03: Circular Dependencies / Out-of-Order Definitions (The "Topological Sort" Limitation)

[dschwartznyc]

Bug Report

Problem Description:

The generator uses a Directed Acyclic Graph (DAG) to order definitions in _bundle.py. However, the current implementation only includes edges for inheritance (SuperTypes). It ignores Attribute types, leading to out-of-order definitions. Furthermore, Rosetta allows recursive/circular types (A has B, B has A), which a DAG cannot resolve by design. Inheritance-based cycles are particularly fatal as base classes must be defined before children.

Steps to Reproduce:

1. Define two types that refer to each other as attributes.
2. Define a child type that inherits from a parent, while the parent refers to the child.
3. Import the generated classes.

• Attribute Cycle: CircularFailure.rosetta

type CircularA:
    b CircularB (1..1)

type CircularB:
    a CircularA (1..1)

Test Cases:

• JUnit: PythonCircularDependencyTest.testAttributeCircularDependency ([testAttributeCircularDependency](https://github.com/finos/rune-python-generator/blob/main/src/test/java/com/regnosys/rosetta/generator/

• Python: test_inheritance_cycle.py.manifest_fail (test_inheritance_cycle)

• Inheritance Cycle: InheritanceCycle.rosetta

type Parent:
    child Child (0..1)

type Child extends Parent:
    val int (1..1)

Test Cases:

• JUnit: PythonCircularDependencyTest.testInheritanceCircularDependency (testInheritanceCircularDependency)
• Python: test_circular_failure.py.manifest_fail (test_circular_failure)

Expected Result:

Definitions should be correctly ordered or forward-referenced using String type hints to allow successful import of the bundle.

Actual Result:

NameError: name '...Parent' is not defined occurs because the generator emitted Child before Parent.

[plamen-neykov]

Given the follwoing Rune:

namespace rosetta_dsl.test.language.CircularDependency : <"generate Python unit tests from Rosetta.">

type A:
    b B (1..1)

type B:
    a A (0..1)

We need to generate the following bundle:
(NOTE: the commented code is what we generate at the moment and is not to be included in the generation)

# pylint: disable=line-too-long, invalid-name, missing-function-docstring
# pylint: disable=bad-indentation, trailing-whitespace, superfluous-parens
# pylint: disable=wrong-import-position, unused-import, unused-wildcard-import
# pylint: disable=wildcard-import, wrong-import-order, missing-class-docstring
# pylint: disable=missing-module-docstring
from __future__ import annotations
from typing import Annotated, Optional


from pydantic import Field
from rune.runtime.base_data_class import BaseDataClass


# class rosetta_dsl_test_language_CircularDependency_B(BaseDataClass):
#     _FQRTN = 'rosetta_dsl.test.language.CircularDependency.B'
#     a: Optional[Annotated[rosetta_dsl_test_language_CircularDependency_A, rosetta_dsl_test_language_CircularDependency_A.serializer(), rosetta_dsl_test_language_CircularDependency_A.validator()]] = Field(None, description='')


# class rosetta_dsl_test_language_CircularDependency_A(BaseDataClass):
#     _FQRTN = 'rosetta_dsl.test.language.CircularDependency.A'
#     b: Annotated[rosetta_dsl_test_language_CircularDependency_B, rosetta_dsl_test_language_CircularDependency_B.serializer(), rosetta_dsl_test_language_CircularDependency_B.validator()] = Field(..., description='')


class rosetta_dsl_test_language_CircularDependency_B(BaseDataClass):
    _FQRTN = 'rosetta_dsl.test.language.CircularDependency.B'
    a: Optional[rosetta_dsl_test_language_CircularDependency_A] = Field(None, description='')


class rosetta_dsl_test_language_CircularDependency_A(BaseDataClass):
    _FQRTN = 'rosetta_dsl.test.language.CircularDependency.A'
    b: rosetta_dsl_test_language_CircularDependency_B = Field(..., description='')


rosetta_dsl_test_language_CircularDependency_B.__annotations__["a"] = Annotated[Optional[rosetta_dsl_test_language_CircularDependency_A], rosetta_dsl_test_language_CircularDependency_A.serializer(), rosetta_dsl_test_language_CircularDependency_A.validator()]
rosetta_dsl_test_language_CircularDependency_A.__annotations__["b"] = Annotated[rosetta_dsl_test_language_CircularDependency_B, rosetta_dsl_test_language_CircularDependency_B.serializer(), rosetta_dsl_test_language_CircularDependency_B.validator()]

rosetta_dsl_test_language_CircularDependency_B.model_rebuild()
rosetta_dsl_test_language_CircularDependency_A.model_rebuild()

# EOF