Move the data parts of SourceDefinition to dbt/artifacts

Something interesting here is that we had to override the `freshness`
property. We had to do this because if we didn't we wouldn't get the
functional parts of `FreshnessThreshold`, we'd only get the data parts.

Also of note, the `SourceDefintion` has a lot of `@property` methods that
on other classes would be actual attribute properties of the node. There is
an argument to be made that these should be moved as well, but thats perhaps
a separate discussion.

Finally, we have not (yet) moved `NodeInfoMixin`. It is an open discussion
whether we do or not. It seems primarily functional, as a means to update the
source freshness information. As the artifacts primarily deal with the shape
of the data, not how it should be set, it seems for now that `NodeInfoMixin`
should stay in core / not move to artifacts. This thinking may change though.

Author: QMalcolm

.changes/unreleased/Under the Hood-20240208-120620.yaml

@@ -0,0 +1,6 @@
+kind: Under the Hood
+body: Move data parts of `SourceDefinition` class to dbt/artifacts
+time: 2024-02-08T12:06:20.696709-08:00
+custom:
+  Author: QMalcolm
+  Issue: "9384"

core/dbt/artifacts/resources/__init__.py

@@ -62,6 +62,7 @@
 from dbt.artifacts.resources.v1.source_definition import (
     ExternalPartition,
     ExternalTable,
+    SourceDefinition,
     ParsedSourceMandatory,
     SourceConfig,
 )

core/dbt/artifacts/resources/v1/source_definition.py

@@ -1,7 +1,14 @@
+import time
+
 from dataclasses import dataclass, field
 from dbt.artifacts.resources.base import GraphResource
 from dbt.artifacts.resources.types import NodeType
-from dbt.artifacts.resources.v1.components import HasRelationMetadata
+from dbt.artifacts.resources.v1.components import (
+    ColumnInfo,
+    FreshnessThreshold,
+    HasRelationMetadata,
+    Quoting,
+)
 from dbt_common.contracts.config.base import BaseConfig
 from dbt_common.contracts.config.properties import AdditionalPropertiesAllowed
 from dbt_common.contracts.util import Mergeable, Replaceable
@@ -45,3 +52,21 @@ class ParsedSourceMandatory(GraphResource, HasRelationMetadata):
     loader: str
     identifier: str
     resource_type: Literal[NodeType.Source]
+
+
+@dataclass
+class SourceDefinition(ParsedSourceMandatory):
+    quoting: Quoting = field(default_factory=Quoting)
+    loaded_at_field: Optional[str] = None
+    freshness: Optional[FreshnessThreshold] = None
+    external: Optional[ExternalTable] = None
+    description: str = ""
+    columns: Dict[str, ColumnInfo] = field(default_factory=dict)
+    meta: Dict[str, Any] = field(default_factory=dict)
+    source_meta: Dict[str, Any] = field(default_factory=dict)
+    tags: List[str] = field(default_factory=list)
+    config: SourceConfig = field(default_factory=SourceConfig)
+    patch_path: Optional[str] = None
+    unrendered_config: Dict[str, Any] = field(default_factory=dict)
+    relation_name: Optional[str] = None
+    created_at: float = field(default_factory=lambda: time.time())

core/dbt/contracts/graph/nodes.py

@@ -78,7 +78,6 @@
     DependsOn,
     Docs,
     Exposure as ExposureResource,
-    ExternalTable as ExternalTableResource,
     MacroDependsOn,
     MacroArgument,
     Documentation as DocumentationResource,
@@ -87,12 +86,11 @@
     NodeVersion,
     Group as GroupResource,
     GraphResource,
-    ParsedSourceMandatory as ParsedSourceMandatoryResource,
     Quoting as QuotingResource,
     RefArgs as RefArgsResource,
     SavedQuery as SavedQueryResource,
     SemanticModel as SemanticModelResource,
-    SourceConfig,
+    SourceDefinition as SourceDefinitionResource,
 )
 
 # =====================================================================
@@ -1212,22 +1210,13 @@ def tests(self) -> List[TestDef]:
 
 @dataclass
 class SourceDefinition(
-    NodeInfoMixin, GraphNode[GraphResource], HasRelationMetadata, ParsedSourceMandatoryResource
+    NodeInfoMixin,
+    GraphNode[SourceDefinitionResource],
+    SourceDefinitionResource,
+    HasRelationMetadata,
 ):
-    quoting: QuotingResource = field(default_factory=QuotingResource)
-    loaded_at_field: Optional[str] = None
+    # Overriding the `freshness` property to use the `FreshnessThreshold` instead of the `FreshnessThresholdResource`
     freshness: Optional[FreshnessThreshold] = None
-    external: Optional[ExternalTableResource] = None
-    description: str = ""
-    columns: Dict[str, ColumnInfoResource] = field(default_factory=dict)
-    meta: Dict[str, Any] = field(default_factory=dict)
-    source_meta: Dict[str, Any] = field(default_factory=dict)
-    tags: List[str] = field(default_factory=list)
-    config: SourceConfig = field(default_factory=SourceConfig)
-    patch_path: Optional[str] = None
-    unrendered_config: Dict[str, Any] = field(default_factory=dict)
-    relation_name: Optional[str] = None
-    created_at: float = field(default_factory=lambda: time.time())
 
     def __post_serialize__(self, dct):
         if "_event_status" in dct: