feat: add condition property to proposition

src/ga4gh/va_spec/base/core.py

@@ -404,6 +404,12 @@ class ClinicalVariantProposition(_SubjectVariantPropositionBase):
     """A proposition for use in describing the effect of variants in human subjects."""
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
+    condition_field_name: ClassVar[str]
+
+    @property
+    def condition(self) -> Condition | iriReference:
+        """Return the condition associated with the proposition."""
+        return getattr(self, self.condition_field_name)
 
     geneContextQualifier: MappableConcept | iriReference | None = Field(
         default=None,
@@ -450,6 +456,7 @@ class VariantClinicalSignificanceProposition(
     """
 
     _maturity: ClassVar[Maturity] = Maturity.DRAFT
+    condition_field_name: ClassVar[str] = "objectCondition"
 
     model_config = ConfigDict(use_enum_values=True)
 
@@ -474,6 +481,7 @@ class VariantDiagnosticProposition(ClinicalVariantProposition, BaseModelForbidEx
     model_config = ConfigDict(use_enum_values=True)
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
+    condition_field_name: ClassVar[str] = "objectCondition"
 
     type: Literal["VariantDiagnosticProposition"] = Field(
         default="VariantDiagnosticProposition",
@@ -492,6 +500,7 @@ class VariantOncogenicityProposition(ClinicalVariantProposition, BaseModelForbid
     """A proposition describing the role of a variant in causing a tumor type."""
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
+    condition_field_name: ClassVar[str] = "objectTumorType"
 
     type: Literal["VariantOncogenicityProposition"] = Field(
         default="VariantOncogenicityProposition",
@@ -510,6 +519,7 @@ class VariantPathogenicityProposition(ClinicalVariantProposition, BaseModelForbi
     """A proposition describing the role of a variant in causing a heritable condition."""
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
+    condition_field_name: ClassVar[str] = "objectCondition"
 
     type: Literal["VariantPathogenicityProposition"] = Field(
         default="VariantPathogenicityProposition",
@@ -538,6 +548,7 @@ class VariantPrognosticProposition(ClinicalVariantProposition, BaseModelForbidEx
     model_config = ConfigDict(use_enum_values=True)
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
+    condition_field_name: ClassVar[str] = "objectCondition"
 
     type: Literal["VariantPrognosticProposition"] = Field(
         default="VariantPrognosticProposition",
@@ -562,6 +573,7 @@ class VariantTherapeuticResponseProposition(
     model_config = ConfigDict(use_enum_values=True)
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
+    condition_field_name: ClassVar[str] = "conditionQualifier"
 
     type: Literal["VariantTherapeuticResponseProposition"] = Field(
         default="VariantTherapeuticResponseProposition",

tests/validation/test_va_spec_models.py

@@ -27,6 +27,12 @@
     Statement,
     StudyGroup,
     StudyResult,
+    VariantClinicalSignificanceProposition,
+    VariantDiagnosticProposition,
+    VariantOncogenicityProposition,
+    VariantPathogenicityProposition,
+    VariantPrognosticProposition,
+    VariantTherapeuticResponseProposition,
 )
 from ga4gh.va_spec.base.domain_entities import ConditionSet
 from ga4gh.va_spec.ccv_2022.models import (
@@ -57,6 +63,54 @@ def caf():
     )
 
 
+@pytest.mark.parametrize(
+    ("proposition_class", "condition_field_name", "predicate"),
+    [
+        (
+            VariantClinicalSignificanceProposition,
+            "objectCondition",
+            "hasClinicalSignificanceFor",
+        ),
+        (
+            VariantDiagnosticProposition,
+            "objectCondition",
+            "isDiagnosticInclusionCriterionFor",
+        ),
+        (VariantOncogenicityProposition, "objectTumorType", "isOncogenicFor"),
+        (VariantPathogenicityProposition, "objectCondition", "isCausalFor"),
+        (
+            VariantPrognosticProposition,
+            "objectCondition",
+            "associatedWithBetterOutcomeFor",
+        ),
+        (
+            VariantTherapeuticResponseProposition,
+            "conditionQualifier",
+            "predictsSensitivityTo",
+        ),
+    ],
+)
+def test_proposition_condition_helpers(
+    proposition_class, condition_field_name, predicate
+):
+    """Test condition access without knowing the proposition field name."""
+    initial_condition = iriReference(root="conditions.json#/1")
+    proposition_data = {
+        "subjectVariant": "alleles.json#/1",
+        "predicate": predicate,
+        condition_field_name: initial_condition,
+    }
+    if proposition_class is VariantTherapeuticResponseProposition:
+        proposition_data["objectTherapeutic"] = "therapeutics.json#/1"
+
+    proposition = proposition_class(**proposition_data)
+
+    assert proposition.condition == initial_condition
+    assert proposition.condition == getattr(proposition, condition_field_name)
+    assert "condition" not in proposition.model_dump()
+    assert "condition" not in proposition_class.model_json_schema()["properties"]
+
+
 def test_condition_set():
     """Ensure ConditionSet model works as expected"""
     condition_set_dict = {