Remove default factory call results from the JSON schema (#6126)

pydantic · Jun 14, 2023 · b618dbd · b618dbd
1 parent 23db871
commit b618dbd
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Showing 4 changed files with 24 additions and 13 deletions.
diff --git a/docs/usage/dataclasses.md b/docs/usage/dataclasses.md
@@ -64,12 +64,7 @@ print(TypeAdapter(User).json_schema())
             'description': 'do not lie!',
             'title': 'The age of the user',
         },
-        'friends': {
-            'default': [0],
-            'items': {'type': 'integer'},
-            'title': 'Friends',
-            'type': 'array',
-        },
+        'friends': {'items': {'type': 'integer'}, 'title': 'Friends', 'type': 'array'},
         'height': {
             'anyOf': [
                 {'maximum': 300, 'minimum': 50, 'type': 'integer'},

diff --git a/pydantic/json_schema.py b/pydantic/json_schema.py
@@ -734,12 +734,17 @@ def function_wrap_schema(self, schema: core_schema.WrapValidatorFunctionSchema)
     def default_schema(self, schema: core_schema.WithDefaultSchema) -> JsonSchemaValue:
         json_schema = self.generate_inner(schema['schema'])
 
-        if 'default' in schema:
-            default = schema['default']
-        elif 'default_factory' in schema:
-            default = schema['default_factory']()
-        else:  # pragma: no cover
-            raise ValueError('`schema` has neither default nor default_factory')
+        if 'default' not in schema:
+            return json_schema
+        default = schema['default']
+        # Note: if you want to include the value returned by the default_factory,
+        # override this method and replace the code above with:
+        # if 'default' in schema:
+        #     default = schema['default']
+        # elif 'default_factory' in schema:
+        #     default = schema['default_factory']()
+        # else:
+        #     return json_schema
 
         try:
             encoded_default = self.encode_default(default)

diff --git a/tests/test_dataclasses.py b/tests/test_dataclasses.py
@@ -566,7 +566,6 @@ class User:
             },
             'aliases': {
                 'additionalProperties': {'type': 'string'},
-                'default': {'John': 'Joey'},
                 'title': 'Aliases',
                 'type': 'object',
             },

diff --git a/tests/test_json_schema.py b/tests/test_json_schema.py
@@ -4621,3 +4621,15 @@ class Model(BaseModel):
         'examples': b'{"foo":{"name":"John","age":28}}',
         'title': 'ModelTitle',
     }
+
+
+def test_inclusion_of_defaults():
+    class Model(BaseModel):
+        x: int = 1
+        y: int = Field(default_factory=lambda: 2)
+
+    assert Model.model_json_schema() == {
+        'properties': {'x': {'default': 1, 'title': 'X', 'type': 'integer'}, 'y': {'title': 'Y', 'type': 'integer'}},
+        'title': 'Model',
+        'type': 'object',
+    }