Adap 821/unit tests infer wrong datatype for None values in fixtures

.changes/unreleased/Fixes-20240625-170324.yaml

@@ -0,0 +1,7 @@
+kind: Fixes
+body: 'Handle unit test fixtures where typing goes wrong from first value in column
+  being Null. '
+time: 2024-06-25T17:03:24.73937-07:00
+custom:
+  Author: versusfacit
+  Issue: "821"

dbt/include/redshift/macros/adapters/unit_testing.sql

@@ -0,0 +1,11 @@
+{%- macro redshift__validate_fixture_rows(rows, row_number) -%}
+  {%- if rows is not none and rows|length > 0 -%}
+    {%- set row = rows[0] -%}
+    {%- for key, value in row.items() -%}
+      {%- if value is none -%}
+          {%- set fixture_name = "expected output" if model.resource_type == 'unit_test' else ("'" ~ model.name ~ "'") -%}
+          {{ exceptions.raise_compiler_error("Unit test fixture " ~ fixture_name ~ " in " ~ model.name ~ " does not have any row free of null values, which may cause type mismatch errors during unit test execution.") }}
+      {%- endif -%}
+    {%- endfor -%}
+  {%- endif -%}
+{%- endmacro -%}

dev-requirements.txt

@@ -1,5 +1,5 @@
 # install latest changes in dbt-core + dbt-postgres
-git+https://github.com/dbt-labs/dbt-adapters.git
+git+https://github.com/dbt-labs/dbt-adapters.git@ADAP-821/support_for_redshift_821
 git+https://github.com/dbt-labs/dbt-adapters.git#subdirectory=dbt-tests-adapter
 git+https://github.com/dbt-labs/dbt-common.git
 git+https://github.com/dbt-labs/dbt-core.git#subdirectory=core

tests/functional/adapter/unit_testing/fixtures.py

@@ -0,0 +1,73 @@
+model_none_value_base = """
+{{ config(materialized="table") }}
+
+select 1 as id, 'a' as col1
+"""
+
+model_none_value_model = """
+{{config(materialized="table")}}
+
+select * from {{ ref('none_value_base') }}
+"""
+
+
+test_none_column_value_doesnt_throw_error_csv = """
+unit_tests:
+  - name: test_simple
+
+    model: none_value_model
+    given:
+      - input: ref('none_value_base')
+        format: csv
+        rows: |
+          id,col1
+          ,d
+          ,e
+          6,f
+
+    expect:
+        format: csv
+        rows: |
+          id,col1
+          ,d
+          ,e
+          6,f
+"""
+
+test_none_column_value_doesnt_throw_error_dct = """
+unit_tests:
+  - name: test_simple
+
+    model: none_value_model
+    given:
+      - input: ref('none_value_base')
+        rows:
+          - { "id":  , "col1": "d"}
+          - { "id":  , "col1": "e"}
+          - { "id": 6, "col1": "f"}
+
+    expect:
+      rows:
+        - {id:  , "col1": "d"}
+        - {id:  , "col1": "e"}
+        - {id: 6, "col1": "f"}
+"""
+
+test_none_column_value_will_throw_error = """
+unit_tests:
+  - name: test_simple
+
+    model: none_value_model
+    given:
+      - input: ref('none_value_base')
+        rows:
+          - { "id":  , "col1": "d"}
+          - { "id":  , "col1": "e"}
+          - { "id": 6, "col1": }
+
+    expect:
+      rows:
+        - {id:  , "col1": "d"}
+        - {id:  , "col1": "e"}
+        - {id: 6, "col1": }
+"""

tests/functional/adapter/unit_testing/test_unit_testing.py

@@ -1,7 +1,21 @@
 import pytest
+
+from dbt.artifacts.schemas.results import RunStatus
+from dbt.tests.fixtures.project import write_project_files
+from dbt.tests.util import run_dbt
+
 from dbt.tests.adapter.unit_testing.test_types import BaseUnitTestingTypes
 from dbt.tests.adapter.unit_testing.test_case_insensitivity import BaseUnitTestCaseInsensivity
 from dbt.tests.adapter.unit_testing.test_invalid_input import BaseUnitTestInvalidInput
+from tests.functional.adapter.unit_testing.fixtures import (
+    model_none_value_base,
+    model_none_value_model,
+    test_none_column_value_doesnt_throw_error_csv,
+    test_none_column_value_doesnt_throw_error_dct,
+    test_none_column_value_will_throw_error,
+)
+
+from dbt_common.exceptions import CompilationError
 
 
 class TestRedshiftUnitTestingTypes(BaseUnitTestingTypes):
@@ -34,6 +48,56 @@ def data_types(self):
         ]
 
 
+class RedshiftUnitTestingNone:
+    def test_nones_handled_dict(self, project):
+        run_dbt(["build"])
+
+
+class TestRedshiftUnitTestCsvNone(RedshiftUnitTestingNone):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "none_value_base.sql": model_none_value_base,
+            "none_value_model.sql": model_none_value_model,
+            "__properties.yml": test_none_column_value_doesnt_throw_error_csv,
+        }
+
+
+class TestRedshiftUnitTestDictNone(RedshiftUnitTestingNone):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "none_value_base.sql": model_none_value_base,
+            "none_value_model.sql": model_none_value_model,
+            "__properties.yml": test_none_column_value_doesnt_throw_error_dct,
+        }
+
+
+class TestRedshiftUnitTestingTooManyNonesFails:
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "__properties.yml": test_none_column_value_will_throw_error,
+            "none_value_base.sql": model_none_value_base,
+            "none_value_model.sql": model_none_value_model,
+        }
+
+    def test_invalid_input(self, project):
+        """This is a user-facing exception, so we can't pytest.raise(CompilationError)"""
+
+        def _find_first_error(items):
+            return next((item for item in items if item.status == RunStatus.Error), None)
+
+        run_result = run_dbt(["build"], expect_pass=False)
+        first_item = _find_first_error(run_result)
+
+        assert first_item is not None
+        assert (
+            "does not have any row free of null values, which may cause type mismatch errors during unit test execution"
+            in str(first_item.message)
+        )
+
+
 class TestRedshiftUnitTestCaseInsensitivity(BaseUnitTestCaseInsensivity):
     pass