is_instance JSON support (#278)

* is_instance json support

* add benchmark, remove Option from json_type

* remove defult impl of is_instance

* confirm tuples work too

* test for json string not is_instance

Author: samuelcolvin

generate_self_schema.py

@@ -11,7 +11,7 @@
 from collections.abc import Callable
 from datetime import date, datetime, time, timedelta
 from pathlib import Path
-from typing import TYPE_CHECKING, Any, Dict, ForwardRef, List, Type, Union
+from typing import TYPE_CHECKING, Any, Dict, ForwardRef, List, Set, Type, Union
 
 from typing_extensions import get_args, get_origin, is_typeddict
 
@@ -67,6 +67,8 @@ def get_schema(obj) -> core_schema.CoreSchema:
         return {'type': 'literal', 'expected': expected}
     elif issubclass(origin, List):
         return {'type': 'list', 'items_schema': get_schema(obj.__args__[0])}
+    elif issubclass(origin, Set):
+        return {'type': 'set', 'items_schema': get_schema(obj.__args__[0])}
     elif issubclass(origin, Dict):
         return {
             'type': 'dict',

pydantic_core/core_schema.py

@@ -2,7 +2,7 @@
 
 import sys
 from datetime import date, datetime, time, timedelta
-from typing import Any, Callable, Dict, List, Optional, Type, Union, overload
+from typing import Any, Callable, Dict, List, Optional, Set, Type, Union, overload
 
 if sys.version_info < (3, 11):
     from typing_extensions import NotRequired, Protocol, Required
@@ -278,13 +278,21 @@ def literal_schema(*expected: Any, ref: str | None = None) -> LiteralSchema:
     return dict_not_none(type='literal', expected=expected, ref=ref)
 
 
-class IsInstanceSchema(TypedDict):
-    type: Literal['is-instance']
-    cls: Type[Any]
+# must match input/parse_json.rs::JsonType::try_from
+JsonType = Literal['null', 'bool', 'int', 'float', 'str', 'list', 'dict']
+
+
+class IsInstanceSchema(TypedDict, total=False):
+    type: Required[Literal['is-instance']]
+    cls: Required[Type[Any]]
+    json_types: Set[JsonType]
+    ref: str
 
 
-def is_instance_schema(cls: Type[Any]) -> IsInstanceSchema:
-    return dict_not_none(type='is-instance', cls=cls)
+def is_instance_schema(
+    cls: Type[Any], *, json_types: Set[JsonType] | None = None, ref: str | None = None
+) -> IsInstanceSchema:
+    return dict_not_none(type='is-instance', cls=cls, json_types=json_types, ref=ref)
 
 
 class CallableSchema(TypedDict):

src/errors/location.rs

@@ -50,8 +50,10 @@ impl ToPyObject for LocItem {
     }
 }
 
-impl LocItem {
-    pub fn try_from(value: &PyAny) -> PyResult<Self> {
+impl TryFrom<&PyAny> for LocItem {
+    type Error = PyErr;
+
+    fn try_from(value: &PyAny) -> PyResult<Self> {
         if let Ok(str) = value.extract::<String>() {
             Ok(str.into())
         } else {

src/input/input_abstract.rs

@@ -34,9 +34,7 @@ pub trait Input<'a>: fmt::Debug + ToPyObject {
         None
     }
 
-    fn is_instance(&self, _class: &PyType) -> PyResult<bool> {
-        Ok(false)
-    }
+    fn is_instance(&self, class: &PyType, json_mask: u8) -> PyResult<bool>;
 
     fn callable(&self) -> bool {
         false

src/input/input_json.rs

@@ -1,4 +1,8 @@
+use pyo3::prelude::*;
+use pyo3::types::PyType;
+
 use crate::errors::{ErrorKind, InputValue, LocItem, ValError, ValResult};
+use crate::input::JsonType;
 
 use super::datetime::{
     bytes_as_date, bytes_as_datetime, bytes_as_time, bytes_as_timedelta, float_as_datetime, float_as_duration,
@@ -30,6 +34,23 @@ impl<'a> Input<'a> for JsonInput {
         matches!(self, JsonInput::Null)
     }
 
+    fn is_instance(&self, _class: &PyType, json_mask: u8) -> PyResult<bool> {
+        if json_mask == 0 {
+            Ok(false)
+        } else {
+            let json_type: JsonType = match self {
+                JsonInput::Null => JsonType::Null,
+                JsonInput::Bool(_) => JsonType::Bool,
+                JsonInput::Int(_) => JsonType::Int,
+                JsonInput::Float(_) => JsonType::Float,
+                JsonInput::String(_) => JsonType::String,
+                JsonInput::Array(_) => JsonType::Array,
+                JsonInput::Object(_) => JsonType::Object,
+            };
+            Ok(json_type.matches(json_mask))
+        }
+    }
+
     fn validate_args(&'a self) -> ValResult<'a, GenericArguments<'a>> {
         match self {
             JsonInput::Object(kwargs) => Ok(JsonArgs::new(None, Some(kwargs)).into()),
@@ -284,6 +305,14 @@ impl<'a> Input<'a> for String {
         false
     }
 
+    fn is_instance(&self, _class: &PyType, json_mask: u8) -> PyResult<bool> {
+        if json_mask == 0 {
+            Ok(false)
+        } else {
+            Ok(JsonType::String.matches(json_mask))
+        }
+    }
+
     #[cfg_attr(has_no_coverage, no_coverage)]
     fn validate_args(&'a self) -> ValResult<'a, GenericArguments<'a>> {
         Err(ValError::new(ErrorKind::ArgumentsType, self))

src/input/input_python.rs

@@ -81,7 +81,7 @@ impl<'a> Input<'a> for PyAny {
         self.getattr(name).ok()
     }
 
-    fn is_instance(&self, class: &PyType) -> PyResult<bool> {
+    fn is_instance(&self, class: &PyType, _json_mask: u8) -> PyResult<bool> {
         self.is_instance(class)
     }
 

src/input/mod.rs

@@ -10,7 +10,7 @@ mod shared;
 
 pub use datetime::{EitherDate, EitherDateTime, EitherTime, EitherTimedelta};
 pub use input_abstract::Input;
-pub use parse_json::{JsonInput, JsonObject};
+pub use parse_json::{JsonInput, JsonObject, JsonType};
 pub use return_enums::{
     py_string_str, EitherBytes, EitherString, GenericArguments, GenericCollection, GenericIterator, GenericMapping,
     JsonArgs, PyArgs,

src/input/parse_json.rs

@@ -2,9 +2,50 @@ use std::fmt;
 
 use indexmap::IndexMap;
 use pyo3::prelude::*;
-use pyo3::types::PyDict;
+use pyo3::types::{PyDict, PySet};
 use serde::de::{Deserialize, DeserializeSeed, Error as SerdeError, MapAccess, SeqAccess, Visitor};
 
+use crate::build_tools::py_error;
+
+#[derive(Clone, Debug)]
+pub enum JsonType {
+    Null = 0b10000000,
+    Bool = 0b01000000,
+    Int = 0b00100000,
+    Float = 0b00010000,
+    String = 0b00001000,
+    Array = 0b00000100,
+    Object = 0b00000010,
+}
+
+impl JsonType {
+    pub fn combine(set: &PySet) -> PyResult<u8> {
+        set.iter().map(Self::try_from).try_fold(0u8, |a, b| Ok(a | b? as u8))
+    }
+
+    pub fn matches(&self, mask: u8) -> bool {
+        *self as u8 & mask > 0
+    }
+}
+
+impl TryFrom<&PyAny> for JsonType {
+    type Error = PyErr;
+
+    fn try_from(value: &PyAny) -> PyResult<Self> {
+        let s: &str = value.extract()?;
+        match s {
+            "null" => Ok(Self::Null),
+            "bool" => Ok(Self::Bool),
+            "int" => Ok(Self::Int),
+            "float" => Ok(Self::Float),
+            "str" => Ok(Self::String),
+            "list" => Ok(Self::Array),
+            "dict" => Ok(Self::Object),
+            _ => py_error!("Invalid json type: {}", s),
+        }
+    }
+}
+
 /// similar to serde `Value` but with int and float split
 #[derive(Clone, Debug)]
 pub enum JsonInput {

src/validators/is_instance.rs

@@ -1,17 +1,18 @@
 use pyo3::intern;
 use pyo3::prelude::*;
-use pyo3::types::{PyDict, PyType};
+use pyo3::types::{PyDict, PySet, PyType};
 
 use crate::build_tools::SchemaDict;
 use crate::errors::{ErrorKind, ValError, ValResult};
-use crate::input::Input;
+use crate::input::{Input, JsonType};
 use crate::recursion_guard::RecursionGuard;
 
 use super::{BuildContext, BuildValidator, CombinedValidator, Extra, Validator};
 
 #[derive(Debug, Clone)]
 pub struct IsInstanceValidator {
     class: Py<PyType>,
+    json_types: u8,
     class_repr: String,
     name: String,
 }
@@ -27,8 +28,13 @@ impl BuildValidator for IsInstanceValidator {
         let class: &PyType = schema.get_as_req(intern!(schema.py(), "cls"))?;
         let class_repr = class.name()?.to_string();
         let name = format!("{}[{}]", Self::EXPECTED_TYPE, class_repr);
+        let json_types = match schema.get_as::<&PySet>(intern!(schema.py(), "json_types"))? {
+            Some(s) => JsonType::combine(s)?,
+            None => 0,
+        };
         Ok(Self {
             class: class.into(),
+            json_types,
             class_repr,
             name,
         }
@@ -45,7 +51,7 @@ impl Validator for IsInstanceValidator {
         _slots: &'data [CombinedValidator],
         _recursion_guard: &'s mut RecursionGuard,
     ) -> ValResult<'data, PyObject> {
-        match input.is_instance(self.class.as_ref(py))? {
+        match input.is_instance(self.class.as_ref(py), self.json_types)? {
             true => Ok(input.to_object(py)),
             false => Err(ValError::new(
                 ErrorKind::IsInstanceOf {

tests/benchmarks/test_micro_benchmarks.py

@@ -1003,3 +1003,15 @@ def test_generator_rust(benchmark):
     assert sum(v.validate_python(input_value)) == 4950
 
     benchmark(v.validate_python, input_value)
+
+
+@pytest.mark.benchmark(group='isinstance-json')
+def test_isinstance_json(benchmark):
+    validator = SchemaValidator(core_schema.is_instance_schema(str, json_types={'str'}))
+    assert validator.isinstance_json('"foo"') is True
+    assert validator.isinstance_json('123') is False
+
+    @benchmark
+    def t():
+        validator.isinstance_json('"foo"')
+        validator.isinstance_json('123')

tests/validators/test_is_instance.py

@@ -1,6 +1,8 @@
 import pytest
 
-from pydantic_core import SchemaError, SchemaValidator, ValidationError
+from pydantic_core import SchemaError, SchemaValidator, ValidationError, core_schema
+
+from ..conftest import plain_repr
 
 
 class Foo:
@@ -118,3 +120,66 @@ def test_repr():
 def test_is_type(input_val, value):
     v = SchemaValidator({'type': 'is-instance', 'cls': type})
     assert v.isinstance_python(input_val) == value
+
+
+@pytest.mark.parametrize(
+    'input_val,expected',
+    [
+        ('null', False),
+        ('true', True),
+        ('1', False),
+        ('1.1', False),
+        ('"a string"', True),
+        ('["s"]', False),
+        ('{"s": 1}', False),
+    ],
+)
+def test_is_instance_json_string_bool(input_val, expected):
+    v = SchemaValidator(core_schema.is_instance_schema(Foo, json_types={'str', 'bool'}))
+    assert v.isinstance_json(input_val) == expected
+
+
+@pytest.mark.parametrize(
+    'input_val,expected',
+    [
+        ('null', False),
+        ('true', False),
+        ('1', False),
+        ('1.1', False),
+        ('"a string"', False),
+        ('["s"]', True),
+        ('{"s": 1}', False),
+    ],
+)
+def test_is_instance_json_list(input_val, expected):
+    v = SchemaValidator(core_schema.is_instance_schema(Foo, json_types=('list',)))
+    assert v.isinstance_json(input_val) == expected
+
+
+def test_is_instance_dict():
+    v = SchemaValidator(
+        core_schema.dict_schema(
+            keys_schema=core_schema.is_instance_schema(str, json_types={'str'}),
+            values_schema=core_schema.is_instance_schema(int, json_types={'int', 'dict'}),
+        )
+    )
+    assert v.isinstance_python({'foo': 1}) is True
+    assert v.isinstance_python({1: 1}) is False
+    assert v.isinstance_json('{"foo": 1}') is True
+    assert v.isinstance_json('{"foo": "1"}') is False
+    assert v.isinstance_json('{"foo": {"a": 1}}') is True
+
+
+def test_is_instance_dict_not_str():
+    v = SchemaValidator(core_schema.dict_schema(keys_schema=core_schema.is_instance_schema(int, json_types={'int'})))
+    assert v.isinstance_python({1: 1}) is True
+    assert v.isinstance_python({'foo': 1}) is False
+    assert v.isinstance_json('{"foo": 1}') is False
+
+
+def test_json_mask():
+    assert 'json_types:128' in plain_repr(SchemaValidator(core_schema.is_instance_schema(str, json_types={'null'})))
+    assert 'json_types:0' in plain_repr(SchemaValidator(core_schema.is_instance_schema(str)))
+    assert 'json_types:0' in plain_repr(SchemaValidator(core_schema.is_instance_schema(str, json_types=set())))
+    v = SchemaValidator(core_schema.is_instance_schema(str, json_types={'list', 'dict'}))
+    assert 'json_types:6' in plain_repr(v)  # 2 + 4