refactor: Remove dependency on pipelinewise-singer-python and move singer library code into singer_sdk._singerlib

.flake8

@@ -11,6 +11,8 @@ per-file-ignores =
     singer_sdk/helpers/_*.py:ANN,DAR,D105
     # Don't require docstrings conventions in "meta" code
     # singer_sdk/helpers/_classproperty.py:D105
+    # Ignore unused imports in __init__.py files
+    singer_sdk/_singerlib/__init__.py:F401
 max-complexity = 10
 docstring-convention = google
 allow-star-arg-any = true

noxfile.py

@@ -40,6 +40,8 @@ def mypy(session: Session) -> None:
         "sqlalchemy2-stubs",
         "types-python-dateutil",
         "types-requests",
+        "types-pytz",
+        "types-simplejson",
     )
     session.run("mypy", *args)
     if not session.posargs:

pyproject.toml

@@ -36,7 +36,6 @@ license = "Apache 2.0"
 
 [tool.poetry.dependencies]
 python = "<3.11,>=3.7.1"
-pipelinewise-singer-python = "1.2.0"
 backoff = ">=1.8.0,<2.0"
 pendulum = "^2.1.0"
 click = "~=8.0"
@@ -52,6 +51,9 @@ inflection = "^0.5.1"
 sqlalchemy = "^1.4"
 python-dotenv = ">=0.20,<0.22"
 typing-extensions = "^4.2.0"
+simplejson = "^3.17.6"
+jsonschema = "^4.16.0"
+pytz = "^2022.2.1"
 
 # Sphinx dependencies installed as optional 'docs' extras
 # https://github.com/readthedocs/readthedocs.org/issues/4912#issuecomment-664002569
@@ -84,7 +86,9 @@ viztracer = "^0.15.4"
 requests-mock = "^1.10.0"
 sqlalchemy2-stubs = {version = "^0.0.2a27", allow-prereleases = true}
 types-python-dateutil = "^2.8.19"
+types-pytz = "^2022.2.1.0"
 types-requests = "^2.28.11"
+types-simplejson = "^3.17.7"
 coverage = {extras = ["toml"], version = "^6.4"}
 
 # Cookiecutter tests
@@ -149,7 +153,7 @@ exclude_lines = [
     "if __name__ == .__main__.:",
     '''class .*\bProtocol\):''',
     '''@(abc\.)?abstractmethod''',
-    "if TYPE_CHECKING:",
+    '''if (t\.)?TYPE_CHECKING:''',
 ]
 fail_under = 82
 

samples/sample_mapper/mapper.py

@@ -3,8 +3,7 @@
 from pathlib import PurePath
 from typing import Generator, List, Optional, Union
 
-import singer
-
+import singer_sdk._singerlib as singer
 import singer_sdk.typing as th
 from singer_sdk.helpers._util import utc_now
 from singer_sdk.mapper import PluginMapper

singer_sdk/_singerlib/__init__.py

@@ -0,0 +1,19 @@
+from singer_sdk._singerlib.catalog import (
+    Catalog,
+    CatalogEntry,
+    Metadata,
+    MetadataMapping,
+    SelectionMask,
+    StreamMetadata,
+)
+from singer_sdk._singerlib.messages import (
+    ActivateVersionMessage,
+    Message,
+    RecordMessage,
+    SchemaMessage,
+    SingerMessageType,
+    StateMessage,
+    exclude_null_dict,
+    write_message,
+)
+from singer_sdk._singerlib.schema import Schema, resolve_schema_references