[Backport 1.5.latest] support doc blocks on versioned models

.changes/unreleased/Fixes-20231004-144148.yaml

@@ -0,0 +1,6 @@
+kind: Fixes
+body: Support docs blocks on versioned model column descriptions
+time: 2023-10-04T14:41:48.843486-05:00
+custom:
+  Author: emmyoop
+  Issue: "8540"

core/dbt/events/base_types.py

@@ -1,6 +1,7 @@
 from enum import Enum
 import os
 import threading
+from typing import Optional
 from dbt.events import types_pb2
 import sys
 from google.protobuf.json_format import ParseDict, MessageToDict, MessageToJson
@@ -126,7 +127,7 @@ class EventMsg(Protocol):
     data: Message
 
 
-def msg_from_base_event(event: BaseEvent, level: EventLevel = None):
+def msg_from_base_event(event: BaseEvent, level: Optional[EventLevel] = None):
 
     msg_class_name = f"{type(event).__name__}Msg"
     msg_cls = getattr(types_pb2, msg_class_name)

core/dbt/events/eventmgr.py

@@ -186,7 +186,7 @@ def __init__(self) -> None:
         self.callbacks: List[Callable[[EventMsg], None]] = []
         self.invocation_id: str = str(uuid4())
 
-    def fire_event(self, e: BaseEvent, level: EventLevel = None) -> None:
+    def fire_event(self, e: BaseEvent, level: Optional[EventLevel] = None) -> None:
         msg = msg_from_base_event(e, level=level)
 
         if os.environ.get("DBT_TEST_BINARY_SERIALIZATION"):

core/dbt/events/functions.py

@@ -257,7 +257,7 @@ def warn_or_error(event, node=None):
 # an alternative to fire_event which only creates and logs the event value
 # if the condition is met. Does nothing otherwise.
 def fire_event_if(
-    conditional: bool, lazy_e: Callable[[], BaseEvent], level: EventLevel = None
+    conditional: bool, lazy_e: Callable[[], BaseEvent], level: Optional[EventLevel] = None
 ) -> None:
     if conditional:
         fire_event(lazy_e(), level=level)
@@ -267,7 +267,7 @@ def fire_event_if(
 # this is where all the side effects happen branched by event type
 # (i.e. - mutating the event history, printing to stdout, logging
 # to files, etc.)
-def fire_event(e: BaseEvent, level: EventLevel = None) -> None:
+def fire_event(e: BaseEvent, level: Optional[EventLevel] = None) -> None:
     EVENT_MANAGER.fire_event(e, level=level)
 
 

core/dbt/parser/generic_test_builders.py

@@ -264,7 +264,7 @@ def __init__(
         target: Testable,
         package_name: str,
         render_ctx: Dict[str, Any],
-        column_name: str = None,
+        column_name: Optional[str] = None,
         version: Optional[NodeVersion] = None,
     ) -> None:
         test_name, test_args = self.extract_test_args(test, column_name)

core/dbt/parser/manifest.py

@@ -917,10 +917,11 @@ def process_metrics(self, config: RuntimeConfig):
                 continue
             _process_metrics_for_node(self.manifest, current_project, exposure)
 
-    # nodes: node and column descriptions
+    # nodes: node and column descriptions, version columns descriptions
     # sources: source and table descriptions, column descriptions
     # macros: macro argument descriptions
     # exposures: exposure descriptions
+    # metrics: metric descriptions
     def process_docs(self, config: RuntimeConfig):
         for node in self.manifest.nodes.values():
             if node.created_at < self.started_at:

core/dbt/parser/schema_renderer.py

@@ -34,12 +34,18 @@ def _is_norender_key(self, keypath: Keypath) -> bool:
         Return True if it's tests or description - those aren't rendered now
         because they're rendered later in parse_generic_tests or process_docs.
         """
+        # top level descriptions and tests
         if len(keypath) >= 1 and keypath[0] in ("tests", "description"):
             return True
 
+        # columns descriptions and tests
         if len(keypath) == 2 and keypath[1] in ("tests", "description"):
             return True
 
+        # versions
+        if len(keypath) == 5 and keypath[4] == "description":
+            return True
+
         if (
             len(keypath) >= 3
             and keypath[0] == "columns"

core/dbt/parser/schemas.py

@@ -540,7 +540,7 @@ def parse_versioned_tests(self, block: VersionedTestBlock) -> None:
                 for test in block.target.get_tests_for_version(version.v):
                     self.parse_test(block, test, None, version.v)
 
-    def parse_file(self, block: FileBlock, dct: Dict = None) -> None:
+    def parse_file(self, block: FileBlock, dct: Optional[Dict] = None) -> None:
         assert isinstance(block.file, SchemaSourceFile)
 
         # If partially parsing, dct should be from pp_dict, otherwise

tests/functional/docs/test_model_version_docs_blocks.py

@@ -0,0 +1,74 @@
+import pytest
+
+from dbt.tests.util import run_dbt
+
+model_1 = """
+select 1 as id, 'joe' as first_name
+"""
+
+model_versioned = """
+select 1 as id, 'joe' as first_name
+"""
+
+docs_md = """
+{% docs model_description %}
+unversioned model
+{% enddocs %}
+
+{% docs column_id_doc %}
+column id for some thing
+{% enddocs %}
+
+{% docs versioned_model_description %}
+versioned model
+{% enddocs %}
+
+"""
+
+schema_yml = """
+models:
+  - name: model_1
+    description: '{{ doc("model_description") }}'
+    columns:
+        - name: id
+          description: '{{ doc("column_id_doc") }}'
+
+  - name: model_versioned
+    description: '{{ doc("versioned_model_description") }}'
+    latest_version: 1
+    versions:
+      - v: 1
+        config:
+          alias: my_alias
+        columns:
+          - name: id
+            description: '{{ doc("column_id_doc") }}'
+          - name: first_name
+            description: 'plain text'
+      - v: 2
+        columns:
+          - name: other_id
+"""
+
+
+class TestVersionedModelDocsBlock:
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "model_1.sql": model_1,
+            "model_versioned.sql": model_versioned,
+            "schema.yml": schema_yml,
+            "docs.md": docs_md,
+        }
+
+    def test_versioned_doc_ref(self, project):
+        manifest = run_dbt(["parse"])
+        model_1 = manifest.nodes["model.test.model_1"]
+        model_v1 = manifest.nodes["model.test.model_versioned.v1"]
+
+        assert model_1.description == "unversioned model"
+        assert model_v1.description == "versioned model"
+
+        assert model_1.columns["id"].description == "column id for some thing"
+        assert model_v1.columns["id"].description == "column id for some thing"
+        assert model_v1.columns["first_name"].description == "plain text"