fix: Handle decimal.Decimal instances in flattening

singer_sdk/helpers/_flattening.py

@@ -4,12 +4,12 @@
 
 import collections
 import itertools
-import json
 import re
 import typing as t
 from copy import deepcopy
 
 import inflection
+import simplejson as json
 
 DEFAULT_FLATTENING_SEPARATOR = "__"
 
@@ -155,17 +155,7 @@ def flatten_schema(
           "type": "string"
         },
         "foo__bar": {
-          "type": "object",
-          "properties": {
-            "baz": {
-              "type": "object",
-              "properties": {
-                "qux": {
-                  "type": "string"
-                }
-              }
-            }
-          }
+          "type": "string"
         }
       }
     }
@@ -178,12 +168,7 @@ def flatten_schema(
           "type": "string"
         },
         "foo__bar__baz": {
-          "type": "object",
-          "properties": {
-            "qux": {
-              "type": "string"
-            }
-          }
+          "type": "string"
         }
       }
     }
@@ -210,7 +195,7 @@ def flatten_schema(
     return new_schema
 
 
-def _flatten_schema(  # noqa: C901
+def _flatten_schema(  # noqa: C901, PLR0912
     schema_node: dict,
     parent_keys: list[str] | None = None,
     separator: str = "__",
@@ -249,6 +234,8 @@ def _flatten_schema(  # noqa: C901
                         max_level=max_level,
                     ).items(),
                 )
+            elif "array" in v["type"] or "object" in v["type"] and max_level > 0:
+                items.append((new_key, {"type": "string"}))
             else:
                 items.append((new_key, v))
         elif len(v.values()) > 0:
@@ -347,7 +334,7 @@ def _flatten_record(
             items.append(
                 (
                     new_key,
-                    json.dumps(v)
+                    json.dumps(v, use_decimal=True)
                     if _should_jsondump_value(k, v, flattened_schema)
                     else v,
                 ),

tests/core/test_mapper.py

@@ -8,6 +8,7 @@
 import logging
 import typing as t
 from contextlib import redirect_stdout
+from decimal import Decimal
 
 import pytest
 from freezegun import freeze_time
@@ -19,7 +20,9 @@
 from singer_sdk.streams.core import Stream
 from singer_sdk.tap_base import Tap
 from singer_sdk.typing import (
+    ArrayType,
     IntegerType,
+    NumberType,
     ObjectType,
     PropertiesList,
     Property,
@@ -415,6 +418,7 @@ class MappedStream(Stream):
             ObjectType(
                 Property("id", IntegerType()),
                 Property("sub", ObjectType(Property("num", IntegerType()))),
+                Property("some_numbers", ArrayType(NumberType())),
             ),
         ),
     ).to_dict()
@@ -423,17 +427,29 @@ def get_records(self, context):  # noqa: ARG002
         yield {
             "email": "[email protected]",
             "count": 21,
-            "user": {"id": 1, "sub": {"num": 1}},
+            "user": {
+                "id": 1,
+                "sub": {"num": 1},
+                "some_numbers": [Decimal("3.14"), Decimal("2.718")],
+            },
         }
         yield {
             "email": "[email protected]",
             "count": 13,
-            "user": {"id": 2, "sub": {"num": 2}},
+            "user": {
+                "id": 2,
+                "sub": {"num": 2},
+                "some_numbers": [Decimal("10.32"), Decimal("1.618")],
+            },
         }
         yield {
             "email": "[email protected]",
             "count": 19,
-            "user": {"id": 3, "sub": {"num": 3}},
+            "user": {
+                "id": 3,
+                "sub": {"num": 3},
+                "some_numbers": [Decimal("1.414"), Decimal("1.732")],
+            },
         }
 
 
@@ -545,6 +561,13 @@ def _clear_schema_cache() -> None:
             "aliased_stream.jsonl",
             id="aliased_stream",
         ),
+        pytest.param(
+            {},
+            True,
+            0,
+            "flatten_depth_0.jsonl",
+            id="flatten_depth_0",
+        ),
         pytest.param(
             {},
             True,

tests/snapshots/mapped_stream/aliased_stream.jsonl

@@ -1,6 +1,6 @@
 {"type": "STATE", "value": {}}
-{"type": "SCHEMA", "stream": "aliased_stream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
-{"type": "RECORD", "stream": "aliased_stream", "record": {"email": "[email protected]", "count": 21, "user": {"id": 1, "sub": {"num": 1}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "aliased_stream", "record": {"email": "[email protected]", "count": 13, "user": {"id": 2, "sub": {"num": 2}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "aliased_stream", "record": {"email": "[email protected]", "count": 19, "user": {"id": 3, "sub": {"num": 3}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "SCHEMA", "stream": "aliased_stream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}, "some_numbers": {"items": {"type": ["number"]}, "type": ["array", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "aliased_stream", "record": {"email": "[email protected]", "count": 21, "user": {"id": 1, "sub": {"num": 1}, "some_numbers": [3.14, 2.718]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "aliased_stream", "record": {"email": "[email protected]", "count": 13, "user": {"id": 2, "sub": {"num": 2}, "some_numbers": [10.32, 1.618]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "aliased_stream", "record": {"email": "[email protected]", "count": 19, "user": {"id": 3, "sub": {"num": 3}, "some_numbers": [1.414, 1.732]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
 {"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/drop_property.jsonl

@@ -1,6 +1,6 @@
 {"type": "STATE", "value": {}}
-{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
-{"type": "RECORD", "stream": "mystream", "record": {"count": 21, "user": {"id": 1, "sub": {"num": 1}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"count": 13, "user": {"id": 2, "sub": {"num": 2}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"count": 19, "user": {"id": 3, "sub": {"num": 3}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}, "some_numbers": {"items": {"type": ["number"]}, "type": ["array", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 21, "user": {"id": 1, "sub": {"num": 1}, "some_numbers": [3.14, 2.718]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 13, "user": {"id": 2, "sub": {"num": 2}, "some_numbers": [10.32, 1.618]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 19, "user": {"id": 3, "sub": {"num": 3}, "some_numbers": [1.414, 1.732]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
 {"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/drop_property_null_string.jsonl

@@ -1,6 +1,6 @@
 {"type": "STATE", "value": {}}
-{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
-{"type": "RECORD", "stream": "mystream", "record": {"count": 21, "user": {"id": 1, "sub": {"num": 1}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"count": 13, "user": {"id": 2, "sub": {"num": 2}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"count": 19, "user": {"id": 3, "sub": {"num": 3}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}, "some_numbers": {"items": {"type": ["number"]}, "type": ["array", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 21, "user": {"id": 1, "sub": {"num": 1}, "some_numbers": [3.14, 2.718]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 13, "user": {"id": 2, "sub": {"num": 2}, "some_numbers": [10.32, 1.618]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 19, "user": {"id": 3, "sub": {"num": 3}, "some_numbers": [1.414, 1.732]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
 {"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/flatten_all.jsonl

@@ -1,6 +1,6 @@
 {"type": "STATE", "value": {}}
-{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user__id": {"type": ["integer", "null"]}, "user__sub__num": {"type": ["integer", "null"]}}, "type": "object"}, "key_properties": []}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user__id": 1, "user__sub__num": 1}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user__id": 2, "user__sub__num": 2}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user__id": 3, "user__sub__num": 3}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user__id": {"type": ["integer", "null"]}, "user__sub__num": {"type": ["integer", "null"]}, "user__some_numbers": {"type": "string"}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user__id": 1, "user__sub__num": 1, "user__some_numbers": "[3.14, 2.718]"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user__id": 2, "user__sub__num": 2, "user__some_numbers": "[10.32, 1.618]"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user__id": 3, "user__sub__num": 3, "user__some_numbers": "[1.414, 1.732]"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
 {"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/flatten_depth_0.jsonl

@@ -0,0 +1,6 @@
+{"type": "STATE", "value": {}}
+{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}, "some_numbers": {"items": {"type": ["number"]}, "type": ["array", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user": {"id": 1, "sub": {"num": 1}, "some_numbers": [3.14, 2.718]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user": {"id": 2, "sub": {"num": 2}, "some_numbers": [10.32, 1.618]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user": {"id": 3, "sub": {"num": 3}, "some_numbers": [1.414, 1.732]}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/flatten_depth_1.jsonl

@@ -1,6 +1,6 @@
 {"type": "STATE", "value": {}}
-{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user__id": {"type": ["integer", "null"]}, "user__sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}}, "type": "object"}, "key_properties": []}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user__id": 1, "user__sub": "{\"num\": 1}"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user__id": 2, "user__sub": "{\"num\": 2}"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user__id": 3, "user__sub": "{\"num\": 3}"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user__id": {"type": ["integer", "null"]}, "user__sub": {"type": "string"}, "user__some_numbers": {"type": "string"}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user__id": 1, "user__sub": "{\"num\": 1}", "user__some_numbers": "[3.14, 2.718]"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user__id": 2, "user__sub": "{\"num\": 2}", "user__some_numbers": "[10.32, 1.618]"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user__id": 3, "user__sub": "{\"num\": 3}", "user__some_numbers": "[1.414, 1.732]"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
 {"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/keep_all_fields.jsonl

@@ -1,6 +1,6 @@
 {"type": "STATE", "value": {}}
-{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}}, "type": ["object", "null"]}, "email_hash": {"type": ["string", "null"]}}, "type": "object"}, "key_properties": []}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user": {"id": 1, "sub": {"num": 1}}, "email_hash": "c160f8cc69a4f0bf2b0362752353d060"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user": {"id": 2, "sub": {"num": 2}}, "email_hash": "4b9bb80620f03eb3719e0a061c14283d"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user": {"id": 3, "sub": {"num": 3}}, "email_hash": "426b189df1e2f359efe6ee90f2d2030f"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user": {"properties": {"id": {"type": ["integer", "null"]}, "sub": {"properties": {"num": {"type": ["integer", "null"]}}, "type": ["object", "null"]}, "some_numbers": {"items": {"type": ["number"]}, "type": ["array", "null"]}}, "type": ["object", "null"]}, "email_hash": {"type": ["string", "null"]}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user": {"id": 1, "sub": {"num": 1}, "some_numbers": [3.14, 2.718]}, "email_hash": "c160f8cc69a4f0bf2b0362752353d060"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user": {"id": 2, "sub": {"num": 2}, "some_numbers": [10.32, 1.618]}, "email_hash": "4b9bb80620f03eb3719e0a061c14283d"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user": {"id": 3, "sub": {"num": 3}, "some_numbers": [1.414, 1.732]}, "email_hash": "426b189df1e2f359efe6ee90f2d2030f"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
 {"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/map_and_flatten.jsonl

@@ -1,6 +1,6 @@
 {"type": "STATE", "value": {}}
-{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user__id": {"type": ["integer", "null"]}, "user__sub__num": {"type": ["integer", "null"]}, "email_hash": {"type": ["string", "null"]}}, "type": "object"}, "key_properties": ["email_hash"]}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user__id": 1, "user__sub__num": 1, "email_hash": "c160f8cc69a4f0bf2b0362752353d060"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user__id": 2, "user__sub__num": 2, "email_hash": "4b9bb80620f03eb3719e0a061c14283d"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
-{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user__id": 3, "user__sub__num": 3, "email_hash": "426b189df1e2f359efe6ee90f2d2030f"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "SCHEMA", "stream": "mystream", "schema": {"properties": {"email": {"type": ["string", "null"]}, "count": {"type": ["integer", "null"]}, "user__id": {"type": ["integer", "null"]}, "user__sub__num": {"type": ["integer", "null"]}, "user__some_numbers": {"type": "string"}, "email_hash": {"type": ["string", "null"]}}, "type": "object"}, "key_properties": ["email_hash"]}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user__id": 1, "user__sub__num": 1, "user__some_numbers": "[3.14, 2.718]", "email_hash": "c160f8cc69a4f0bf2b0362752353d060"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user__id": 2, "user__sub__num": 2, "user__some_numbers": "[10.32, 1.618]", "email_hash": "4b9bb80620f03eb3719e0a061c14283d"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 19, "user__id": 3, "user__sub__num": 3, "user__some_numbers": "[1.414, 1.732]", "email_hash": "426b189df1e2f359efe6ee90f2d2030f"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
 {"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}