refactor: update impl of format_url (#1163)

src/django_components/util/misc.py

@@ -161,19 +161,10 @@ def format_url(url: str, query: Optional[Dict] = None, fragment: Optional[str] =
 
     `query` and `fragment` are optional, and not applied if `None`.
     """
-    url_parts = parse.urlsplit(url)
+    parts = parse.urlsplit(url)
+    fragment_enc = parse.quote(fragment or parts.fragment, safe="")
+    base_qs = dict(parse.parse_qsl(parts.query))
+    merged = {**base_qs, **(query or {})}
+    encoded_qs = parse.urlencode(merged, safe="")
 
-    escaped_fragment = parse.quote(str(fragment)) if fragment is not None else url_parts.fragment
-
-    # NOTE: parse_qsl returns a list of tuples. For simpicity we support only one
-    # value per key, so we need to unpack the first element.
-    query_from_url = {key: val[0] for key, val in parse.parse_qsl(url_parts.query)}
-    all_params = {**query_from_url, **(query or {})}
-
-    encoded_params = parse.urlencode(all_params)
-    updated_parts = url_parts._replace(
-        query=encoded_params,
-        fragment=escaped_fragment,
-    )
-    new_url = parse.urlunsplit(updated_parts)
-    return new_url
+    return parse.urlunsplit(parts._replace(query=encoded_qs, fragment=fragment_enc))

tests/test_component_view.py

@@ -9,6 +9,7 @@ from django.urls import path
 
 from django_components import Component, ComponentView, get_component_url, register, types
 from django_components.urls import urlpatterns as dc_urlpatterns
+from django_components.util.misc import format_url
 
 from django_components.testing import djc_test
 from .testutils import setup_test_config
@@ -315,6 +316,14 @@ class TestComponentAsView(SimpleTestCase):
         component_url3 = get_component_url(TestComponent, query={"f'oo": "b ar&ba'z"}, fragment='q u"x')
         assert component_url3 == f"/components/ext/view/components/{TestComponent.class_id}/?f%27oo=b+ar%26ba%27z#q%20u%22x"  # noqa: E501
 
+        # Merges query params from original URL
+        component_url4 = format_url(
+            "/components/ext/view/components/123?foo=123&bar=456#abc",
+            query={"foo": "new", "baz": "new2"},
+            fragment='xyz',
+        )
+        assert component_url4 == "/components/ext/view/components/123?foo=new&bar=456&baz=new2#xyz"
+
     def test_public_url(self):
         did_call_get = False
         did_call_post = False