Fixed #25582 -- Added support for query and fragment to django.urls.reverse().

AUTHORS

@@ -146,6 +146,7 @@ answer newbie questions, and generally made Django that much better:
     Batman
     Batuhan Taskaya <batuhanosmantaskaya@gmail.com>
     Baurzhan Ismagulov <ibr@radix50.net>
+    Ben Cardy <me@bencardy.co.uk>
     Ben Dean Kawamura <ben.dean.kawamura@gmail.com>
     Ben Firshman <ben@firshman.co.uk>
     Ben Godfrey <http://aftnn.org>

django/urls/base.py

@@ -1,7 +1,8 @@
-from urllib.parse import unquote, urlsplit, urlunsplit
+from urllib.parse import unquote, urlencode, urlsplit, urlunsplit
 
 from asgiref.local import Local
 
+from django.http import QueryDict
 from django.utils.functional import lazy
 from django.utils.translation import override
 
@@ -24,7 +25,16 @@ def resolve(path, urlconf=None):
     return get_resolver(urlconf).resolve(path)
 
 
-def reverse(viewname, urlconf=None, args=None, kwargs=None, current_app=None):
+def reverse(
+    viewname,
+    urlconf=None,
+    args=None,
+    kwargs=None,
+    current_app=None,
+    *,
+    query=None,
+    fragment=None,
+):
     if urlconf is None:
         urlconf = get_urlconf()
     resolver = get_resolver(urlconf)
@@ -85,7 +95,17 @@ def reverse(viewname, urlconf=None, args=None, kwargs=None, current_app=None):
                 ns_pattern, resolver, tuple(ns_converters.items())
             )
 
-    return resolver._reverse_with_prefix(view, prefix, *args, **kwargs)
+    resolved_url = resolver._reverse_with_prefix(view, prefix, *args, **kwargs)
+    if query is not None:
+        if isinstance(query, QueryDict):
+            query_string = query.urlencode()
+        else:
+            query_string = urlencode(query, doseq=True)
+        if query_string:
+            resolved_url += "?" + query_string
+    if fragment is not None:
+        resolved_url += "#" + fragment
+    return resolved_url
 
 
 reverse_lazy = lazy(reverse, str)

docs/ref/urlresolvers.txt

@@ -10,7 +10,7 @@
 The ``reverse()`` function can be used to return an absolute path reference
 for a given view and optional parameters, similar to the :ttag:`url` tag:
 
-.. function:: reverse(viewname, urlconf=None, args=None, kwargs=None, current_app=None)
+.. function:: reverse(viewname, urlconf=None, args=None, kwargs=None, current_app=None, *, query=None, fragment=None)
 
 ``viewname`` can be a :ref:`URL pattern name <naming-url-patterns>` or the
 callable view object used in the URLconf. For example, given the following
@@ -67,6 +67,33 @@ namespaces into URLs on specific application instances, according to the
 The ``urlconf`` argument is the URLconf module containing the URL patterns to
 use for reversing. By default, the root URLconf for the current thread is used.
 
+The ``query`` keyword argument specifies parameters to be added to the returned
+URL. It can accept an instance of :class:`~django.http.QueryDict` (such as
+``request.GET``) or any value compatible with :func:`urllib.parse.urlencode`.
+The encoded query string is appended to the resolved URL, prefixed by a ``?``.
+
+The ``fragment`` keyword argument specifies a fragment identifier to be
+appended to the returned URL (that is, after the path and query string,
+preceded by a ``#``).
+
+For example:
+
+.. code-block:: pycon
+
+   >>> from django.urls import reverse
+   >>> reverse("admin:index", query={"q": "biscuits", "page": 2}, fragment="results")
+   '/admin/?q=biscuits&page=2#results'
+   >>> reverse("admin:index", query=[("color", "blue"), ("color", 1), ("none", None)])
+   '/admin/?color=blue&color=1&none=None'
+   >>> reverse("admin:index", query={"has empty spaces": "also has empty spaces!"})
+   '/admin/?has+empty+spaces=also+has+empty+spaces%21'
+   >>> reverse("admin:index", fragment="no encoding is done")
+   '/admin/#no encoding is done'
+
+.. versionchanged:: 5.2
+
+    The ``query`` and ``fragment`` arguments were added.
+
 .. note::
 
     The string returned by ``reverse()`` is already

docs/releases/5.2.txt

@@ -370,7 +370,9 @@ Tests
 URLs
 ~~~~
 
-* ...
+* :func:`~django.urls.reverse` now accepts ``query`` and ``fragment`` keyword
+  arguments, allowing the addition of a query string and/or fragment identifier
+  in the generated URL, respectively.
 
 Utilities
 ~~~~~~~~~

tests/urlpatterns_reverse/tests.py

@@ -11,7 +11,12 @@ from admin_scripts.tests import AdminScriptTestCase
 from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
-from django.http import HttpRequest, HttpResponsePermanentRedirect, HttpResponseRedirect
+from django.http import (
+    HttpRequest,
+    HttpResponsePermanentRedirect,
+    HttpResponseRedirect,
+    QueryDict,
+)
 from django.shortcuts import redirect
 from django.test import RequestFactory, SimpleTestCase, TestCase, override_settings
 from django.test.utils import override_script_prefix
@@ -531,6 +536,81 @@ class URLPatternReverse(SimpleTestCase):
         with self.assertRaises(NoReverseMatch):
             reverse(views.view_func_from_cbv)
 
+    def test_reverse_with_query(self):
+        self.assertEqual(
+            reverse("test", query={"hello": "world", "foo": 123}),
+            "/test/1?hello=world&foo=123",
+        )
+
+    def test_reverse_with_query_sequences(self):
+        cases = [
+            [("hello", "world"), ("foo", 123), ("foo", 456)],
+            (("hello", "world"), ("foo", 123), ("foo", 456)),
+            {"hello": "world", "foo": (123, 456)},
+        ]
+        for query in cases:
+            with self.subTest(query=query):
+                self.assertEqual(
+                    reverse("test", query=query), "/test/1?hello=world&foo=123&foo=456"
+                )
+
+    def test_reverse_with_fragment(self):
+        self.assertEqual(reverse("test", fragment="tab-1"), "/test/1#tab-1")
+
+    def test_reverse_with_fragment_not_encoded(self):
+        self.assertEqual(
+            reverse("test", fragment="tab 1 is the best!"), "/test/1#tab 1 is the best!"
+        )
+
+    def test_reverse_with_query_and_fragment(self):
+        self.assertEqual(
+            reverse("test", query={"hello": "world", "foo": 123}, fragment="tab-1"),
+            "/test/1?hello=world&foo=123#tab-1",
+        )
+
+    def test_reverse_with_empty_fragment(self):
+        self.assertEqual(reverse("test", fragment=None), "/test/1")
+        self.assertEqual(reverse("test", fragment=""), "/test/1#")
+
+    def test_reverse_with_invalid_fragment(self):
+        cases = [0, False, {}, [], set(), ()]
+        for fragment in cases:
+            with self.subTest(fragment=fragment):
+                with self.assertRaises(TypeError):
+                    reverse("test", fragment=fragment)
+
+    def test_reverse_with_empty_query(self):
+        cases = [None, "", {}, [], set(), (), QueryDict()]
+        for query in cases:
+            with self.subTest(query=query):
+                self.assertEqual(reverse("test", query=query), "/test/1")
+
+    def test_reverse_with_invalid_query(self):
+        cases = [0, False, [1, 3, 5], {1, 2, 3}]
+        for query in cases:
+            with self.subTest(query=query):
+                with self.assertRaises(TypeError):
+                    print(reverse("test", query=query))
+
+    def test_reverse_encodes_query_string(self):
+        self.assertEqual(
+            reverse(
+                "test",
+                query={
+                    "hello world": "django project",
+                    "foo": [123, 456],
+                    "@invalid": ["?", "!", "a b"],
+                },
+            ),
+            "/test/1?hello+world=django+project&foo=123&foo=456"
+            "&%40invalid=%3F&%40invalid=%21&%40invalid=a+b",
+        )
+
+    def test_reverse_with_query_from_querydict(self):
+        query_string = "a=1&b=2&b=3&c=4"
+        query_dict = QueryDict(query_string)
+        self.assertEqual(reverse("test", query=query_dict), f"/test/1?{query_string}")
+
 
 class ResolverTests(SimpleTestCase):
     def test_resolver_repr(self):