[BREAKING] Only match non-empty string

sanic_routing/patterns.py

@@ -19,6 +19,12 @@ def slug(param: str) -> str:
     return param
 
 
+def nonemptystr(param: str) -> str:
+    if not param:
+        raise ValueError(f"Value {param} is an empty string")
+    return param
+
+
 REGEX_PARAM_NAME = re.compile(r"^<([a-zA-Z_][a-zA-Z0-9_]*)(?::(.*))?>$")
 
 # Predefined path parameter types. The value is a tuple consisteing of a
@@ -30,7 +36,8 @@ def slug(param: str) -> str:
 # The regular expression is generally NOT used. Unless the path is forced
 # to use regex patterns.
 REGEX_TYPES = {
-    "str": (str, re.compile(r"^[^/]+$")),
+    "strorempty": (str, re.compile(r"^[^/]*$")),
+    "str": (nonemptystr, re.compile(r"^[^/]+$")),
     "slug": (slug, re.compile(r"^[a-z0-9]+(?:-[a-z0-9]+)*$")),
     "alpha": (alpha, re.compile(r"^[A-Za-z]+$")),
     "path": (str, re.compile(r"^[^/]?.*?$")),

sanic_routing/router.py

@@ -27,7 +27,7 @@
 from datetime import datetime  # noqa  isort:skip
 from urllib.parse import unquote  # noqa  isort:skip
 from uuid import UUID  # noqa  isort:skip
-from .patterns import parse_date, alpha, slug  # noqa  isort:skip
+from .patterns import parse_date, alpha, slug, nonemptystr  # noqa  isort:skip
 
 
 class BaseRouter(ABC):

tests/test_builtin_param_types.py

@@ -1,5 +1,6 @@
-import pytest
+from unittest.mock import Mock
 
+import pytest
 from sanic_routing import BaseRouter
 from sanic_routing.exceptions import NotFound
 
@@ -131,3 +132,103 @@ def test_correct_slug_v_string(handler):
 
     assert isinstance(retval, str)
     assert retval == "FooBar"
+
+
+@pytest.mark.parametrize(
+    "value,matches",
+    (
+        ("foo", True),
+        ("FooBar", True),
+        ("with123456789", True),
+        ("", False),
+    ),
+)
+def test_nonempty_string(handler, value, matches):
+    def test(path):
+        nonlocal handler
+        router = Router()
+
+        router.add(path, handler)
+        router.finalize()
+
+        if matches:
+            _, handler, params = router.get(f"/{value}", "BASE")
+            retval = handler(**params)
+
+            assert isinstance(retval, str)
+            assert retval == value
+        else:
+            with pytest.raises(NotFound):
+                router.get(f"/{value}", "BASE")
+
+    for path in ("/<foo>", "/<foo:str>"):
+        test(path)
+
+
+@pytest.mark.parametrize(
+    "value",
+    (
+        "foo",
+        "FooBar",
+        "with123456789",
+        "",
+    ),
+)
+def test_empty_string(handler, value):
+    router = Router()
+
+    router.add("/<foo:strorempty>", handler)
+    router.finalize()
+
+    _, handler, params = router.get(f"/{value}", "BASE")
+    retval = handler(**params)
+
+    assert isinstance(retval, str)
+    assert retval == value
+
+
+def test_nonempty_hierarchy():
+    handler1 = Mock()
+    handler2 = Mock()
+    router = Router()
+
+    router.add("/one/<foo>", handler1)
+    router.add("/one/<foo>/<bar>", handler2)
+    router.finalize()
+
+    _, handler, params = router.get("/one/two/", "BASE")
+    expected = {"foo": "two"}
+    handler(**params)
+
+    assert params == expected
+    handler1.assert_called_once_with(**expected)
+    handler2.assert_not_called()
+
+    handler1.reset_mock()
+    handler2.reset_mock()
+
+    _, handler, params = router.get("/one/two/three/", "BASE")
+    expected = {"foo": "two", "bar": "three"}
+    handler(**params)
+
+    assert params == expected
+    handler1.assert_not_called()
+    handler2.assert_called_once_with(**expected)
+
+
+def test_empty_hierarchy():
+    handler1 = Mock()
+    handler2 = Mock()
+    router = Router()
+
+    router.add("/one/<foo>", handler1)
+    router.add("/one/<foo>/<bar:strorempty>", handler2)
+    router.finalize()
+
+    _, handler, params = router.get("/one/two/", "BASE")
+    expected = {"foo": "two", "bar": ""}
+    handler(**params)
+
+    assert params == expected
+    handler1.assert_not_called()
+    handler2.assert_called_once_with(**expected)