regex}|(?<=\s|>)({single_words})(?=\s|<)")
 
 
 def create_replace_map() -> Dict[str, str]:
@@ -65,23 +66,13 @@ REPLACE_MAP = create_replace_map()
 
 def sub_matcher(match: Match) -> str:
     """given a match returns the correct replacer string"""
-
-    # base regex: (?i)(\s|>)(words)|(words)(\s|<)|(\s|>)(words)(\s|<)
-    if match.group(2) is not None:
-        found = match.group(2)
-    elif match.group(3) is not None:
-        found = match.group(3)
-    else:
-        found = match.group(6)
-
-    # if it does not find the correct capitalization, it tries the all lower
-    replacer = REPLACE_MAP.get(found) or REPLACE_MAP.get(found.lower())
-
-    return (match.group(1) or match.group(5) or '') + replacer + (match.group(4) or match.group(7) or '')
+    found = match.group(0)
+    # if it does not find the correct capitalization, it tries the all lower, or return the original word
+    return REPLACE_MAP.get(found) or REPLACE_MAP.get(found.lower()) or found
 
 
 def censor_slurs(body: str, logged_user) -> str:
-    """Censors all the slurs in the body if the user is not logged in or if they have the slurreplacer active"""
+    """Censors all the slurs in the body if the user is not logged-in or if they have the slurreplacer active"""
 
     if not logged_user or logged_user.slurreplacer:
         try:

test/files/helpers/test_word_censor.py

@@ -52,7 +52,7 @@ def test_get_permutations_slur_wiht_link_replacer():
     " retard ": "r-slur",
 })
 def test_create_slur_regex():
-    expected = r"(?i)(\s|>)(kill yourself|faggot)|(kill yourself|faggot)(\s|<)|(\s|>)(nig|retard)(\s|<)"
+    expected = r"(?i)(?<=\s|>)(kill yourself|faggot)|(kill yourself|faggot)(?=\s|<)|(?<=\s|>)(nig|retard)(?=\s|<)"
 
     assert_that(create_slur_regex()).is_equal_to(re.compile(expected))
 
@@ -91,22 +91,23 @@ def test_create_replace_map():
 
 @patch("files.helpers.word_censor.REPLACE_MAP", {'retard': 'r-slur', 'Faggot': 'Cute twink', 'NIG': '🏀'})
 def test_sub_matcher():
-    regex = re.compile(r"(?i)(\s|>)(kill yourself|retard)|(kill yourself|retard)(\s|<)|(\s|>)(nig|faggot)(\s|<)")
+    regex = re.compile(
+        r"(?i)(?<=\s|>)(kill yourself|retard)|(kill yourself|retard)(?=\s|<)|(?<=\s|>)(nig|faggot)(?=\s|<)")
 
     match = regex.search("<p>retard</p>")
-    assert_that(sub_matcher(match)).is_equal_to(">r-slur")
+    assert_that(sub_matcher(match)).is_equal_to("r-slur")
 
     match = regex.search("<p>noretard</p>")
-    assert_that(sub_matcher(match)).is_equal_to("r-slur<")
+    assert_that(sub_matcher(match)).is_equal_to("r-slur")
 
     match = regex.search("<p>ReTaRdEd</p>")
-    assert_that(sub_matcher(match)).is_equal_to(">r-slur")
+    assert_that(sub_matcher(match)).is_equal_to("r-slur")
 
     match = regex.search("<p>NIG</p>")
-    assert_that(sub_matcher(match)).is_equal_to(">🏀<")
+    assert_that(sub_matcher(match)).is_equal_to("🏀")
 
     match = regex.search("<p>Faggot </p>")
-    assert_that(sub_matcher(match)).is_equal_to(">Cute twink ")
+    assert_that(sub_matcher(match)).is_equal_to("Cute twink")
 
 
 @patch("files.helpers.word_censor.SLURS", {
@@ -163,6 +164,8 @@ def test_censor_slurs():
 @patch("files.helpers.word_censor.SLURS", {'retard': 'r-slur', 'manlet': 'little king', ' nig ': '🏀'})
 def test_censor_slurs_does_not_error_out_on_exception():
     word_censor.REPLACE_MAP = create_replace_map()
+    word_censor.SLUR_REGEX = create_slur_regex()
+    word_censor.REPLACE_MAP["manlet"] = None
     word_censor.REPLACE_MAP["Manlet"] = None
 
     assert_that(censor_slurs(">retarded SuperManlet NIG<", None)).is_equal_to(">r-slured SuperManlet 🏀<")
@@ -171,6 +174,7 @@ def test_censor_slurs_does_not_error_out_on_exception():
 @patch("files.helpers.word_censor.SLURS", {'retard': 'r-slur', 'manlet': 'little king'})
 def test_censor_slurs_does_not_censor_on_flag_disabled():
     word_censor.REPLACE_MAP = create_replace_map()
+    word_censor.SLUR_REGEX = create_slur_regex()
 
     class User:
         def __init__(self, slurreplacer):