absolute_url util (closes #9)

librefi/utils.py

@@ -1,7 +1,7 @@
 # flake8: noqa: E501
 
 import re
-from urllib.parse import parse_qs, quote as qs_quote
+from urllib.parse import parse_qs, quote as qs_quote, urlparse
 from datetime import datetime
 import random
 
@@ -131,3 +131,24 @@ def dump_qs(obj):
         strng += qs_quote(str(el[0]), encoding="utf8") + "=" + \
             qs_quote(str(el[1]), encoding="utf8") + "&"
     return strng[:-1]
+
+
+def absolute_url(new_url: str, old_url: str):
+    if new_url.startswith("http:") or new_url.startswith("https:"):
+        return new_url
+
+    old = urlparse(old_url)
+    scheme = old.scheme if old.scheme is not None else "http"
+
+    if new_url.startswith("://"):
+        return scheme + new_url
+    if new_url.startswith("//"):
+        return scheme + ":" + new_url
+
+    hostname = old.netloc
+
+    if new_url.startswith("/"):
+        return scheme + "://" + hostname + new_url
+
+    # like "hostname/path?query", if other checks fail
+    return scheme + "://" + new_url

tests/url_utils.py

@@ -0,0 +1,15 @@
+from librefi.utils import absolute_url
+
+OLD_URL = "https://sakamoto.pl/ddd"
+NEW_URL_RELATIVE = "/DDD?test=yes"
+
+# expected value
+NEW_URL_ABSOLUTE = "https://sakamoto.pl/DDD?test=yes"
+
+
+def test_basic():
+    abso = absolute_url(NEW_URL_RELATIVE, OLD_URL)
+    assert isinstance(abso, (str))
+    print(abso)
+    assert abso == NEW_URL_ABSOLUTE
+    pass