Include null checks in utils test base (#7672)

* Include null checks in utils test base

* Add tests for the schema test

* Add tests for this macro

---------

Co-authored-by: Mila Page <[email protected]>

.changes/unreleased/Under the Hood-20230521-125720.yaml

@@ -0,0 +1,6 @@
+kind: Under the Hood
+body: Include null checks in utils test base
+time: 2023-05-21T12:57:20.659726+02:00
+custom:
+  Author: sdebruyn
+  Issue: "7670"

tests/adapter/dbt/tests/adapter/utils/base_utils.py

@@ -1,10 +1,17 @@
 import pytest
 from dbt.tests.util import run_dbt
 
+macros__equals_sql = """
+{% macro equals(actual, expected) %}
+{# -- actual is not distinct from expected #}
+(({{ actual }} = {{ expected }}) or ({{ actual }} is null and {{ expected }} is null))
+{% endmacro %}
+"""
+
 macros__test_assert_equal_sql = """
 {% test assert_equal(model, actual, expected) %}
-select * from {{ model }} where {{ actual }} != {{ expected }}
-
+select * from {{ model }}
+where not {{ equals(actual, expected) }}
 {% endtest %}
 """
 
@@ -13,7 +20,10 @@ class BaseUtils:
     # setup
     @pytest.fixture(scope="class")
     def macros(self):
-        return {"test_assert_equal.sql": macros__test_assert_equal_sql}
+        return {
+            "equals.sql": macros__equals_sql,
+            "test_assert_equal.sql": macros__test_assert_equal_sql,
+        }
 
     # make it possible to dynamically update the macro call with a namespace
     # (e.g.) 'dateadd', 'dbt.dateadd', 'dbt_utils.dateadd'

tests/adapter/dbt/tests/adapter/utils/fixture_null_compare.py

@@ -0,0 +1,34 @@
+MODELS__TEST_MIXED_NULL_COMPARE_SQL = """
+select
+    1 as actual,
+    null as expected
+"""
+
+
+MODELS__TEST_MIXED_NULL_COMPARE_YML = """
+version: 2
+models:
+  - name: test_null_compare
+    tests:
+      - assert_equal:
+          actual: actual
+          expected: expected
+"""
+
+
+MODELS__TEST_NULL_COMPARE_SQL = """
+select
+    null as actual,
+    null as expected
+"""
+
+
+MODELS__TEST_NULL_COMPARE_YML = """
+version: 2
+models:
+  - name: test_null_compare
+    tests:
+      - assert_equal:
+          actual: actual
+          expected: expected
+"""

tests/adapter/dbt/tests/adapter/utils/test_null_compare.py

@@ -0,0 +1,40 @@
+import pytest
+
+from dbt.tests.adapter.utils.base_utils import BaseUtils
+from dbt.tests.adapter.utils.fixture_null_compare import (
+    MODELS__TEST_MIXED_NULL_COMPARE_SQL,
+    MODELS__TEST_MIXED_NULL_COMPARE_YML,
+    MODELS__TEST_NULL_COMPARE_SQL,
+    MODELS__TEST_NULL_COMPARE_YML,
+)
+from dbt.tests.util import run_dbt
+
+
+class BaseMixedNullCompare(BaseUtils):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "test_mixed_null_compare.yml": MODELS__TEST_MIXED_NULL_COMPARE_SQL,
+            "test_mixed_null_compare.sql": MODELS__TEST_MIXED_NULL_COMPARE_YML,
+        }
+
+    def test_build_assert_equal(self, project):
+        run_dbt()
+        run_dbt(["test"], expect_pass=False)
+
+
+class BaseNullCompare(BaseUtils):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "test_null_compare.yml": MODELS__TEST_NULL_COMPARE_YML,
+            "test_null_compare.sql": MODELS__TEST_NULL_COMPARE_SQL,
+        }
+
+
+class TestMixedNullCompare(BaseNullCompare):
+    pass
+
+
+class TestNullCompare(BaseNullCompare):
+    pass