Add test to ensure a bad incremental strategy results in an error on run

Right now, this test will fail. That is because the fix will be in the
next commit. Presently if an incremental model is being built for the
first time (because the relation in the data warehouse doesn't exist)
or if the incremental model is being run as a full refresh, then validation
that the incremental strategy _doesn't happen_. Technically for _most_
incremental strategies, this is "okay" because the incremental strategy
isn't used when creating the relation for the first time or during full
refresh. The exception is the microbatch strategy, which is part of the
problem. The other part of the problem is that this leads to an experience
where if you write up an incremental model (with an invalid strategy) and
then run it to ensure it works, you won't know anything is wrong until it
is run for the second time.

dbt-tests-adapter/dbt/tests/adapter/basic/files.py

@@ -186,6 +186,10 @@
   {{ config(materialized="incremental") }}
 """
 
+config_materialized_incremental_invalid_strategy = """
+  {{ config(materialized="incremental", incremental_strategy="bad_strategy") }}
+"""
+
 config_materialized_var = """
   {{ config(materialized=var("materialized_var", "table"))}}
 """
@@ -217,3 +221,4 @@
 ephemeral_view_sql = config_materialized_view + model_ephemeral
 ephemeral_table_sql = config_materialized_table + model_ephemeral
 incremental_sql = config_materialized_incremental + model_incremental
+incremental_invalid_strategy_sql = config_materialized_incremental_invalid_strategy + model_incremental

dbt-tests-adapter/dbt/tests/adapter/basic/test_incremental.py

@@ -85,10 +85,35 @@ def test_incremental_not_schema_change(self, project):
 
         assert run_result == RunStatus.Success
 
+class BaseIncrementalBadStrategy:
+    @pytest.fixture(scope="class")
+    def project_config_update(self):
+        return {"name": "incremental"}
+
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {"incremental.sql": files.incremental_invalid_strategy_sql,}
+
+    @pytest.fixture(scope="class")
+    def seeds(self):
+        return {"base.csv": files.seeds_base_csv, "added.csv": files.seeds_added_csv}
+
+    def test_incremental_invalid_strategy(self, project):
+        # seed command
+        results = run_dbt(["seed"])
+        assert len(results) == 2
+
+        # try to run the incremental model, it should fail on the first attempt
+        results = run_dbt(["run"], expect_pass=False)
+
 
 class Testincremental(BaseIncremental):
     pass
 
 
 class TestBaseIncrementalNotSchemaChange(BaseIncrementalNotSchemaChange):
     pass
+
+
+class TestBaseIncrementalBadStrategy(BaseIncrementalBadStrategy):
+    pass