[stefankoegl]

Supersedes #126 (originally by sammaphey), re-applied on top of current master.

Changes

• JsonPatchException accepts an optional op keyword argument and exposes it as exc.op (defaults to None, so existing callers are unaffected).
• Every JsonPatchException (InvalidJsonPatch, JsonPatchConflict, JsonPatchTestFailed) raised by this library while constructing or applying a patch carries the failing operation:
  • the PatchOperation instance for errors raised from an operation's methods (apply, _from_pointer);
  • for move and copy, the enclosing MoveOperation / CopyOperation, also when the failure happens in the internal remove/add step they delegate to;
  • the raw operation object for errors raised before an operation could be constructed (PatchOperation.__init__, JsonPatch._get_operation, and string entries rejected in JsonPatch.__init__).

Out of scope

JsonPointerException raised by the jsonpointer library (e.g. a path not starting with /, or a pointer that cannot be resolved against the document) is not a JsonPatchException subclass and is left unchanged — it does not have an op attribute. Converting those into JsonPatchExceptions would change which exceptions callers see and is better handled in a separate PR.

Difference from #126

The original constructor was __init__(self, op=None), so JsonPatchConflict(msg, op=self) raised TypeError: got multiple values for argument 'op', and the message never reached Exception. The new constructor pops op from kwargs and forwards the remaining args to Exception.__init__.

Tests

ExceptionOperationTests covers: conflict, failed test operation, invalid operation carrying the raw dict, string entry carrying the raw string, move failing in its add and remove steps, copy failing in its add step, and op defaulting to None. pytest: 255 passed; python tests.py: OK.

🤖 Generated with Claude Code

https://claude.ai/code/session_01PewzpkvyJUvFMnnjKxmyNd

[coveralls]

coverage: 100.0%. remained the same — claude/confident-curie-9x5ahd into master

[Copilot]

🟡 Changes recommended

Exception attribution remains incomplete: delegated move/copy failures report synthetic operations, while rejected string entries leave op unset, preventing callers from reliably identifying the original failing operation.

2 open issues

• Report delegated move and copy failures against the original operation · New
• Include the raw operation in string-entry validation errors · New

What changed in this PR

Adds operation context to JSON Patch exceptions so callers can inspect the failing operation while preserving existing exception messages.

Changes:

• Adds an optional op argument and attribute to JsonPatchException.
• Attaches operation instances or raw operation objects at exception sites.
• Adds regression tests for operation context, message preservation, and the default None value.

File	Description
tests.py	Adds exception-context tests and registers them in the test suite.
jsonpatch.py	Extends the base exception and attaches operation context to patch errors.

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

JSON-pointer exceptions during construction and application still lack the raw operation context, leaving the stated exception-context guarantee unmet.

No open issues 🎉

1 previously missed issue

In code that hasn't changed since last review

JSON-pointer exceptions omit operation context

jsonpatch.py:199

JSON-pointer errors still escape without op: constructing {'op': 'add', 'path': 'foo', 'value': 1} raises JsonPointerException without the raw operation, and pointer-resolution failures during application also bypass these annotations. This leaves the description's guarantee of operation context on every construction/application exception unmet. Either attach the operation when re-raising pointer exceptions, preserving their existing type, or narrow the stated guarantee to JsonPatchException subclasses.

2 resolved since last review

• Include the raw operation in string-entry validation errors
• Report delegated move and copy failures against the original operation

_{Review effort: Balanced}