add encoder for list when using native types

snowfakery/data_generator_runtime_object_model.py

@@ -19,7 +19,10 @@
 # objects that represent the hierarchy of a data generator.
 # roughly similar to the YAML structure but with domain-specific objects
 Definition = Union["ObjectTemplate", "SimpleValue", "StructuredValue"]
-FieldValue = Union[None, Scalar, ObjectRow, tuple, PluginResult, ObjectReference]
+FieldValue = Union[
+    None, bool, int, float, str, bytes, list, dict, tuple, set,
+    Scalar, ObjectRow, PluginResult, ObjectReference
+]
 
 
 class FieldDefinition(ABC):

snowfakery/output_streams.py

@@ -61,6 +61,11 @@ class OutputStream(ABC):
         type(None): noop,
         bool: int,
         Decimal: str,
+        list: lambda data: json.dumps(data),
+        dict: lambda data: json.dumps(data),
+        bytes: str,
+        tuple: lambda data: data,
+        set: lambda data: data,
     }
     uses_folder = False
     uses_path = False

tests/test_output_streams.py

@@ -353,6 +353,7 @@ def do_output(self, yaml):
 
     def test_csv_output(self):
         yaml = """
+        - snowfakery_version: 3
         - object: foo
           fields:
             a: 1
@@ -365,6 +366,13 @@ def test_csv_output(self):
           fields:
             barb: 2
             bard: 4
+        - object: faz
+          fields:
+            list_t: ${{fake.json(data_columns={'Spec':'@1.0.1', 'ID':'pyint','Details':{'Name':'name', 'Address':'address'}}, num_rows=2)}}
+            dict_t: ${{fake.json(data_columns={'Spec':'@1.0.1', 'ID':'pyint','Details':{'Name':'name', 'Address':'address'}}, num_rows=1)}}
+            bool_t: ${{fake.pybool()}}
+            tuple_t: ${{(1, 2)}}
+            bytes_t: ${{fake.binary(length=64)}}
         """
         with TemporaryDirectory() as t:
             output_stream = CSVOutputStream(Path(t) / "csvoutput")
@@ -373,13 +381,15 @@ def test_csv_output(self):
             assert messages
             assert "foo.csv" in messages[0]
             assert "bar.csv" in messages[1]
-            assert "csvw" in messages[2]
+            assert "faz.csv" in messages[2]
+            assert "csvw" in messages[3]
             assert (Path(t) / "csvoutput" / "foo.csv").exists()
             with open(Path(t) / "csvoutput" / "csvw_metadata.json") as f:
                 metadata = json.load(f)
                 assert {table["url"] for table in metadata["tables"]} == {
                     "foo.csv",
                     "bar.csv",
+                    "faz.csv",
                 }
 
     def test_null(self):