[isabelatkinson]

Please complete the following before merging:

• Is the relevant DRIVERS ticket in the PR title?
• Update changelog.
• Test changes in at least one language driver.
• Test these changes against all server versions and topologies (including standalone, replica set, and sharded
  clusters).

Rust implementation: mongodb/mongo-rust-driver#1840

[isabelatkinson]

Note: the unified test runner spec doesn't currently support asserting on error codes for bulk errors. The purpose of these tests is to ensure that drivers aren't swallowing write concern errors, so it should be sufficient in these cases just to assert that an error was returned.

[Copilot]

🟡 Changes recommended

Missing data isolation in both bulk-write fixtures allows duplicate-key errors to mask failures to report write concern errors.

1 open issue

• Reset collection before write-concern error tests · New

What changed in this PR

This PR strengthens the MongoDB driver specification by requiring write concern errors to be reported and adding cross-driver tests for that behavior.

Changes:

• Changes write concern error reporting from SHOULD to MUST for methods accepting a WriteConcern.
• Adds failpoint-based unified tests and generated JSON across write-capable operations.
• Documents the new test suite and updates the specification changelog.

File	Description
source/​read-write-concern/​tests/​write-concern-errors/​mapReduce.yml	Tests error reporting for mapReduce output writes.
source/​read-write-concern/​tests/​write-concern-errors/​mapReduce.json	Generated mapReduce test.
source/​read-write-concern/​tests/​write-concern-errors/​index-management.yml	Tests index creation and deletion errors.
source/​read-write-concern/​tests/​write-concern-errors/​index-management.json	Generated index-management tests.
source/​read-write-concern/​tests/​write-concern-errors/​gridfs.yml	Tests chunk and file-document upload errors.
source/​read-write-concern/​tests/​write-concern-errors/​gridfs.json	Generated GridFS tests.
source/​read-write-concern/​tests/​write-concern-errors/​findAndModify.yml	Tests find-and-modify operation errors.
source/​read-write-concern/​tests/​write-concern-errors/​findAndModify.json	Generated find-and-modify tests.
source/​read-write-concern/​tests/​write-concern-errors/​db-coll-management.yml	Tests database and collection management errors.
source/​read-write-concern/​tests/​write-concern-errors/​db-coll-management.json	Generated database and collection tests.
source/​read-write-concern/​tests/​write-concern-errors/​crud.yml	Tests insert, update, replace, and delete errors.
source/​read-write-concern/​tests/​write-concern-errors/​crud.json	Generated CRUD tests.
source/​read-write-concern/​tests/​write-concern-errors/​client-side-encryption.yml	Tests data-key rewrapping errors.
source/​read-write-concern/​tests/​write-concern-errors/​client-side-encryption.json	Generated encryption test.
source/​read-write-concern/​tests/​write-concern-errors/​client-bulkWrite.yml	Tests client bulk-write errors on MongoDB 8.0+.
source/​read-write-concern/​tests/​write-concern-errors/​client-bulkWrite.json	Generated client bulk-write test.
source/​read-write-concern/​tests/​write-concern-errors/​bulkWrite.yml	Tests collection bulk-write errors.
source/​read-write-concern/​tests/​write-concern-errors/​bulkWrite.json	Generated collection bulk-write test.
source/​read-write-concern/​tests/​write-concern-errors/​aggregate.yml	Tests aggregation errors with $out and $merge.
source/​read-write-concern/​tests/​write-concern-errors/​aggregate.json	Generated aggregation tests.
source/​read-write-concern/​tests/​README.md	Describes the write concern error suite.
source/​read-write-concern/​read-write-concern.md	Mandates reporting and updates test requirements and changelog.

_{Review effort: Balanced}

[codeowners-service-app]

Assigned GromNaN for team dbx-spec-maintainers-crud because qingyang-hu is out of office.

[kevinAlbs]

A not-yet-well-reviewed C driver draft implementation passes these tests: mongodb/mongo-c-driver#2517

Most of my suggestions are test tweaks and coverage additions. I think the only substantial comment is a wording change to indicate writeConcernError must always be parsed, unless it is a generic runCommand API.

[kevinAlbs]

Suggest testing additional ClientEncryption operations that send write commands: createDataKey, deleteKey, addKeyAltName, and removeKeyAltName. These operations are already referenced in other unified tests, so I expect are already supported by test runners.

[isabelatkinson]

updated

[kevinAlbs]

LGTM. Latest tests pass in C driver implementation locally, and are running in Evergreen.

[BorisDog]

Tests pass in .NET locally.