[stefankoegl]

Refs #123

What

Adds JsonPatchPathNotFound, a subclass of JsonPatchConflict. It is raised when:

• a remove targets a missing object member or array element
• a replace targets a missing member, or an index past the end of a list
• a move or copy has a from that doesn't exist

Other conflicts still raise plain JsonPatchConflict: removing the whole document, inserting outside a list, moving a value into its own child, or changing an immutable container. Messages are unchanged, and the failing operation is still attached as .op.

Why

Issue #123 asks for a way to treat removing an already-absent key as success. RFC 6902 requires that case to fail, so the default stays as it is. The new exception lets callers tell a missing location apart from other conflicts.

Docs

A new tutorial section, "Ignoring Missing Locations", explains that catching the exception around apply() stops the rest of the patch. It recommends a JsonPatch subclass whose operations map uses a RemoveOperation that ignores JsonPatchPathNotFound, and notes that this doesn't conform to RFC 6902. The tutorial examples run as doctests.

Compatibility notes

• Existing except JsonPatchConflict handlers keep working.
• The jsonpatch command prints the traceback, so its error output now shows jsonpatch.JsonPatchPathNotFound instead of jsonpatch.JsonPatchConflict in these cases. The command-line test checks for the new name.
• A missing parent (e.g. removing /missing/key) still raises JsonPointerException, so the documented recipe doesn't skip it. This PR doesn't change that.

Tests

New PathNotFoundTests cover each case above, check that other conflicts don't use the new exception, and run the tutorial recipe. All 265 tests pass.

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Generated by Claude Code

[coveralls]

coverage: 100.0%. remained the same — claude/amazing-ramanujan-ge4irs into master

[Copilot]

🟢 Approval recommended

No active review issues are recorded for the missing-path exception and opt-in idempotent removal changes.

No open issues 🎉

What changed in this PR

Adds JsonPatchPathNotFound so callers can distinguish missing locations from other patch conflicts, supporting issue #123’s request for opt-in idempotent removal while preserving the default failure behavior.

Changes:

• Raises the new JsonPatchConflict subclass for missing remove/replace targets and move/copy sources.
• Documents a custom remove operation that skips missing locations and explains its limitations.
• Adds exception and customization tests and updates the expected command-line error name.

File	Description
tests.py	Tests missing-location errors, other conflicts, and the idempotent removal recipe.
jsonpatch.py	Defines and raises JsonPatchPathNotFound for applicable missing locations.
doc/​tutorial.rst	Explains the exception and documents opt-in idempotent removal.

_{Review effort: Balanced}