Improve changelog message and contributors addition

* Running a snapshot with missing required configurations results in uncaught Python exception

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Add a better error messages for undefined macros and when there are less packages installed than specified in `packages.yml`. ([#2999](https://github.com/fishtown-analytics/dbt/issues/2999))
 - Separate `compiled_path` from `build_path`, and print the former alongside node error messages ([#1985](https://github.com/fishtown-analytics/dbt/issues/1985), [#3327](https://github.com/fishtown-analytics/dbt/pull/3327))
 - Fix exception caused when running `dbt debug` with BigQuery connections ([#3314](https://github.com/fishtown-analytics/dbt/issues/3314), [#3351](https://github.com/fishtown-analytics/dbt/pull/3351))
+- Raise better error if snapshot is missing required configurations ([#3381](https://github.com/fishtown-analytics/dbt/issues/3381), [#3385](https://github.com/fishtown-analytics/dbt/pull/3385))
 
 ### Under the hood
 - Added logic for registry requests to raise a timeout error after a response hangs out for 30 seconds and 5 attempts have been made to reach the endpoint ([#3177](https://github.com/fishtown-analytics/dbt/issues/3177), [#3275](https://github.com/fishtown-analytics/dbt/pull/3275))
@@ -28,6 +29,7 @@ Contributors:
 - [@majidaldo](https://github.com/majidaldo) ([#3134](https://github.com/fishtown-analytics/dbt/issues/3134))
 - [@jaypeedevlin](https://github.com/jaypeedevlin) ([#2999](https://github.com/fishtown-analytics/dbt/issues/2999))
 - [@PJGaetan](https://github.com/PJGaetan) ([#3315](https://github.com/fishtown-analytics/dbt/pull/3376))
+- [@jnatkins](https://github.com/jnatkins) ([#3385](https://github.com/fishtown-analytics/dbt/pull/3385))
 
 ## dbt 0.20.0b1 (May 03, 2021)
 

core/dbt/contracts/graph/model_config.py

@@ -457,6 +457,11 @@ class SnapshotConfig(EmptySnapshotConfig):
     @classmethod
     def validate(cls, data):
         super().validate(data)
+        if not data.get('strategy') or not data.get('unique_key') or not \
+                data.get('target_schema'):
+            raise ValidationError(
+                "Snapshots must be configured with a 'strategy', 'unique_key', "
+                "and 'target_schema'.")
         if data.get('strategy') == 'check':
             if not data.get('check_cols'):
                 raise ValidationError(

test/integration/004_simple_snapshot_test/test_simple_snapshot.py

@@ -531,7 +531,7 @@ class TestBadSnapshot(DBTIntegrationTest):
         with self.assertRaises(dbt.exceptions.CompilationException) as exc:
             self.run_dbt(['compile'], expect_pass=False)
 
-        self.assertIn('Compilation Error in model ref_snapshot', str(exc.exception))
+        self.assertIn('Snapshots must be configured with a \'strategy\'', str(exc.exception))
 
 
 class TestCheckCols(TestSimpleSnapshotFiles):

test/unit/test_contracts_graph_parsed.py

@@ -1343,6 +1343,22 @@ def test_invalid_missing_check_cols(basic_check_snapshot_config_dict):
     del wrong_fields['check_cols']
     with pytest.raises(ValidationError, match=r"A snapshot configured with the check strategy"):
         SnapshotConfig.validate(wrong_fields)
+        
+def test_missing_snapshot_configs(basic_check_snapshot_config_dict):
+    wrong_fields = basic_check_snapshot_config_dict
+    del wrong_fields['strategy']
+    with pytest.raises(ValidationError, match=r"Snapshots must be configured with a 'strategy'"):
+        SnapshotConfig.validate(wrong_fields)
+    
+    wrong_fields['strategy'] = 'timestamp'
+    del wrong_fields['unique_key']
+    with pytest.raises(ValidationError, match=r"Snapshots must be configured with a 'strategy'"):
+        SnapshotConfig.validate(wrong_fields)
+        
+    wrong_fields['unique_key'] = 'id'
+    del wrong_fields['target_schema']
+    with pytest.raises(ValidationError, match=r"Snapshots must be configured with a 'strategy'"):
+        SnapshotConfig.validate(wrong_fields)
 
 
 def test_invalid_check_value(basic_check_snapshot_config_dict):