Type asset_expression in the REST API so the UI does not cast through unknown

airflow-core/src/airflow/api_fastapi/core_api/datamodels/common.py

@@ -23,12 +23,133 @@
 from __future__ import annotations
 
 import enum
+import logging
 from typing import Annotated, Any, Generic, Literal, TypeVar, Union
 
-from pydantic import Discriminator, Field, Tag
+from pydantic import BeforeValidator, Discriminator, Field, Tag, TypeAdapter, ValidationError
 
 from airflow.api_fastapi.core_api.base import BaseModel, StrictBaseModel
 
+log = logging.getLogger(__name__)
+
+# Asset Scheduling Expression Data Models
+#
+# These mirror the JSON produced by ``BaseAsset.as_expression()`` (see
+# ``airflow.serialization.definitions.assets``), which is stored verbatim in
+# ``DagModel.asset_expression``. Declaring them gives the REST API -- and the
+# TypeScript client generated from its OpenAPI spec -- a real type instead of an
+# opaque ``dict``. The shape is a recursive boolean tree whose leaves are assets,
+# asset aliases, or asset references.
+
+
+class AssetExpressionAssetInfo(BaseModel):
+    """
+    Body of an ``asset`` leaf node.
+
+    ``id`` is injected by ``DagModelOperation.update_dag_asset_expression`` when the expression is
+    persisted; ``BaseAsset.as_expression()`` itself only emits ``uri``/``name``/``group``. It is left
+    optional so a row persisted before id-enrichment (or migrated from the pre-3.0 dataset format)
+    degrades gracefully instead of failing response validation.
+    """
+
+    uri: str
+    name: str
+    group: str
+    id: int | None = None
+
+
+class AssetExpressionAliasInfo(BaseModel):
+    """Body of an ``alias`` leaf node."""
+
+    name: str
+    group: str
+
+
+class AssetExpressionAsset(BaseModel):
+    """An asset leaf: ``{"asset": {"uri": ..., "name": ..., "group": ...}}``."""
+
+    asset: AssetExpressionAssetInfo
+
+
+class AssetExpressionAlias(BaseModel):
+    """An asset alias leaf: ``{"alias": {"name": ..., "group": ...}}``."""
+
+    alias: AssetExpressionAliasInfo
+
+
+class AssetExpressionRef(BaseModel):
+    """An unresolved asset reference leaf: ``{"asset_ref": {"name": ...}}`` or ``{"asset_ref": {"uri": ...}}``."""
+
+    asset_ref: dict[str, str]
+
+
+class AssetExpressionAny(BaseModel):
+    """An "or" node: ``{"any": [...]}`` -- satisfied when any child is satisfied."""
+
+    any: list[AssetExpression]
+
+
+class AssetExpressionAll(BaseModel):
+    """An "and" node: ``{"all": [...]}`` -- satisfied when all children are satisfied."""
+
+    all: list[AssetExpression]
+
+
+def _asset_expression_discriminator(value: Any) -> str | None:
+    """Select an expression variant by the single key that is present."""
+    keys = ("asset", "alias", "asset_ref", "any", "all")
+    if isinstance(value, dict):
+        present = [key for key in keys if key in value]
+    else:
+        present = [key for key in keys if getattr(value, key, None) is not None]
+    return present[0] if len(present) == 1 else None
+
+
+AssetExpression = Annotated[
+    Union[
+        Annotated[AssetExpressionAsset, Tag("asset")],
+        Annotated[AssetExpressionAlias, Tag("alias")],
+        Annotated[AssetExpressionRef, Tag("asset_ref")],
+        Annotated[AssetExpressionAny, Tag("any")],
+        Annotated[AssetExpressionAll, Tag("all")],
+    ],
+    Discriminator(_asset_expression_discriminator),
+]
+"""A nested asset scheduling expression; see ``BaseAsset.as_expression()``."""
+
+AssetExpressionAny.model_rebuild()
+AssetExpressionAll.model_rebuild()
+
+_asset_expression_adapter: TypeAdapter = TypeAdapter(AssetExpression)
+
+
+def _coerce_unrecognized_expression_to_none(value: Any) -> Any:
+    """
+    Degrade an unrecognized ``asset_expression`` to ``None`` instead of failing response validation.
+
+    ``DagModel.asset_expression`` is stored verbatim from ``BaseAsset.as_expression()`` and is rewritten
+    to the current shape whenever a Dag is parsed (``DagModelOperation.update_dag_asset_expression``). A
+    row written by the pre-3.0 dataset scheduler and not yet re-parsed can still hold a legacy shape --
+    a bare uri string, ``{"any": ["s3://..."]}``, or ``{"alias": "<name>"}`` -- that the typed model does
+    not recognise. Serving such a row as ``None`` reproduces the blank render the UI showed while this
+    field was an untyped ``dict``, rather than turning stored data into an HTTP 500.
+    """
+    if value is None:
+        return None
+    try:
+        _asset_expression_adapter.validate_python(value)
+    except ValidationError:
+        log.warning("Dropping unrecognized asset_expression shape to None: %r", value)
+        return None
+    return value
+
+
+MaybeAssetExpression = Annotated[
+    Union[AssetExpression, None],
+    BeforeValidator(_coerce_unrecognized_expression_to_none),
+]
+"""``AssetExpression | None`` that degrades a legacy/unrecognized stored shape to ``None``."""
+
 # Common Bulk Data Models
 T = TypeVar("T")
 K = TypeVar("K")

airflow-core/src/airflow/api_fastapi/core_api/datamodels/dags.py

@@ -35,6 +35,7 @@
 
 from airflow._shared.module_loading import qualname
 from airflow.api_fastapi.core_api.base import BaseModel, StrictBaseModel, make_partial_model
+from airflow.api_fastapi.core_api.datamodels.common import MaybeAssetExpression
 from airflow.api_fastapi.core_api.datamodels.dag_tags import DagTagResponse
 from airflow.api_fastapi.core_api.datamodels.dag_versions import DagVersionResponse
 from airflow.configuration import conf
@@ -191,7 +192,7 @@ class DAGDetailsResponse(DAGResponse):
 
     catchup: bool
     dag_run_timeout: timedelta | None
-    asset_expression: dict | None
+    asset_expression: MaybeAssetExpression
     doc_md: str | None
     start_date: datetime | None
     end_date: datetime | None

airflow-core/src/airflow/api_fastapi/core_api/datamodels/ui/assets.py

@@ -21,6 +21,7 @@
 from pydantic import Field
 
 from airflow.api_fastapi.core_api.base import BaseModel
+from airflow.api_fastapi.core_api.datamodels.common import MaybeAssetExpression
 
 
 class NextRunAssetEventResponse(BaseModel):
@@ -49,6 +50,6 @@ class NextRunAssetEventResponse(BaseModel):
 class NextRunAssetsResponse(BaseModel):
     """Response for the ``next_run_assets`` endpoint."""
 
-    asset_expression: dict | None = None
+    asset_expression: MaybeAssetExpression = None
     events: list[NextRunAssetEventResponse]
     pending_partition_count: int | None = None

airflow-core/src/airflow/api_fastapi/core_api/datamodels/ui/dags.py

@@ -18,6 +18,7 @@
 from __future__ import annotations
 
 from airflow.api_fastapi.core_api.base import BaseModel
+from airflow.api_fastapi.core_api.datamodels.common import MaybeAssetExpression
 from airflow.api_fastapi.core_api.datamodels.dags import DAGResponse
 from airflow.api_fastapi.core_api.datamodels.hitl import HITLDetail
 from airflow.api_fastapi.core_api.datamodels.ui.dag_runs import DAGRunLightResponse
@@ -26,7 +27,7 @@
 class DAGWithLatestDagRunsResponse(DAGResponse):
     """DAG with latest dag runs response serializer."""
 
-    asset_expression: dict | None
+    asset_expression: MaybeAssetExpression
     latest_dag_runs: list[DAGRunLightResponse]
     pending_actions: list[HITLDetail]
     is_favorite: bool

airflow-core/src/airflow/api_fastapi/core_api/datamodels/ui/partitioned_dag_runs.py

@@ -17,6 +17,7 @@
 from __future__ import annotations
 
 from airflow.api_fastapi.core_api.base import BaseModel
+from airflow.api_fastapi.core_api.datamodels.common import MaybeAssetExpression
 
 
 class PartitionedDagRunResponse(BaseModel):
@@ -37,7 +38,7 @@ class PartitionedDagRunCollectionResponse(BaseModel):
 
     partitioned_dag_runs: list[PartitionedDagRunResponse]
     total: int
-    asset_expressions: dict[str, dict | None] | None = None
+    asset_expressions: dict[str, MaybeAssetExpression] | None = None
 
 
 class PartitionedDagRunAssetResponse(BaseModel):
@@ -75,4 +76,4 @@ class PartitionedDagRunDetailResponse(BaseModel):
     assets: list[PartitionedDagRunAssetResponse]
     total_required: int
     total_received: int
-    asset_expression: dict | None = None
+    asset_expression: MaybeAssetExpression = None

airflow-core/src/airflow/api_fastapi/core_api/openapi/_private_ui.yaml

@@ -1736,6 +1736,123 @@ paths:
                 $ref: '#/components/schemas/HTTPValidationError'
 components:
   schemas:
+    AssetExpressionAlias:
+      properties:
+        alias:
+          $ref: '#/components/schemas/AssetExpressionAliasInfo'
+      type: object
+      required:
+      - alias
+      title: AssetExpressionAlias
+      description: 'An asset alias leaf: ``{"alias": {"name": ..., "group": ...}}``.'
+    AssetExpressionAliasInfo:
+      properties:
+        name:
+          type: string
+          title: Name
+        group:
+          type: string
+          title: Group
+      type: object
+      required:
+      - name
+      - group
+      title: AssetExpressionAliasInfo
+      description: Body of an ``alias`` leaf node.
+    AssetExpressionAll:
+      properties:
+        all:
+          items:
+            oneOf:
+            - $ref: '#/components/schemas/AssetExpressionAsset'
+            - $ref: '#/components/schemas/AssetExpressionAlias'
+            - $ref: '#/components/schemas/AssetExpressionRef'
+            - $ref: '#/components/schemas/AssetExpressionAny'
+            - $ref: '#/components/schemas/AssetExpressionAll'
+          type: array
+          title: All
+      type: object
+      required:
+      - all
+      title: AssetExpressionAll
+      description: 'An "and" node: ``{"all": [...]}`` -- satisfied when all children
+        are satisfied.'
+    AssetExpressionAny:
+      properties:
+        any:
+          items:
+            oneOf:
+            - $ref: '#/components/schemas/AssetExpressionAsset'
+            - $ref: '#/components/schemas/AssetExpressionAlias'
+            - $ref: '#/components/schemas/AssetExpressionRef'
+            - $ref: '#/components/schemas/AssetExpressionAny'
+            - $ref: '#/components/schemas/AssetExpressionAll'
+          type: array
+          title: Any
+      type: object
+      required:
+      - any
+      title: AssetExpressionAny
+      description: 'An "or" node: ``{"any": [...]}`` -- satisfied when any child is
+        satisfied.'
+    AssetExpressionAsset:
+      properties:
+        asset:
+          $ref: '#/components/schemas/AssetExpressionAssetInfo'
+      type: object
+      required:
+      - asset
+      title: AssetExpressionAsset
+      description: 'An asset leaf: ``{"asset": {"uri": ..., "name": ..., "group":
+        ...}}``.'
+    AssetExpressionAssetInfo:
+      properties:
+        uri:
+          type: string
+          title: Uri
+        name:
+          type: string
+          title: Name
+        group:
+          type: string
+          title: Group
+        id:
+          anyOf:
+          - type: integer
+          - type: 'null'
+          title: Id
+      type: object
+      required:
+      - uri
+      - name
+      - group
+      title: AssetExpressionAssetInfo
+      description: 'Body of an ``asset`` leaf node.
+
+
+        ``id`` is injected by ``DagModelOperation.update_dag_asset_expression`` when
+        the expression is
+
+        persisted; ``BaseAsset.as_expression()`` itself only emits ``uri``/``name``/``group``.
+        It is left
+
+        optional so a row persisted before id-enrichment (or migrated from the pre-3.0
+        dataset format)
+
+        degrades gracefully instead of failing response validation.'
+    AssetExpressionRef:
+      properties:
+        asset_ref:
+          additionalProperties:
+            type: string
+          type: object
+          title: Asset Ref
+      type: object
+      required:
+      - asset_ref
+      title: AssetExpressionRef
+      description: 'An unresolved asset reference leaf: ``{"asset_ref": {"name": ...}}``
+        or ``{"asset_ref": {"uri": ...}}``.'
     AuthenticatedMeResponse:
       properties:
         id:
@@ -2295,8 +2412,12 @@ components:
           title: Owners
         asset_expression:
           anyOf:
-          - additionalProperties: true
-            type: object
+          - oneOf:
+            - $ref: '#/components/schemas/AssetExpressionAsset'
+            - $ref: '#/components/schemas/AssetExpressionAlias'
+            - $ref: '#/components/schemas/AssetExpressionRef'
+            - $ref: '#/components/schemas/AssetExpressionAny'
+            - $ref: '#/components/schemas/AssetExpressionAll'
           - type: 'null'
           title: Asset Expression
         latest_dag_runs:
@@ -3239,8 +3360,12 @@ components:
       properties:
         asset_expression:
           anyOf:
-          - additionalProperties: true
-            type: object
+          - oneOf:
+            - $ref: '#/components/schemas/AssetExpressionAsset'
+            - $ref: '#/components/schemas/AssetExpressionAlias'
+            - $ref: '#/components/schemas/AssetExpressionRef'
+            - $ref: '#/components/schemas/AssetExpressionAny'
+            - $ref: '#/components/schemas/AssetExpressionAll'
           - type: 'null'
           title: Asset Expression
         events:
@@ -3400,8 +3525,12 @@ components:
           anyOf:
           - additionalProperties:
               anyOf:
-              - additionalProperties: true
-                type: object
+              - oneOf:
+                - $ref: '#/components/schemas/AssetExpressionAsset'
+                - $ref: '#/components/schemas/AssetExpressionAlias'
+                - $ref: '#/components/schemas/AssetExpressionRef'
+                - $ref: '#/components/schemas/AssetExpressionAny'
+                - $ref: '#/components/schemas/AssetExpressionAll'
               - type: 'null'
             type: object
           - type: 'null'
@@ -3451,8 +3580,12 @@ components:
           title: Total Received
         asset_expression:
           anyOf:
-          - additionalProperties: true
-            type: object
+          - oneOf:
+            - $ref: '#/components/schemas/AssetExpressionAsset'
+            - $ref: '#/components/schemas/AssetExpressionAlias'
+            - $ref: '#/components/schemas/AssetExpressionRef'
+            - $ref: '#/components/schemas/AssetExpressionAny'
+            - $ref: '#/components/schemas/AssetExpressionAll'
           - type: 'null'
           title: Asset Expression
       type: object