Fix const in anyOf/oneOf to generate Literal type (#2864)

Author: koxudaxi

src/datamodel_code_generator/parser/jsonschema.py

@@ -1262,9 +1262,10 @@ def get_data_type(self, obj: JsonSchemaObject) -> DataType:
         if python_type_override:
             return python_type_override
 
+        if "const" in obj.extras:
+            return self.data_type(literals=[obj.extras["const"]])
+
         if obj.type is None:
-            if "const" in obj.extras:
-                return self.data_type_manager.get_data_type_from_value(obj.extras["const"])
             return self.data_type_manager.get_data_type(
                 Types.any,
             )

tests/data/expected/main/jsonschema/all_of_any_of_base_class_ref.py

@@ -4,11 +4,15 @@
 
 from __future__ import annotations
 
+from typing import Literal
+
 from pydantic import BaseModel, Field, confloat
 
 
 class MapState1(BaseModel):
-    map_view_mode: str = Field("MODE_2D", alias="mapViewMode", const=True)
+    map_view_mode: Literal["MODE_2D"] = Field(
+        "MODE_2D", alias="mapViewMode", const=True
+    )
 
 
 class MapState2(BaseModel):
@@ -18,8 +22,10 @@ class MapState2(BaseModel):
     bearing: Bearing | None = None
     pitch: Pitch
     drag_rotate: DragRotate | None = Field(None, alias="dragRotate")
-    map_split_mode: str = Field("SWIPE_COMPARE", alias="mapSplitMode", const=True)
-    is_split: bool = Field(True, alias="isSplit", const=True)
+    map_split_mode: Literal["SWIPE_COMPARE"] = Field(
+        "SWIPE_COMPARE", alias="mapSplitMode", const=True
+    )
+    is_split: Literal[True] = Field(True, alias="isSplit", const=True)
 
 
 class MapState3(BaseModel):

tests/data/expected/main/jsonschema/anyof_const_with_constraints.py

@@ -0,0 +1,12 @@
+# generated by datamodel-codegen:
+#   filename:  anyof_const_with_constraints.json
+
+from __future__ import annotations
+
+from typing import Literal
+
+from pydantic import BaseModel, conint
+
+
+class Model(BaseModel):
+    SomeValue: Literal[500000] | conint(ge=0, le=65534) | None = None

tests/data/expected/main/jsonschema/discriminator_with_external_references_folder/inner_folder/artificial_folder/type_1.py

@@ -10,4 +10,4 @@
 
 
 class Type1(BaseModel):
-    type_: Literal['a'] = Field(..., const=True, title='Type ')
+    type_: Literal['a'] = Field('a', const=True, title='Type ')

tests/data/expected/main/jsonschema/discriminator_with_external_references_folder/inner_folder/schema.py

@@ -15,7 +15,7 @@
 
 
 class Type3(BaseModel):
-    type_: Literal['c'] = Field(..., const=True, title='Type ')
+    type_: Literal['c'] = Field('c', const=True, title='Type ')
 
 
 class Response(BaseModel):

tests/data/expected/main/jsonschema/discriminator_with_external_references_folder/inner_folder/type_2.py

@@ -12,5 +12,5 @@
 
 
 class Type2(BaseModel):
-    type_: Literal['b'] = Field(..., const=True, title='Type ')
+    type_: Literal['b'] = Field('b', const=True, title='Type ')
     ref_type: type_1.Type1 | None = Field(None, description='A referenced type.')

tests/data/expected/main/jsonschema/discriminator_with_external_references_folder/subfolder/type_5.py

@@ -10,4 +10,4 @@
 
 
 class Type5(BaseModel):
-    type_: Literal['e'] = Field(..., const=True, title='Type ')
+    type_: Literal['e'] = Field('e', const=True, title='Type ')

tests/data/expected/main/jsonschema/discriminator_with_external_references_folder/type_4.py

@@ -10,4 +10,4 @@
 
 
 class Type4(BaseModel):
-    type_: Literal['d'] = Field(..., const=True, title='Type ')
+    type_: Literal['d'] = Field('d', const=True, title='Type ')

tests/data/expected/main/jsonschema/oneof_const_mixed_with_ref.py

@@ -4,6 +4,8 @@
 
 from __future__ import annotations
 
+from typing import Literal
+
 from pydantic import BaseModel, Field
 
 
@@ -12,4 +14,4 @@ class SomeType(BaseModel):
 
 
 class MixedUnion(BaseModel):
-    __root__: str | SomeType = Field(..., title='MixedUnion')
+    __root__: Literal['value1'] | SomeType = Field(..., title='MixedUnion')

tests/data/expected/main/jsonschema/oneof_const_with_properties.py

@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from typing import Any
+from typing import Any, Literal
 
 from pydantic import BaseModel, Field
 
@@ -14,4 +14,4 @@ class ConstWithProps1(BaseModel):
 
 
 class ConstWithProps(BaseModel):
-    __root__: ConstWithProps1 | str = Field(..., title='ConstWithProps')
+    __root__: ConstWithProps1 | Literal['value2'] = Field(..., title='ConstWithProps')