"format" supports all types by default

Previously, formats could set applicable types, but in the decorator
the types were defaulted to ("string",), contrary to the behavior of
keywords in general and the "format" keyword class in particular.

Since the tutorial example, unit tests, and the one format
validator all check the instance type before proceeding, it looked
very much like format validator functions were expected to do
their own type checking.

This change aligns the default type applicability of formats with
that of keywords, and updates all implementations, tests, and
examples to rely on the decorator parameter to handle the type check.

CHANGELOG.rst

@@ -1,6 +1,13 @@
 Changelog
 =========
 
+v0.10.4 (in development)
+------------------------
+Bug Fixes:
+
+* "format" applies to all types
+
+
 v0.10.3 (2023-05-21)
 --------------------
 Bug Fixes:

examples/format_validation.py

@@ -6,17 +6,15 @@
 
 
 # register an 'ipv4' format validator
-@format_validator('ipv4')
+@format_validator('ipv4', instance_types=('string',))
 def validate_ipv4(value: str) -> None:
-    if isinstance(value, str):
-        ipaddress.IPv4Address(value)  # raises ValueError for an invalid IPv4 address
+    ipaddress.IPv4Address(value)  # raises ValueError for an invalid IPv4 address
 
 
 # register an 'ipv6' format validator
-@format_validator('ipv6')
+@format_validator('ipv6', instance_types=('string',))
 def validate_ipv6(value: str) -> None:
-    if isinstance(value, str):
-        ipaddress.IPv6Address(value)  # raises ValueError for an invalid IPv6 address
+    ipaddress.IPv6Address(value)  # raises ValueError for an invalid IPv6 address
 
 
 # initialize the catalog, with JSON Schema 2020-12 vocabulary support

jschon/formats.py

@@ -2,8 +2,7 @@
 from jschon.vocabulary.format import format_validator
 
 
-@format_validator('json-pointer')
+@format_validator('json-pointer', instance_types=('string',))
 def validate_json_pointer(value: str) -> None:
-    if isinstance(value, str):
-        if not JSONPointer._json_pointer_re.fullmatch(value):
-            raise ValueError
+    if not JSONPointer._json_pointer_re.fullmatch(value):
+        raise ValueError

jschon/vocabulary/format.py

@@ -19,7 +19,7 @@ def __init__(self, parentschema: JSONSchema, value: str):
         if parentschema.catalog.is_format_enabled(value):
             self.validator, self.validates_types = _format_validators[value]
         else:
-            self.validator = None
+            self.validator, self.validates_types = None, set()
 
     def evaluate(self, instance: JSON, result: Result) -> None:
         result.annotate(self.json.value)
@@ -47,7 +47,9 @@ def evaluate(self, instance: JSON, result: Result) -> None:
 def format_validator(
         format_attr: str,
         *,
-        instance_types: Tuple[str, ...] = ('string',)
+        instance_types: Tuple[str, ...] = (
+            "null", "boolean", "number", "string", "array", "object",
+        )
 ):
     """A decorator for a format validation function.
 

tests/test_formats.py

@@ -15,21 +15,28 @@ def setup_validators(catalog):
         "ipv4",
         "ipv6",
         "json-pointer",
+        "uint8",
     )
     yield
     catalog._enabled_formats.clear()
 
 
-@format_validator('ipv4')
+@format_validator('ipv4', instance_types=('string',))
 def ipv4_validator(value):
-    if isinstance(value, str):
-        ipaddress.IPv4Address(value)
+    ipaddress.IPv4Address(value)
 
 
-@format_validator('ipv6')
+@format_validator('ipv6', instance_types=('string',))
 def ipv6_validator(value):
-    if isinstance(value, str):
-        ipaddress.IPv6Address(value)
+    ipaddress.IPv6Address(value)
+
+
+@format_validator('uint8', instance_types=('number',))
+def uint8_validator(value):
+    if value % 1:
+        raise ValueError(f'{value} is not an integer (uint8)')
+    if value < 0 or value > 255:
+        raise ValueError(f'{value} is out of range for uint8')
 
 
 def evaluate(format_attr, instval, assert_=True):
@@ -88,6 +95,22 @@ def test_jsonpointer_invalid(instval):
         assert result is False
 
 
+@pytest.mark.parametrize('instval', (3, "1", "what"))
+def test_uint8_valid(instval):
+    result = evaluate(
+        "uint8",
+        instval,
+        isinstance(instval, (int, float))
+    )
+    assert result is True
+
+
+@pytest.mark.parametrize('instval', (3.001, -1, 256))
+def test_uint8_invalid(instval):
+    result = evaluate("uint8", instval)
+    assert result is False
+
+
 @given(instval=hs.uuids() | hs.text())
 def test_uuid(instval):
     # we've not registered a "uuid" validator, so the test should always pass