change logic to urlparse & update doctests

Signed-off-by: mathioud <georgios.mathioudakis@here.com>

Author: mathioud

src/python_inspector/utils_pypi.py

@@ -20,7 +20,8 @@
 from typing import List
 from typing import NamedTuple
 from urllib.parse import quote_plus
-from urllib.parse import urljoin
+from urllib.parse import urlparse
+from urllib.parse import urlunparse
 
 import attr
 import packageurl
@@ -1595,29 +1596,34 @@ def fetch_links(
             url, _, _sha256 = anchor_tag["href"].partition("#sha256=")
             if "data-requires-python" in anchor_tag.attrs:
                 python_requires = anchor_tag.attrs["data-requires-python"]
-            url = resolve_relative_url(package_url, url)  # Resolve relative URL
+            # Resolve relative URL
+            url = resolve_relative_url(package_url, url)
             links.append(Link(url=url, python_requires=python_requires))
         # TODO: keep sha256
         return links
 
 
 def resolve_relative_url(package_url, url):
     """
-    Resolve a relative URL using the package URL.
+    Return the resolved `url` URLstring given a `package_url` base URL string
+    of a package.
 
-    Args:
-        package_url (str): The base URL of the package.
-        url (str): The URL to be resolved.
-
-    Returns:
-        str: The resolved URL.
-    Examples:
-        >>> resolve_relative_url("https://example.com/package", "../path/file.txt")
-        'https://example.com/path/file.txt'
+    For example:
+    >>> resolve_relative_url("https://example.com/package", "../path/file.txt")
+    'https://example.com/path/file.txt'
     """
     if not url.startswith(("http://", "https://")):
-        base_url = "/".join(package_url.split("/")[:-1])  # Extract base URL
-        url = urljoin(base_url, url)  # Resolve relative URL
+        base_url_parts = urlparse(package_url)
+        url_parts = urlparse(url)
+        # If the relative URL starts with '..', remove the last directory from the base URL
+        if url_parts.path.startswith(".."):
+            path = base_url_parts.path.rstrip("/").rsplit("/", 1)[0] + url_parts.path[2:]
+        else:
+            path = urlunparse(
+                ("", "", url_parts.path, url_parts.params, url_parts.query, url_parts.fragment)
+            )
+        resolved_url_parts = base_url_parts._replace(path=path)
+        url = urlunparse(resolved_url_parts)
     return url