fix: Enable users to opt-in to allowing extra fields in Tesseract schemas by setting extra="allow" (#117)

#### Relevant issue or PR
Pydantic models inside e.g. `InputSchema` that have `extra="allow"`
failed with extra fields.

#### Description of changes
Only override with `extra="forbid"` if no `model_config` is given.

#### Testing done
Added a test.

#### License

- [x] By submitting this pull request, I confirm that my contribution is
made under the terms of the [Apache 2.0
license](https://pasteurlabs.github.io/tesseract/LICENSE).
- [x] I sign the Developer Certificate of Origin below by adding my name
and email address to the `Signed-off-by` line.

<details>
<summary><b>Developer Certificate of Origin</b></summary>

```text
Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.


Developer's Certificate of Origin 1.1

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(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
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```

</details>

Signed-off-by: [Niklas Heim] <[niklas.heim@simulation.science]>

---------

Co-authored-by: Dion Häfner <dion.haefner@simulation.science>

Author: nmheim

tesseract_core/runtime/schema_generation.py

@@ -11,6 +11,7 @@
     Any,
     ClassVar,
     Literal,
+    Optional,
     TypeVar,
     Union,
     get_args,
@@ -65,7 +66,7 @@ def apply_function_to_model_tree(
     Schema: type[BaseModel],
     func: Callable[[type, tuple], type],
     model_prefix: str = "",
-    model_kwargs: Any = None,
+    default_model_config: Optional[dict[str, Any]] = None,
 ) -> type[BaseModel]:
     """Apply a function to all leaves of a Pydantic model, recursing into containers + nested models.
 
@@ -87,8 +88,8 @@ class MyModel(BaseModel):
     # Annotation types that should be treated as leaves and not recursed into
     annotated_types_as_leaves = (PydanticArrayAnnotation,)
 
-    if model_kwargs is None:
-        model_kwargs = {}
+    if default_model_config is None:
+        default_model_config = {}
 
     seen_models = set()
 
@@ -134,10 +135,15 @@ def _recurse_over_model_tree(treeobj: Any, path: list[str]) -> Any:
             # We only forbid encountering the same model twice if it is within the same subtree
             seen_models.remove(id(treeobj))
 
+            # Only override model_config if it is not already present
+            # in the pydantic model definition
+            model_config = ConfigDict(**default_model_config)
+            model_config.update(treeobj.model_config)
+
             return create_model(
                 f"{model_prefix}{treeobj.__name__}",
                 **new_fields,
-                **model_kwargs,
+                model_config=(ConfigDict, model_config),
                 __base__=treeobj,
             )
 
@@ -271,13 +277,13 @@ def create_apply_schema(
         InputSchema,
         lambda x, _: x,
         model_prefix="Apply_",
-        model_kwargs={"model_config": (ConfigDict, ConfigDict(extra="forbid"))},
+        default_model_config=dict(extra="forbid"),
     )
     OutputSchema = apply_function_to_model_tree(
         OutputSchema,
         lambda x, _: x,
         model_prefix="Apply_",
-        model_kwargs={"model_config": (ConfigDict, ConfigDict(extra="forbid"))},
+        default_model_config=dict(extra="forbid"),
     )
 
     class ApplyInputSchema(BaseModel):
@@ -325,14 +331,14 @@ def replace_array_with_shapedtype(obj: T, _: Any) -> Union[T, type[ShapeDType]]:
         InputSchema,
         replace_array_with_shapedtype,
         model_prefix="AbstractEval_",
-        model_kwargs={"model_config": (ConfigDict, ConfigDict(extra="forbid"))},
+        default_model_config=dict(extra="forbid"),
     )
 
     GeneratedOutputSchema = apply_function_to_model_tree(
         OutputSchema,
         replace_array_with_shapedtype,
         model_prefix="AbstractEval_",
-        model_kwargs={"model_config": (ConfigDict, ConfigDict(extra="forbid"))},
+        default_model_config=dict(extra="forbid"),
     )
 
     class AbstractInputSchema(BaseModel):
@@ -463,7 +469,7 @@ def _find_shape_from_path(path_patterns: dict, concrete_path: str) -> tuple:
         InputSchema,
         lambda x, _: x,
         model_prefix=f"{ad_flavor.title()}_",
-        model_kwargs={"model_config": (ConfigDict, ConfigDict(extra="forbid"))},
+        default_model_config=dict(extra="forbid"),
     )
 
     def result_validator(

tests/runtime_tests/test_schema_generation.py

@@ -8,11 +8,12 @@
 
 import numpy as np
 import pytest
-from pydantic import BaseModel, ValidationError
+from pydantic import BaseModel, ConfigDict, ValidationError
 
 from tesseract_core.runtime import Array, Differentiable, Float32, Float64, Int64, UInt8
 from tesseract_core.runtime.experimental import LazySequence
 from tesseract_core.runtime.schema_generation import (
+    apply_function_to_model_tree,
     create_abstract_eval_schema,
     create_apply_schema,
     create_autodiff_schema,
@@ -688,3 +689,27 @@ def test_json_schema(endpoint):
     # Test that the JSON schema is valid JSON
     json.dumps(schema_inputs)
     json.dumps(schema_outputs)
+
+
+def test_model_config_extra_forbid():
+    class Child(BaseModel):
+        x: str
+        model_config: ConfigDict = ConfigDict(extra="allow")
+
+    class Parent(BaseModel):
+        child: Child
+
+    ApplyParent = apply_function_to_model_tree(
+        Parent,
+        lambda x, y: x,
+        default_model_config=dict(extra="forbid"),
+    )
+    ApplyChild = ApplyParent.model_fields["child"].annotation
+    assert ApplyChild.model_config["extra"] == "allow"
+    assert ApplyParent.model_config["extra"] == "forbid"
+
+    ApplyParent.model_validate({"child": {"x": "foo"}})
+    ApplyParent.model_validate({"child": {"x": "foo", "extra": 1}})
+
+    with pytest.raises(ValidationError):
+        ApplyParent.model_validate({"child": {"x": "foo"}, "extra": 1})