Feature/api improvments

offline_debug/__init__.py

@@ -1,6 +1,7 @@
 """Tool for serializing and reconstructing Python exceptions with full stack traces."""
 
-from ._inner.load_traceback import load_traceback
+from ._inner.load_traceback import load_traceback, parse_traceback
+from ._inner.models import ExceptionData, FrameData
 from ._inner.save_traceback import save_traceback
 
-__all__ = ["load_traceback", "save_traceback"]
+__all__ = ["ExceptionData", "FrameData", "load_traceback", "parse_traceback", "save_traceback"]

offline_debug/_inner/load_traceback.py

@@ -7,19 +7,18 @@
 from io import BytesIO
 from pathlib import Path
 from types import CodeType
-from typing import Never
 
 from offline_debug._inner.c_api import (
     create_frame,
     link_frame,
 )
 from offline_debug._inner.models import (
-    _ExceptionData,
-    _FrameData,
+    ExceptionData,
+    FrameData,
 )
 
 
-def _reconstruct_exc_data(data: _ExceptionData) -> BaseException:
+def _reconstruct_exc_data(data: ExceptionData) -> BaseException:
     """
     Recursively reconstruct an exception from its serialized data.
 
@@ -37,26 +36,25 @@ def _reconstruct_exc_data(data: _ExceptionData) -> BaseException:
         msg = f"Expected BaseException, but got {type(exc).__name__}"
         raise TypeError(msg)
 
-    reconstructed_frames: list[tuple[types.FrameType, _FrameData]] = []
+    reconstructed_frames: list[tuple[types.FrameType, FrameData]] = []
     for f_data in data.tb_frames:
         code: CodeType = marshal.loads(f_data.code)  # noqa: S302
 
-        # In Python 3.11 and 3.12, accessing f_locals on a frame created via
+        # In Python 3.11+, accessing f_locals on a frame created via
         # PyFrame_New for optimized code (functions) causes a segmentation fault
         # because the internal 'fast' locals array is not initialized.
         # As a workaround, we create a 'non-optimized' version of the code object
         # by compiling a dummy string. This ensures the bytecode is safe
         # (no LOAD_FAST) while preserving metadata like name and filename.
-        if sys.version_info < (3, 13):
-            # A simple module-level code object never has fast locals.
-            # Since the source is empty, no optimized locals will be created.
-            # Instead, python will go to the unoptimized dictionary we set under frame_locals later.
-            unoptimized_code = compile("", code.co_filename, "exec")
-            code = unoptimized_code.replace(
-                co_name=code.co_name,
-                co_firstlineno=code.co_firstlineno,
-                co_qualname=code.co_qualname,
-            )
+        # A simple module-level code object never has fast locals.
+        # Since the source is empty, no optimized locals will be created.
+        # Instead, python will go to the unoptimized dictionary we set under frame_locals later.
+        unoptimized_code = compile("", code.co_filename, "exec")
+        code = unoptimized_code.replace(
+            co_name=code.co_name,
+            co_firstlineno=code.co_firstlineno,
+            co_qualname=code.co_qualname,
+        )
 
         # PyFrame_New returns a new reference to a PyFrameObject.
         if f_data.module_name:
@@ -92,17 +90,22 @@ def _reconstruct_exc_data(data: _ExceptionData) -> BaseException:
     return exc
 
 
-def load_traceback(file: Path | BytesIO) -> Never:
-    """Load an exception and its traceback from a file and raise it."""
+def parse_traceback(file: Path | BytesIO) -> ExceptionData:
     if isinstance(file, Path):
         with file.open("rb") as f:
             data = pickle.load(f)  # noqa: S301
     else:
         data = pickle.load(file)  # noqa: S301
 
-    if not isinstance(data, _ExceptionData):
+    if not isinstance(data, ExceptionData):
         msg = f"Expected _ExceptionData, but got {type(data).__name__}"
         raise TypeError(msg)
+    return data
+
+
+def load_traceback(file: Path | BytesIO, should_raise: bool = True) -> BaseException:  # noqa: FBT001, FBT002
+    """Load an exception and its traceback from a file and raise it."""
+    data = parse_traceback(file)
 
     exc = _reconstruct_exc_data(data)
 
@@ -126,4 +129,6 @@ def load_traceback(file: Path | BytesIO) -> Never:
         )
 
     exc = exc.with_traceback(tb_chain)
-    raise exc
+    if should_raise:
+        raise exc
+    return exc

offline_debug/_inner/models.py

@@ -7,7 +7,7 @@
 
 
 @dataclass
-class _FrameData:
+class FrameData:
     """Serialized data for a single stack frame."""
 
     code: bytes
@@ -20,10 +20,10 @@ class _FrameData:
 
 
 @dataclass
-class _ExceptionData:
+class ExceptionData:
     """Serialized data for an exception and its traceback."""
 
     exc_pickle: bytes
-    tb_frames: list[_FrameData]
-    cause: _ExceptionData | None = None
-    context: _ExceptionData | None = None
+    tb_frames: list[FrameData]
+    cause: ExceptionData | None = None
+    context: ExceptionData | None = None

offline_debug/_inner/save_traceback.py

@@ -6,7 +6,7 @@
 from io import BytesIO
 from pathlib import Path
 
-from offline_debug._inner.models import _ExceptionData, _FrameData
+from offline_debug._inner.models import ExceptionData, FrameData
 
 # Internal attributes that are either unpicklable or redundant in a new process.
 # We exclude these specifically because they are automatically recreated
@@ -41,9 +41,9 @@ def _filter_dict(d: dict) -> dict:
     return result
 
 
-def _serialize_exc_data(exc: BaseException) -> _ExceptionData:
+def _serialize_exc_data(exc: BaseException) -> ExceptionData:
     """Recursively serialize exception data into dataclasses."""
-    tb_frames: list[_FrameData] = []
+    tb_frames: list[FrameData] = []
     curr_tb = exc.__traceback__
     while curr_tb:
         f = curr_tb.tb_frame
@@ -58,7 +58,7 @@ def _serialize_exc_data(exc: BaseException) -> _ExceptionData:
                 mod_name = spec.name
 
         tb_frames.append(
-            _FrameData(
+            FrameData(
                 code=marshal.dumps(f.f_code),
                 globals=_filter_dict(f.f_globals),
                 locals=_filter_dict(f.f_locals),
@@ -77,17 +77,20 @@ def _serialize_exc_data(exc: BaseException) -> _ExceptionData:
             RuntimeError(f"Unpicklable exception {type(exc).__name__}: {exc!s}")
         )
 
-    return _ExceptionData(
+    return ExceptionData(
         exc_pickle=exc_pickle,
         tb_frames=tb_frames,
         cause=_serialize_exc_data(exc.__cause__) if exc.__cause__ else None,
         context=_serialize_exc_data(exc.__context__) if exc.__context__ else None,
     )
 
 
-def save_traceback(exc: BaseException, file: Path | BytesIO) -> None:
+def save_traceback(exc: BaseException, file: Path | BytesIO | None) -> ExceptionData:
     """Serialize an exception and its traceback to a file."""
     data = _serialize_exc_data(exc)
+    if file is None:
+        return data
+
     if isinstance(file, Path):
         with file.open("wb") as f:
             pickle.dump(data, f)
@@ -96,3 +99,4 @@ def save_traceback(exc: BaseException, file: Path | BytesIO) -> None:
     else:
         msg = f"Unexpected type for file {type(file).__name__}"
         raise TypeError(msg)
+    return data

pyproject.toml

@@ -1,12 +1,12 @@
 [project]
 name = "offline-debug"
-version = "0.2.0"
+version = "0.2.1"
 description = "Debug exceptions offline by saving them to a dump and raising them at a later point."
 readme = "README.md"
 authors = [
     { name = "Itai Elidan", email = "itaielidan@gmail.com" }
 ]
-requires-python = ">=3.12"
+requires-python = ">=3.12, <3.14"
 dependencies = [
     "typing-extensions>=4.15.0",
 ]

tests/_inner/test_load_traceback.py

@@ -2,12 +2,13 @@
 
 from __future__ import annotations
 
+from io import BytesIO
 from pathlib import Path
 from typing import TYPE_CHECKING
 
 import pytest
 
-from offline_debug import load_traceback
+from offline_debug import load_traceback, save_traceback
 
 if TYPE_CHECKING:
     import types
@@ -23,16 +24,6 @@ def get_frames(tb: types.TracebackType | None) -> list[types.FrameType]:
     return frames
 
 
-def test_typing_never() -> None:
-    """Test that load_traceback is correctly annotated with Never."""
-    import typing
-
-    from offline_debug import load_traceback
-
-    load_traceback_annotations = typing.get_type_hints(load_traceback)
-    assert load_traceback_annotations["return"] is typing.Never
-
-
 def test_load_invalid_object(tmp_path: Path) -> None:
     """Test that load_traceback raises TypeError when loading an invalid object."""
     import pickle
@@ -56,9 +47,9 @@ def test_reconstruct_invalid_exception_type() -> None:
     import pickle
 
     from offline_debug._inner.load_traceback import _reconstruct_exc_data
-    from offline_debug._inner.models import _ExceptionData
+    from offline_debug._inner.models import ExceptionData
 
-    data = _ExceptionData(
+    data = ExceptionData(
         exc_pickle=pickle.dumps("not an exception"),
         tb_frames=[],
     )
@@ -71,7 +62,7 @@ def test_reconstruct_invalid_frame_type(monkeypatch) -> None:
     """Test that _reconstruct_exc_data raises TypeError when frame creation fails."""
     import offline_debug._inner.c_api._create_frame as _create_frame_module
     from offline_debug._inner.load_traceback import _reconstruct_exc_data
-    from offline_debug._inner.models import _ExceptionData, _FrameData
+    from offline_debug._inner.models import ExceptionData, FrameData
 
     # Mock _get_py_frame_new to return a function that returns something that is not a FrameType
     monkeypatch.setattr(_create_frame_module, "_get_py_frame_new", lambda: lambda *_: "not a frame")
@@ -82,10 +73,10 @@ def test_reconstruct_invalid_frame_type(monkeypatch) -> None:
     def dummy() -> None:
         pass
 
-    data = _ExceptionData(
+    data = ExceptionData(
         exc_pickle=pickle.dumps(ValueError("test")),
         tb_frames=[
-            _FrameData(
+            FrameData(
                 code=marshal.dumps(dummy.__code__),
                 globals={},
                 locals={},
@@ -98,3 +89,15 @@ def dummy() -> None:
 
     with pytest.raises(TypeError, match=r"Expected types.FrameType, but got str"):
         _reconstruct_exc_data(data)
+
+
+def test_load_traceback_should_raise_false() -> None:
+    """Test load_traceback when should_raise is False."""
+    buffer = BytesIO()
+    exc = ValueError("test_raise_false")
+    save_traceback(exc, buffer)
+    buffer.seek(0)
+
+    loaded_exc = load_traceback(buffer, should_raise=False)
+    assert isinstance(loaded_exc, ValueError)
+    assert str(loaded_exc) == "test_raise_false"

tests/_inner/test_save_traceback.py

@@ -7,7 +7,7 @@
 
 import pytest
 
-from offline_debug import load_traceback, save_traceback
+from offline_debug import ExceptionData, load_traceback, save_traceback
 
 if TYPE_CHECKING:
     from collections.abc import Callable
@@ -162,3 +162,10 @@ def raise_unpicklable() -> Never:
 
     with pytest.raises(RuntimeError, match="Unpicklable exception UnpicklableError: Unpicklable"):
         load_traceback(dump_file)
+
+
+def test_save_traceback_file_none() -> None:
+    """Test save_traceback when file is None."""
+    exc = ValueError("test")
+    data = save_traceback(exc, None)
+    assert isinstance(data, ExceptionData)