Array macros (#5823)

* Helper macro to cast from array to string

* Default implementations and tests for array macros

* Trim Trailing Whitespace

* Changelog entry

* Remove dependence upon `cast_array_to_string` macro

* pre-commit fixes

* Remove `cast_array_to_string` macro

* pre-commit fix

* Trivial direct test; array_concat/append test non-triviallly indirectly

* Remove vestigial `lstrip`

.changes/unreleased/Features-20220912-222227.yaml

@@ -0,0 +1,7 @@
+kind: Features
+body: Array macros
+time: 2022-09-12T22:22:27.475515-06:00
+custom:
+  Author: graciegoheen dbeatty10
+  Issue: "5520"
+  PR: "5823"

core/dbt/include/global_project/macros/utils/array_append.sql

@@ -0,0 +1,8 @@
+{% macro array_append(array, new_element) -%}
+  {{ return(adapter.dispatch('array_append', 'dbt')(array, new_element)) }}
+{%- endmacro %}
+
+{# new_element must be the same data type as elements in array to match postgres functionality #}
+{% macro default__array_append(array, new_element) -%}
+    array_append({{ array }}, {{ new_element }})
+{%- endmacro %}

core/dbt/include/global_project/macros/utils/array_concat.sql

@@ -0,0 +1,7 @@
+{% macro array_concat(array_1, array_2) -%}
+  {{ return(adapter.dispatch('array_concat', 'dbt')(array_1, array_2)) }}
+{%- endmacro %}
+
+{% macro default__array_concat(array_1, array_2) -%}
+    array_cat({{ array_1 }}, {{ array_2 }})
+{%- endmacro %}

core/dbt/include/global_project/macros/utils/array_construct.sql

@@ -0,0 +1,12 @@
+{% macro array_construct(inputs=[], data_type=api.Column.translate_type('integer')) -%}
+  {{ return(adapter.dispatch('array_construct', 'dbt')(inputs, data_type)) }}
+{%- endmacro %}
+
+{# all inputs must be the same data type to match postgres functionality #}
+{% macro default__array_construct(inputs, data_type) -%}
+    {% if inputs|length > 0 %}
+    array[ {{ inputs|join(' , ') }} ]
+    {% else %}
+    array[]::{{data_type}}[]
+    {% endif %}
+{%- endmacro %}

tests/adapter/dbt/tests/adapter/utils/base_array_utils.py

@@ -0,0 +1,22 @@
+from dbt.tests.adapter.utils.base_utils import BaseUtils
+from dbt.tests.util import run_dbt, check_relations_equal, get_relation_columns
+
+
+class BaseArrayUtils(BaseUtils):
+    def assert_columns_equal(self, project, expected_cols, actual_cols):
+        assert (
+            expected_cols == actual_cols
+        ), f"Type difference detected: {expected_cols} vs. {actual_cols}"
+
+    def test_expected_actual(self, project):
+        run_dbt(["build"])
+
+        # check contents equal
+        check_relations_equal(project.adapter, ["expected", "actual"])
+
+        # check types equal
+        expected_cols = get_relation_columns(project.adapter, "expected")
+        actual_cols = get_relation_columns(project.adapter, "actual")
+        print(f"Expected: {expected_cols}")
+        print(f"Actual: {actual_cols}")
+        self.assert_columns_equal(project, expected_cols, actual_cols)

tests/adapter/dbt/tests/adapter/utils/fixture_array_append.py

@@ -0,0 +1,12 @@
+# array_append
+
+models__array_append_expected_sql = """
+select 1 as id, {{ array_construct([1,2,3,4]) }} as array_col union all
+select 2 as id, {{ array_construct([4]) }} as array_col
+"""
+
+
+models__array_append_actual_sql = """
+select 1 as id, {{ array_append(array_construct([1,2,3]), 4) }} as array_col union all
+select 2 as id, {{ array_append(array_construct([]), 4) }} as array_col
+"""

tests/adapter/dbt/tests/adapter/utils/fixture_array_concat.py

@@ -0,0 +1,14 @@
+# array_concat
+
+models__array_concat_expected_sql = """
+select 1 as id, {{ array_construct([1,2,3,4,5,6]) }} as array_col union all
+select 2 as id, {{ array_construct([2]) }} as array_col union all
+select 3 as id, {{ array_construct([3]) }} as array_col
+"""
+
+
+models__array_concat_actual_sql = """
+select 1 as id, {{ array_concat(array_construct([1,2,3]), array_construct([4,5,6])) }} as array_col union all
+select 2 as id, {{ array_concat(array_construct([]), array_construct([2])) }} as array_col union all
+select 3 as id, {{ array_concat(array_construct([3]), array_construct([])) }} as array_col
+"""

tests/adapter/dbt/tests/adapter/utils/fixture_array_construct.py

@@ -0,0 +1,12 @@
+# array_construct
+
+models__array_construct_expected_sql = """
+select 1 as id, {{ array_construct([1,2,3]) }} as array_col union all
+select 2 as id, {{ array_construct([]) }} as array_col
+"""
+
+
+models__array_construct_actual_sql = """
+select 1 as id, {{ array_construct([1,2,3]) }} as array_col union all
+select 2 as id, {{ array_construct([]) }} as array_col
+"""

tests/adapter/dbt/tests/adapter/utils/test_array_append.py

@@ -0,0 +1,19 @@
+import pytest
+from dbt.tests.adapter.utils.base_array_utils import BaseArrayUtils
+from dbt.tests.adapter.utils.fixture_array_append import (
+    models__array_append_actual_sql,
+    models__array_append_expected_sql,
+)
+
+
+class BaseArrayAppend(BaseArrayUtils):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "actual.sql": models__array_append_actual_sql,
+            "expected.sql": models__array_append_expected_sql,
+        }
+
+
+class TestArrayAppend(BaseArrayAppend):
+    pass

tests/adapter/dbt/tests/adapter/utils/test_array_concat.py

@@ -0,0 +1,19 @@
+import pytest
+from dbt.tests.adapter.utils.base_array_utils import BaseArrayUtils
+from dbt.tests.adapter.utils.fixture_array_concat import (
+    models__array_concat_actual_sql,
+    models__array_concat_expected_sql,
+)
+
+
+class BaseArrayConcat(BaseArrayUtils):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "actual.sql": models__array_concat_actual_sql,
+            "expected.sql": models__array_concat_expected_sql,
+        }
+
+
+class TestArrayConcat(BaseArrayConcat):
+    pass

tests/adapter/dbt/tests/adapter/utils/test_array_construct.py

@@ -0,0 +1,19 @@
+import pytest
+from dbt.tests.adapter.utils.base_array_utils import BaseArrayUtils
+from dbt.tests.adapter.utils.fixture_array_construct import (
+    models__array_construct_actual_sql,
+    models__array_construct_expected_sql,
+)
+
+
+class BaseArrayConstruct(BaseArrayUtils):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "actual.sql": models__array_construct_actual_sql,
+            "expected.sql": models__array_construct_expected_sql,
+        }
+
+
+class TestArrayConstruct(BaseArrayConstruct):
+    pass