Add coerce_numbers_to_str option in str_schema (#1249)

Author: NeevCohen

python/pydantic_core/core_schema.py

@@ -764,6 +764,7 @@ def str_schema(
     to_upper: bool | None = None,
     regex_engine: Literal['rust-regex', 'python-re'] | None = None,
     strict: bool | None = None,
+    coerce_numbers_to_str: bool | None = None,
     ref: str | None = None,
     metadata: Any = None,
     serialization: SerSchema | None = None,
@@ -793,6 +794,7 @@ def str_schema(
             - `python-re` use the [`re`](https://docs.python.org/3/library/re.html) module,
               which supports all regex features, but may be slower.
         strict: Whether the value should be a string or a value that can be converted to a string
+        coerce_numbers_to_str: Whether to enable coercion of any `Number` type to `str` (not applicable in `strict` mode).
         ref: optional unique identifier of the schema, used to reference the schema in other places
         metadata: Any other information you want to include with the schema, not used by pydantic-core
         serialization: Custom serialization schema
@@ -807,6 +809,7 @@ def str_schema(
         to_upper=to_upper,
         regex_engine=regex_engine,
         strict=strict,
+        coerce_numbers_to_str=coerce_numbers_to_str,
         ref=ref,
         metadata=metadata,
         serialization=serialization,

src/validators/string.rs

@@ -3,7 +3,7 @@ use pyo3::prelude::*;
 use pyo3::types::{PyDict, PyString};
 use regex::Regex;
 
-use crate::build_tools::{is_strict, py_schema_error_type, schema_or_config};
+use crate::build_tools::{is_strict, py_schema_error_type, schema_or_config, schema_or_config_same};
 use crate::errors::{ErrorType, ValError, ValResult};
 use crate::input::Input;
 use crate::tools::SchemaDict;
@@ -184,12 +184,8 @@ impl StrConstrainedValidator {
         let to_upper: bool =
             schema_or_config(schema, config, intern!(py, "to_upper"), intern!(py, "str_to_upper"))?.unwrap_or(false);
 
-        let coerce_numbers_to_str = match config {
-            Some(c) => c
-                .get_item("coerce_numbers_to_str")?
-                .map_or(Ok(false), |any| any.is_truthy())?,
-            None => false,
-        };
+        let coerce_numbers_to_str: bool =
+            schema_or_config_same(schema, config, intern!(py, "coerce_numbers_to_str"))?.unwrap_or(false);
 
         Ok(Self {
             strict: is_strict(schema, config)?,

tests/validators/test_string.py

@@ -367,3 +367,34 @@ def test_backtracking_regex_python(mode) -> None:
     with pytest.raises(ValidationError):
         # not a valid match for the pattern
         v.validate_python('r#"#')
+
+
+@pytest.mark.parametrize('number', (42, 443, 10242))
+def test_coerce_numbers_to_str_schema(number: int):
+    v = SchemaValidator(core_schema.str_schema(coerce_numbers_to_str=True))
+    assert v.validate_python(number) == str(number)
+    assert v.validate_json(str(number)) == str(number)
+
+
+@pytest.mark.parametrize('number', (42, 443, 10242))
+def test_coerce_numbers_to_str_schema_precedence(number: int):
+    config = core_schema.CoreConfig(coerce_numbers_to_str=False)
+    v = SchemaValidator(core_schema.str_schema(coerce_numbers_to_str=True), config=config)
+    assert v.validate_python(number) == str(number)
+    assert v.validate_json(str(number)) == str(number)
+
+    config = core_schema.CoreConfig(coerce_numbers_to_str=True)
+    v = SchemaValidator(core_schema.str_schema(coerce_numbers_to_str=False), config=config)
+    with pytest.raises(ValidationError):
+        v.validate_python(number)
+    with pytest.raises(ValidationError):
+        v.validate_json(str(number))
+
+
+@pytest.mark.parametrize('number', (42, 443, 10242))
+def test_coerce_numbers_to_str_schema_with_strict_mode(number: int):
+    v = SchemaValidator(core_schema.str_schema(coerce_numbers_to_str=True, strict=True))
+    with pytest.raises(ValidationError):
+        v.validate_python(number)
+    with pytest.raises(ValidationError):
+        v.validate_json(str(number))