DynamoDB: scan() should respect the Projection-attribute of GSI/LSI's (#5960)

moto/dynamodb/models/table.py

@@ -843,6 +843,12 @@ class Table(CloudFormationModel):
             if passes_all_conditions:
                 results.append(item)
 
+        results = copy.deepcopy(results)
+        if index_name:
+            index = self.get_index(index_name)
+            for result in results:
+                index.project(result)
+
         results, last_evaluated_key = self._trim_results(
             results, limit, exclusive_start_key, scanned_index=index_name
         )

tests/test_dynamodb/test_dynamodb.py

@@ -4708,6 +4708,17 @@ def test_gsi_projection_type_include():
         }
     )
 
+    # Same when scanning the table
+    items = table.scan(IndexName="GSI-INC")["Items"]
+    items[0].should.equal(
+        {
+            "gsiK1PartitionKey": "gsi-pk",
+            "gsiK1SortKey": "gsi-sk",
+            "partitionKey": "pk-1",
+            "projectedAttribute": "lore ipsum",
+        }
+    )
+
 
 @mock_dynamodb
 def test_lsi_projection_type_keys_only():
@@ -4756,6 +4767,12 @@ def test_lsi_projection_type_keys_only():
         {"partitionKey": "pk-1", "sortKey": "sk-1", "lsiK1SortKey": "lsi-sk"}
     )
 
+    # Same when scanning the table
+    items = table.scan(IndexName="LSI")["Items"]
+    items[0].should.equal(
+        {"lsiK1SortKey": "lsi-sk", "partitionKey": "pk-1", "sortKey": "sk-1"}
+    )
+
 
 @mock_dynamodb
 @pytest.mark.parametrize(