fix(mappers): Schema passthrough for whitelisted fields

docs/CONTRIBUTING.md

@@ -114,12 +114,43 @@ Supported platform markers are `windows`, `darwin`, and `linux`.
 ### Snapshot Testing
 
 We use [pytest-snapshot](https://pypi.org/project/pytest-snapshot/) for snapshot testing.
-To update snapshots, run:
+
+#### Adding a new snapshot
+
+To add a new snapshot, use the `snapshot` fixture and mark the test with the
+`@pytest.mark.snapshot` decorator. The fixture will create a new snapshot file
+if one does not already exist. If a snapshot file already exists, the fixture
+will compare the snapshot to the actual value and fail the test if they do not
+match.
+
+The `tests/snapshots` directory is where snapshot files should be stored and
+it's available as the `snapshot_dir` fixture.
+
+```python
+@pytest.mark.snapshot
+def test_snapshot(snapshot, snapshot_dir):
+    # Configure the snapshot directory
+    snapshot.snapshot_dir = snapshot_dir.joinpath("test_snapshot_subdir")
+
+    snapshot_name = "test_snapshot"
+    expected_content = "Hello, World!"
+    snapshot.assert_match(expected_content, snapshot_name)
+```
+
+#### Generating or updating snapshots
+
+To update or generate snapshots, run the nox `update_snapshots` session
 
 ```bash
 nox -rs update_snapshots
 ```
 
+or use the `--snapshot-update` flag
+
+```bash
+poetry run pytest --snapshot-update -m 'snapshot'
+```
+
 This will run all tests with the `snapshot` marker and update any snapshots that have changed.
 Commit the updated snapshots to your branch if they are expected to change.
 

singer_sdk/helpers/_typing.py

@@ -44,10 +44,11 @@ def append_type(type_dict: dict, new_type: str) -> dict:
         return result
 
     elif "type" in result:
-        if isinstance(result["type"], list) and new_type not in result["type"]:
-            result["type"].append(new_type)
-        elif new_type != result["type"]:
-            result["type"] = [result["type"], new_type]
+        type_array = (
+            result["type"] if isinstance(result["type"], list) else [result["type"]]
+        )
+        if new_type not in type_array:
+            result["type"] = [*type_array, new_type]
         return result
 
     raise ValueError(

singer_sdk/mapper.py

@@ -429,8 +429,11 @@ def _init_functions_and_schema(
                 transformed_schema["properties"].pop(prop_key, None)
             elif isinstance(prop_def, str):
                 default_type: JSONTypeHelper = StringType()  # Fallback to string
-                existing_schema: dict = transformed_schema["properties"].get(
-                    prop_key, {}
+                existing_schema: dict = (
+                    # Use transformed schema if available
+                    transformed_schema["properties"].get(prop_key, {})
+                    # ...or original schema for passthrough
+                    or self.raw_schema["properties"].get(prop_def, {})
                 )
                 if existing_schema:
                     # Set default type if property exists already in JSON Schema

tests/core/test_mapper.py

@@ -1,11 +1,16 @@
 """Test map transformer."""
 
 import copy
+import io
 import json
 import logging
-from typing import Dict, List, Optional, Set, cast
+from contextlib import redirect_stdout
+from pathlib import Path
+from typing import Dict, List, Optional
 
 import pytest
+from freezegun import freeze_time
+from pytest_snapshot.plugin import Snapshot
 
 from singer_sdk._singerlib import Catalog
 from singer_sdk.exceptions import MapExpressionError
@@ -444,31 +449,30 @@ def clear_schema_cache() -> None:
     get_selected_schema.cache_clear()
 
 
+@freeze_time("2022-01-01T00:00:00Z")
+@pytest.mark.snapshot
 @pytest.mark.parametrize(
-    "stream_alias,stream_maps,flatten,flatten_max_depth,output_fields,key_properties",
+    "stream_maps,flatten,flatten_max_depth,snapshot_name",
     [
-        (
-            "mystream",
+        pytest.param(
             {},
             False,
             0,
-            {"email", "count", "user"},
-            [],
+            "no_map.jsonl",
+            id="no_map",
         ),
-        (
-            "mystream",
+        pytest.param(
             {
                 "mystream": {
                     "email_hash": "md5(email)",
                 }
             },
             False,
             0,
-            {"email", "count", "user", "email_hash"},
-            [],
+            "keep_all_fields.jsonl",
+            id="keep_all_fields",
         ),
-        (
-            "mystream",
+        pytest.param(
             {
                 "mystream": {
                     "email_hash": "md5(email)",
@@ -478,11 +482,10 @@ def clear_schema_cache() -> None:
             },
             False,
             0,
-            {"fixed_count", "email_hash"},
-            [],
+            "only_mapped_fields.jsonl",
+            id="only_mapped_fields",
         ),
-        (
-            "mystream",
+        pytest.param(
             {
                 "mystream": {
                     "email_hash": "md5(email)",
@@ -492,51 +495,45 @@ def clear_schema_cache() -> None:
             },
             False,
             0,
-            {"email_hash"},
-            ["email_hash"],
+            "changed_key_properties.jsonl",
+            id="changed_key_properties",
         ),
-        (
-            "sourced_stream_1",
+        pytest.param(
             {"mystream": None, "sourced_stream_1": {"__source__": "mystream"}},
             False,
             0,
-            {"email", "count", "user"},
-            [],
+            "sourced_stream_1.jsonl",
+            id="sourced_stream_1",
         ),
-        (
-            "sourced_stream_2",
+        pytest.param(
             {"sourced_stream_2": {"__source__": "mystream"}, "__else__": None},
             False,
             0,
-            {"email", "count", "user"},
-            [],
+            "sourced_stream_2.jsonl",
+            id="sourced_stream_2",
         ),
-        (
-            "aliased_stream",
+        pytest.param(
             {"mystream": {"__alias__": "aliased_stream"}},
             False,
             0,
-            {"email", "count", "user"},
-            [],
+            "aliased_stream.jsonl",
+            id="aliased_stream",
         ),
-        (
-            "mystream",
+        pytest.param(
             {},
             True,
             1,
-            {"email", "count", "user__id", "user__sub"},
-            [],
+            "flatten_depth_1.jsonl",
+            id="flatten_depth_1",
         ),
-        (
-            "mystream",
+        pytest.param(
             {},
             True,
             10,
-            {"email", "count", "user__id", "user__sub__num"},
-            [],
+            "flatten_all.jsonl",
+            id="flatten_all",
         ),
-        (
-            "mystream",
+        pytest.param(
             {
                 "mystream": {
                     "email_hash": "md5(email)",
@@ -545,69 +542,55 @@ def clear_schema_cache() -> None:
             },
             True,
             10,
-            {"email", "count", "email_hash", "user__id", "user__sub__num"},
-            ["email_hash"],
+            "map_and_flatten.jsonl",
+            id="map_and_flatten",
         ),
-        (
-            "mystream",
+        pytest.param(
             {
                 "mystream": {
                     "email": None,
                 }
             },
             False,
             0,
-            {"count", "user"},
-            [],
+            "drop_property.jsonl",
+            id="drop_property",
+        ),
+        pytest.param(
+            {
+                "mystream": {
+                    "count": "count",
+                    "__else__": None,
+                }
+            },
+            False,
+            0,
+            "non_pk_passthrough.jsonl",
+            id="non_pk_passthrough",
         ),
-    ],
-    ids=[
-        "no_map",
-        "keep_all_fields",
-        "only_mapped_fields",
-        "changed_key_properties",
-        "sourced_stream_1",
-        "sourced_stream_2",
-        "aliased_stream",
-        "flatten_depth_1",
-        "flatten_all",
-        "map_and_flatten",
-        "drop_property",
     ],
 )
 def test_mapped_stream(
+    snapshot: Snapshot,
+    snapshot_dir: Path,
     clear_schema_cache: None,
-    stream_alias: str,
     stream_maps: dict,
     flatten: bool,
     flatten_max_depth: Optional[int],
-    output_fields: Set[str],
-    key_properties: List[str],
+    snapshot_name: str,
 ):
+    snapshot.snapshot_dir = snapshot_dir.joinpath("mapped_stream")
+
     tap = MappedTap(
         config={
             "stream_maps": stream_maps,
             "flattening_enabled": flatten,
             "flattening_max_depth": flatten_max_depth,
         }
     )
-    stream = tap.streams["mystream"]
-
-    schema_messages = list(stream._generate_schema_messages())
-    assert len(schema_messages) == 1, "Incorrect number of schema messages generated."
-    schema_message = schema_messages[0]
-    assert schema_message.stream == stream_alias
-    assert schema_message.key_properties == key_properties
-    assert schema_message.schema["properties"].keys() == output_fields
-
-    for raw_record in stream.get_records(None):
-        record_message = next(stream._generate_record_messages(cast(dict, raw_record)))
-        transformed_record = record_message.record
-
-        assert record_message.stream == stream_alias
-        assert output_fields == set(transformed_record.keys())
-
-        for output_field in output_fields:
-            assert transformed_record[
-                output_field
-            ], f"Value for field '{output_field}' should be nonempty."
+    buf = io.StringIO()
+    with redirect_stdout(buf):
+        tap.sync_all()
+
+    buf.seek(0)
+    snapshot.assert_match(buf.read(), snapshot_name)

tests/snapshots/mapped_stream/aliased_stream.jsonl

@@ -0,0 +1,7 @@
+{"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": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"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": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/changed_key_properties.jsonl

@@ -0,0 +1,7 @@
+{"type": "SCHEMA", "stream": "mystream", "schema": {"type": "object", "properties": {"email_hash": {"type": ["string", "null"]}}}, "key_properties": ["email_hash"]}
+{"type": "RECORD", "stream": "mystream", "record": {"email_hash": "c160f8cc69a4f0bf2b0362752353d060"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"type": "RECORD", "stream": "mystream", "record": {"email_hash": "4b9bb80620f03eb3719e0a061c14283d"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email_hash": "426b189df1e2f359efe6ee90f2d2030f"}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/drop_property.jsonl

@@ -0,0 +1,7 @@
+{"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": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"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": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/flatten_all.jsonl

@@ -0,0 +1,7 @@
+{"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": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"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": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/flatten_depth_1.jsonl

@@ -0,0 +1,7 @@
+{"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": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"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": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/keep_all_fields.jsonl

@@ -0,0 +1,7 @@
+{"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": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"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": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/map_and_flatten.jsonl

@@ -0,0 +1,7 @@
+{"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": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"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": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/no_map.jsonl

@@ -0,0 +1,7 @@
+{"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"]}}, "type": "object"}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 21, "user": {"id": 1, "sub": {"num": 1}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"type": "RECORD", "stream": "mystream", "record": {"email": "[email protected]", "count": 13, "user": {"id": 2, "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, "sub": {"num": 3}}}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/non_pk_passthrough.jsonl

@@ -0,0 +1,7 @@
+{"type": "SCHEMA", "stream": "mystream", "schema": {"type": "object", "properties": {"count": {"type": ["integer", "null"]}}}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 21}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 13}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"count": 19}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}

tests/snapshots/mapped_stream/only_mapped_fields.jsonl

@@ -0,0 +1,7 @@
+{"type": "SCHEMA", "stream": "mystream", "schema": {"type": "object", "properties": {"email_hash": {"type": ["string", "null"]}, "fixed_count": {"type": ["integer", "null"]}}}, "key_properties": []}
+{"type": "RECORD", "stream": "mystream", "record": {"email_hash": "c160f8cc69a4f0bf2b0362752353d060", "fixed_count": 20}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {"starting_replication_value": null}}}}
+{"type": "RECORD", "stream": "mystream", "record": {"email_hash": "4b9bb80620f03eb3719e0a061c14283d", "fixed_count": 12}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "RECORD", "stream": "mystream", "record": {"email_hash": "426b189df1e2f359efe6ee90f2d2030f", "fixed_count": 18}, "time_extracted": "2022-01-01T00:00:00+00:00"}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}
+{"type": "STATE", "value": {"bookmarks": {"mystream": {}}}}