Added integration test and cleaned up code

plugins/bigquery/dbt/adapters/bigquery/impl.py

@@ -596,16 +596,33 @@ def get_table_ref_from_relation(self, conn, relation):
  conn)
 
  def _update_column_dict(self, bq_column_dict, dbt_columns, parent=''):
- # bq_colunmn_dict generated by SchemaField.to_api_repr()
- dotted_column_name = '{}.{}'.format(parent, bq_column_dict['name']) if parent else bq_column_dict['name']
+ """
+ Helper function to recursively traverse the schema of a table in the
+ update_column_descriptions function below.
+
+ bq_column_dict should be a dict as obtained by the to_api_repr()
+ function of a SchemaField object.
+ """
+ if parent:
+ dotted_column_name = '{}.{}'.format(parent, bq_column_dict['name'])
+ else:
+ dotted_column_name = bq_column_dict['name']
+
  if dotted_column_name in dbt_columns:
  column_config = dbt_columns[dotted_column_name]
  bq_column_dict['description'] = column_config.get('description')
+
  new_fields = []
  for child_col_dict in bq_column_dict.get('fields', list()):
- new_child_column_dict = self._update_column_dict(child_col_dict, dbt_columns, parent=dotted_column_name)
+ new_child_column_dict = self._update_column_dict(
+ child_col_dict,
+ dbt_columns,
+ parent=dotted_column_name
+ )
  new_fields.append(new_child_column_dict)
+
  bq_column_dict['fields'] = new_fields
+
  return bq_column_dict
 
  @available.parse_none
@@ -620,7 +637,10 @@ def update_column_descriptions(self, relation, columns):
  new_schema = []
  for bq_column in table.schema:
  bq_column_dict = bq_column.to_api_repr()
- new_bq_column_dict = self._update_column_dict(bq_column_dict, columns)
+ new_bq_column_dict = self._update_column_dict(
+ bq_column_dict,
+ columns
+ )
  new_schema.append(SchemaField.from_api_repr(new_bq_column_dict))
 
  new_table = google.cloud.bigquery.Table(table_ref, schema=new_schema)

test/integration/060_persist_docs_tests/models-bigquery-nested/schema.yml

@@ -0,0 +1,19 @@
+version: 2
+
+models:
+ - name: table_model_nested
+ columns:
+ - name: level_1
+ description: level_1 column description
+ - name: level_1.level_2
+ description: level_2 column description
+ - name: level_1.level_2.level_3_a
+ description: level_3 column description
+ - name: view_model_nested
+ columns:
+ - name: level_1
+ description: level_1 column description
+ - name: level_1.level_2
+ description: level_2 column description
+ - name: level_1.level_2.level_3_a
+ description: level_3 column description

test/integration/060_persist_docs_tests/models-bigquery-nested/table_model_nested.sql

@@ -0,0 +1,8 @@
+{{ config(materialized='table') }}
+SELECT
+ STRUCT(
+ STRUCT(
+ 1 AS level_3_a,
+ 2 AS level_3_b
+ ) AS level_2
+ ) AS level_1

test/integration/060_persist_docs_tests/models-bigquery-nested/view_model_nested.sql

@@ -0,0 +1,8 @@
+{{ config(materialized='view') }}
+SELECT
+ STRUCT(
+ STRUCT(
+ 1 AS level_3_a,
+ 2 AS level_3_b
+ ) AS level_2
+ ) AS level_1

test/integration/060_persist_docs_tests/test_persist_docs.py

@@ -156,3 +156,70 @@ def test_snowflake_persist_docs(self):
  @use_profile('bigquery')
  def test_bigquery_persist_docs(self):
  self.run_dbt()
+
+
+class TestPersistDocsNested(BasePersistDocsTest):
+ @property
+ def project_config(self):
+ return {
+ 'config-version': 2,
+ 'models': {
+ 'test': {
+ '+persist_docs': {
+ "relation": True,
+ "columns": True,
+ },
+ }
+ }
+ }
+
+ @property
+ def models(self):
+ return 'models-bigquery-nested'
+
+ @use_profile('bigquery')
+ def test_bigquery_persist_docs(self):
+ """
+ run dbt and use the bigquery client from the adapter to check if the
+ colunmn descriptions are persisted on the test model table and view.
+ """
+ import sys
+ self.run_dbt()
+
+ with self.adapter.connection_named('_test'):
+ client = self.adapter.connections.get_thread_connection().handle
+
+ # test for table model
+ table_id = "{}.{}.{}".format(
+ self.default_database,
+ self.unique_schema(),
+ "table_model_nested"
+ )
+ bq_table_schema = client.get_table(table_id).schema
+
+ level_1_field = bq_table_schema[0]
+ assert level_1_field.description == "level_1 column description"
+
+ level_2_field = level_1_field.fields[0]
+ assert level_2_field.description == "level_2 column description"
+
+ level_3_field = level_2_field.fields[0]
+ assert level_3_field.description == "level_3 column description"
+
+ # test for view model
+ view_id = "{}.{}.{}".format(
+ self.default_database,
+ self.unique_schema(),
+ "view_model_nested"
+ )
+ bq_view_schema = client.get_table(view_id).schema
+
+ level_1_field = bq_view_schema[0]
+ assert level_1_field.description == "level_1 column description"
+
+ level_2_field = level_1_field.fields[0]
+ assert level_2_field.description == "level_2 column description"
+
+ level_3_field = level_2_field.fields[0]
+ assert level_3_field.description == "level_3 column description"
+