safety: fix safeify_url() exception on python 3.11

sopel/builtins/safety.py

@@ -126,11 +126,15 @@ def setup(bot: Sopel) -> None:
 
 def safeify_url(url: str) -> str:
     """Replace bits of a URL to make it hard to browse to."""
-    parts = urlparse(url)
-    scheme = "hxx" + parts.scheme[3:]  # hxxp
-    netloc = parts.netloc.replace(".", "[.]")  # google[.]com and IPv4
-    netloc = netloc.replace(":", "[:]")  # IPv6 addresses (bad lazy method)
-    return urlunparse((scheme, netloc) + parts[2:])
+    try:
+        parts = urlparse(url)
+        scheme = parts.scheme.replace("t", "x")  # hxxp
+        netloc = parts.netloc.replace(".", "[.]")  # google[.]com and IPv4
+        netloc = netloc.replace(":", "[:]")  # IPv6 addresses (bad lazy method)
+        return urlunparse((scheme, netloc) + parts[2:])
+    except ValueError:
+        # Still try to defang URLs that fail parsing
+        return url.replace(":", "[:]").replace(".", "[.]")
 
 
 def download_domain_list(bot: Sopel, path: str) -> bool:
@@ -224,7 +228,6 @@ def url_handler(bot: SopelWrapper, trigger: Trigger) -> None:
     strict = "strict" in mode
 
     for url in tools.web.search_urls(trigger):
-        safe_url = safeify_url(url)
 
         positives = 0  # Number of engines saying it's malicious
         total = 0  # Number of total engines
@@ -249,6 +252,7 @@ def url_handler(bot: SopelWrapper, trigger: Trigger) -> None:
 
         if positives >= 1:
             # Possibly malicious URL detected!
+            safe_url = safeify_url(url)
             LOGGER.info(
                 "Possibly malicious link (%s/%s) posted in %s by %s: %r",
                 positives,
@@ -258,11 +262,10 @@ def url_handler(bot: SopelWrapper, trigger: Trigger) -> None:
                 safe_url,
             )
             bot.say(
-                "{} {} of {} engine{} flagged a link {} posted as malicious".format(
+                "{} {} of {} engines flagged a link {} posted as malicious".format(
                     bold(color("WARNING:", colors.RED)),
                     positives,
                     total,
-                    "" if total == 1 else "s",
                     bold(trigger.nick),
                 )
             )

test/builtins/test_builtins_safety.py

@@ -0,0 +1,27 @@
+"""Tests for Sopel's ``safety`` plugin"""
+
+from __future__ import annotations
+
+import pytest
+
+from sopel.builtins.safety import safeify_url
+
+URL_TESTS = (
+    # Valid URLs
+    ("http://example.com", ("hxxp://example[.]com")),
+    ("http://1.2.3.4/mgr.cgi", ("hxxp://1[.]2[.]3[.]4/mgr.cgi")),
+    ("http://[fd00:1234::4321]/", ("hxxp://[fd00[:]1234[:][:]4321]/")),
+    ("ftp://1.2.3.4/", ("fxp://1[.]2[.]3[.]4/")),
+    # Invalid, but parsed anyway
+    ("http://<placeholder>/", ("hxxp://<placeholder>/")),
+    ("http://1.2.3.4.5/", ("hxxp://1[.]2[.]3[.]4[.]5/")),
+    ("http://555.555.555.555/", ("hxxp://555[.]555[.]555[.]555/")),
+    # urllib.urlparse() works on these in python <=3.10 but fails in 3.11
+    ("http://[fd00:::]/", ("hxxp://[fd00[:][:][:]]/", "http[:]//[fd00[:][:][:]]/")),
+    ("http://[placeholder]/", ("hxxp://[placeholder]/", "http[:]//[placeholder]/")),
+)
+
+
+@pytest.mark.parametrize("original, safed_options", URL_TESTS)
+def test_safeify_url(original, safed_options):
+    assert safeify_url(original) in safed_options