DRIVERS-3439 Remove pre-MongoDB 4.2 references from specs and tests by jyemin · Pull Request #1929 · mongodb/specifications

jyemin · 2026-04-29T19:23:29Z

Summary

Removes all spec tests and prose gated on MongoDB server versions < 4.2, now that 4.2 is the minimum supported server version.

26 YAML spec test files deleted (CRUD client/server error tests, CLM pre-42 connection ID tests, CSE maxWireVersion tests, SDAM pre-42 error tests + template)
28 individual tests removed from mixed files (dots_and_dollars pre-3.6 tests, hint-unacknowledged pre-4.2 tests, dead copydb* tests in redacted-commands)
18 spec documents simplified — removed version-conditional language for SDAM, collation, auth, transactions, retryable-writes, read-write-concern, find_getmore, OP_MSG, change-streams, unified-test-format, index-management, compression, enumerate-collections, enumerate-databases, causal-consistency, handshake, decimal128
generate-error-tests.py cleaned up: removed create_pre_42_tests() function

JSON files for modified YAML tests were regenerated via make and committed separately. Commits will be squashed before merge.

DRIVERS-3439

GromNaN · 2026-05-13T16:03:01Z

Should you drop everything specific to maxWireVersion < 9? They are not relevant for server >= 4.4

specifications/source/collation/collation.md

Line 10 in c250bf7

As of MongoDB server version 3.4 (maxWireVersion 5), a collation option is supported by the query system for matching
specifications/source/message/OP_MSG.md

Line 20 in c250bf7

`OP_MSG` is only available in MongoDB 3.6 (`maxWireVersion >= 6`) and later. MongoDB drivers MUST perform the MongoDB

specifications/source/transactions/transactions.md

Lines 298 to 299 in c250bf7

    
           A deployment does not support transactions when the deployment does not support sessions, or maxWireVersion < 7, or the 
        
           maxWireVersion < 8 and the topology type is Sharded, see

specifications/source/mongodb-handshake/handshake.md

Lines 102 to 104 in c250bf7

    
           if reply["maxWireVersion"] >= 6: 
        
               # Use OP_MSG for all future commands, including authentication. 
        
               conn.supports_op_msg = True

specifications/source/retryable-reads/retryable-reads.md

Lines 90 to 92 in c250bf7

    
           Drivers MUST verify server eligibility by ensuring that `maxWireVersion` is at least 6 because retryable reads require a 
        
           MongoDB 3.6 standalone, replica set or shard cluster, MongoDB 3.6 server wire version is 6 as defined in the 
        
           [Server Wire version and Feature List specification](../wireversion-featurelist/wireversion-featurelist.md).

...

jyemin · 2026-06-09T15:17:51Z

Should you drop everything specific to maxWireVersion < 9? They are not relevant for server >= 4.4

I don't want to remove 4.2 references until all drivers remove support for 4.2. Definitely a good followup though, once that happens.

Copilot

Pull request overview

This PR updates the MongoDB driver specifications and associated unified/legacy test suites to reflect MongoDB 4.2 as the minimum supported server version, removing pre-4.2 (and some earlier) conditional prose and test coverage.

Changes:

Removed pre-4.2-gated YAML/JSON spec tests (notably SDAM error templates/tests, CLM connection-id tests, CSFLE maxWireVersion tests, and various CRUD “client/server error on older server” cases).
Simplified multiple spec documents by deleting version-conditional language that is no longer relevant with a 4.2+ baseline.
Updated SDAM error test generator to stop producing pre-4.2 test variants.

Reviewed changes

Copilot reviewed 95 out of 95 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
source/unified-test-format/unified-test-format.md	Simplifies deprecated topology guidance by removing version gating.
source/transactions/transactions.md	Removes pre-4.2-era constraints; updates transaction eligibility text and other prose.
source/server-discovery-and-monitoring/tests/errors/pre-42.yml.template	Deletes pre-4.2 SDAM error test template.
source/server-discovery-and-monitoring/tests/errors/pre-42-ShutdownInProgress.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-ShutdownInProgress.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/pre-42-PrimarySteppedDown.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-PrimarySteppedDown.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/pre-42-NotWritablePrimary.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-NotWritablePrimary.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/pre-42-NotPrimaryOrSecondary.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-NotPrimaryOrSecondary.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/pre-42-NotPrimaryNoSecondaryOk.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-NotPrimaryNoSecondaryOk.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/pre-42-LegacyNotPrimary.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-LegacyNotPrimary.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/pre-42-InterruptedDueToReplStateChange.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-InterruptedDueToReplStateChange.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/pre-42-InterruptedAtShutdown.yml	Deletes pre-4.2 SDAM error test.
source/server-discovery-and-monitoring/tests/errors/pre-42-InterruptedAtShutdown.json	Deletes generated JSON for the removed pre-4.2 SDAM test.
source/server-discovery-and-monitoring/tests/errors/generate-error-tests.py	Removes pre-4.2 test generation path.
source/server-discovery-and-monitoring/server-discovery-and-monitoring.md	Removes pre-4.2 pool-clearing behavior language.
source/server-discovery-and-monitoring/server-discovery-and-monitoring-summary.md	Aligns SDAM summary with 4.2+ behavior (no pool clear).
source/retryable-writes/retryable-writes.md	Removes older-version gating and simplifies unsupported-operation prose.
source/read-write-concern/read-write-concern.md	Removes aggregate-with-write-stage readConcern pre-4.2 carveout.
source/mongodb-handshake/handshake.md	Removes 3.4-specific wording to reflect current baseline.
source/index-management/index-management.md	Removes “new in MongoDB X.Y” phrasing for index option docs.
source/find_getmore_killcursors_commands/find_getmore_killcursors_commands.md	Drops pre-4.2 exhaust behavior rows from tables.
source/enumerate-databases/enumerate-databases.md	Removes historical version introduction notes for listDatabases options.
source/enumerate-collections/enumerate-collections.md	Removes historical version introduction notes for listCollections options.
source/crud/tests/unified/updateOne-hint-unacknowledged.yml	Removes pre-4.2 test cases; reanchors shared filter/update values.
source/crud/tests/unified/updateOne-hint-unacknowledged.json	Regenerated JSON reflecting removal of pre-4.2 cases.
source/crud/tests/unified/updateOne-hint-serverError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/updateOne-hint-serverError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/updateOne-hint-clientError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/updateOne-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/updateMany-hint-unacknowledged.yml	Removes pre-4.2 test cases; reanchors shared filter/update values.
source/crud/tests/unified/updateMany-hint-unacknowledged.json	Regenerated JSON reflecting removal of pre-4.2 cases.
source/crud/tests/unified/updateMany-hint-serverError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/updateMany-hint-serverError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/updateMany-hint-clientError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/updateMany-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/replaceOne-hint-unacknowledged.yml	Removes pre-4.2 test cases; reanchors shared filter/replacement values.
source/crud/tests/unified/replaceOne-hint-unacknowledged.json	Regenerated JSON reflecting removal of pre-4.2 cases.
source/crud/tests/unified/replaceOne-dots_and_dollars.yml	Removes pre-3.6 cases from dots-and-dollars replaceOne tests.
source/crud/tests/unified/replaceOne-dots_and_dollars.json	Regenerated JSON reflecting removal of pre-3.6 cases.
source/crud/tests/unified/insertOne-dots_and_dollars.yml	Removes pre-3.6 case from dots-and-dollars insertOne tests.
source/crud/tests/unified/insertOne-dots_and_dollars.json	Regenerated JSON reflecting removal of pre-3.6 case.
source/crud/tests/unified/findOneAndUpdate-hint-clientError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/findOneAndUpdate-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/findOneAndReplace-hint-clientError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/findOneAndReplace-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/findOneAndReplace-dots_and_dollars.yml	Removes pre-3.6 cases from dots-and-dollars findOneAndReplace tests.
source/crud/tests/unified/findOneAndReplace-dots_and_dollars.json	Regenerated JSON reflecting removal of pre-3.6 cases.
source/crud/tests/unified/findOneAndDelete-hint-clientError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/findOneAndDelete-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/find-allowdiskuse-clientError.yml	Deletes pre-3.2-only unified test.
source/crud/tests/unified/find-allowdiskuse-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/deleteOne-hint-clientError.yml	Deletes pre-3.4-only unified test.
source/crud/tests/unified/deleteOne-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/deleteMany-hint-clientError.yml	Deletes pre-3.4-only unified test.
source/crud/tests/unified/deleteMany-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/bulkWrite-updateOne-hint-unacknowledged.yml	Removes pre-4.2 bulkWrite hint cases; reanchors shared values.
source/crud/tests/unified/bulkWrite-updateOne-hint-unacknowledged.json	Regenerated JSON reflecting removal of pre-4.2 cases.
source/crud/tests/unified/bulkWrite-updateMany-hint-unacknowledged.yml	Removes pre-4.2 bulkWrite hint cases; reanchors shared values.
source/crud/tests/unified/bulkWrite-updateMany-hint-unacknowledged.json	Regenerated JSON reflecting removal of pre-4.2 cases.
source/crud/tests/unified/bulkWrite-update-hint-serverError.yml	Deletes pre-4.2-only unified test.
source/crud/tests/unified/bulkWrite-update-hint-serverError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/bulkWrite-update-hint-clientError.yml	Deletes pre-3.4-only unified test.
source/crud/tests/unified/bulkWrite-update-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/bulkWrite-replaceOne-hint-unacknowledged.yml	Removes pre-4.2 bulkWrite replaceOne hint cases; reanchors shared values.
source/crud/tests/unified/bulkWrite-replaceOne-hint-unacknowledged.json	Regenerated JSON reflecting removal of pre-4.2 cases.
source/crud/tests/unified/bulkWrite-replaceOne-dots_and_dollars.yml	Removes pre-3.6 cases from dots-and-dollars bulkWrite replaceOne tests.
source/crud/tests/unified/bulkWrite-replaceOne-dots_and_dollars.json	Regenerated JSON reflecting removal of pre-3.6 cases.
source/crud/tests/unified/bulkWrite-delete-hint-clientError.yml	Deletes pre-3.4-only unified test.
source/crud/tests/unified/bulkWrite-delete-hint-clientError.json	Deletes generated JSON for removed unified test.
source/crud/tests/unified/bulkWrite-arrayFilters-clientError.yml	Deletes pre-3.6-only unified test.
source/crud/tests/unified/bulkWrite-arrayFilters-clientError.json	Deletes generated JSON for removed unified test.
source/compression/OP_COMPRESSED.md	Removes pre-4.2 historical notes and updates compressor support wording.
source/command-logging-and-monitoring/tests/monitoring/redacted-commands.yml	Removes tests for commands removed pre-4.2 (copydb*).
source/command-logging-and-monitoring/tests/monitoring/redacted-commands.json	Regenerated JSON reflecting removal of copydb* cases.
source/command-logging-and-monitoring/tests/monitoring/pre-42-server-connection-id.yml	Deletes pre-4.2-only connection-id unified test.
source/command-logging-and-monitoring/tests/monitoring/pre-42-server-connection-id.json	Deletes generated JSON for removed connection-id test.
source/command-logging-and-monitoring/tests/logging/redacted-commands.yml	Removes copydb* logging redaction cases.
source/command-logging-and-monitoring/tests/logging/redacted-commands.json	Regenerated JSON reflecting removal of copydb* cases.
source/command-logging-and-monitoring/tests/logging/pre-42-server-connection-id.yml	Deletes pre-4.2-only connection-id logging test.
source/command-logging-and-monitoring/tests/logging/pre-42-server-connection-id.json	Deletes generated JSON for removed connection-id logging test.
source/collation/collation.md	Removes pre-3.4/low-wire-version compatibility text now irrelevant to 4.2+.
source/client-side-encryption/tests/unified/maxWireVersion.yml	Deletes pre-4.2-only CSFLE maxWireVersion unified test.
source/client-side-encryption/tests/unified/maxWireVersion.json	Deletes generated JSON for removed CSFLE test.
source/client-side-encryption/tests/legacy/maxWireVersion.yml	Deletes pre-4.2-only CSFLE legacy-format test.
source/client-side-encryption/tests/legacy/maxWireVersion.json	Deletes generated JSON for removed legacy CSFLE test.
source/change-streams/change-streams.md	Removes 4.0.7-specific notes around postBatchResumeToken.
source/causal-consistency/causal-consistency.md	Removes 3.6+ phrasing now irrelevant to 4.2+ baseline.
source/bson-decimal128/decimal128.md	Removes “MongoDB 3.4 introduces” phrasing; keeps generic Decimal128 requirements.
source/auth/auth.md	Removes MONGODB-CR references and other pre-4.2 era version notes; simplifies defaults/mechanism sections.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

 startTransaction SHOULD report an error if the driver can detect that transactions are not supported by the deployment.
-A deployment does not support transactions when the deployment does not support sessions, or maxWireVersion < 7, or the
-maxWireVersion < 8 and the topology type is Sharded, see
+A deployment does not support transactions when the deployment does not support sessions, see
 [How to Tell Whether a Connection Supports Sessions](../sessions/driver-sessions.md#how-to-tell-whether-a-connection-supports-sessions).
-Note that checking the maxWireVersion does not guarantee that the deployment supports transactions, for example a
-MongoDB 4.0 replica set using MMAPv1 will report maxWireVersion 7 but does not support transactions. In this case,
-Drivers rely on the deployment to report an error when a transaction is started.



 Any command that marks the beginning of a transaction MAY include a `readConcern` argument with an optional `level` and
-`afterClusterTime` fields. Read concern level 'local', 'majority', and 'snapshot' are all supported, although they will
-all have the same behavior as "snapshot" in MongoDB 4.0. To support causal consistency, if `readConcern`
-`afterClusterTime` is specified, then the server will ensure that the transaction’s read timestamp is after the
-`afterClusterTime`.
+`afterClusterTime` fields. Read concern level ‘local’, ‘majority’, and ‘snapshot’ are all supported. To support causal
+consistency, if `readConcern` `afterClusterTime` is specified, then the server will ensure that the transaction’s read
+timestamp is after the `afterClusterTime`.


+The only supported retryable write commands within a transaction are `commitTransaction` and `abortTransaction`.
+Therefore drivers MUST NOT retry write commands within transactions even when `retryWrites` has been set to true on the
+`MongoClient`. In addition, drivers MUST NOT add the `RetryableWriteError` label to any error that occurs during a write
+command within a transaction (excepting `commitTransation` and `abortTransaction`), even when `retryWrites` has been set
+to true on the `MongoClient`.


 - username

-    SHOULD NOT be provided for MongoDB 3.4+ MUST be specified and non-zero length for MongoDB prior to 3.4
+    SHOULD NOT be provided



NoahStapp

A few other sections I saw that were missed:

crud.md has many comments in pseudocode and interfaces that refer to unsupported server versions.
transactions.md still has references to 4.0, such as "Starting in MongoDB 4.0, any command error may include a top level "errorLabels" field".
The "Gossipping with mixed server versions" section in driver-sessions.md is no longer relevant now that all supported server versions support $clusterTime.
The "Requirements for Retryable Reads" section in retryable-reads.md contains content only for server version < 3.6.
The "timeoutMS cannot be overridden for startSession calls" section in client-side-operations-timeout.md references 3.6.
The if isShutdown(code) or (error was from <4.2) pseudocode in server-discovery-and-monitoring.md.
auth.md still has references to older versions, such as in the "Multi-credential drivers" section.
The "Connection handshake" section in handshake.md.

NoahStapp · 2026-06-09T15:34:16Z

-
 #### Conversation

 1. Send `authenticate` command (MongoDB 3.4+)


Suggested change

1. Send `authenticate` command (MongoDB 3.4+)

1. Send `authenticate` command

NoahStapp · 2026-06-09T15:41:28Z

 ]
 ```

 Server version between 2.7.6 (inclusive) and 4.0 (exclusive) do not support the `nameOnly` option for the


This entire range is no longer supported and so this clarification should be removed.

NoahStapp · 2026-06-09T15:43:34Z

 An algorithm is specified for inspecting error codes (MongoDB 3.6+) and falling back to parsing error messages when
 error codes are unavailable (MongoDB 3.4 and earlier). When the client sees such an error it knows its topology view is


Suggested change

An algorithm is specified for inspecting error codes (MongoDB 3.6+) and falling back to parsing error messages when

error codes are unavailable (MongoDB 3.4 and earlier). When the client sees such an error it knows its topology view is

An algorithm is specified for inspecting error codes. When the client sees such an error it knows its topology view is

NoahStapp · 2026-06-09T15:52:34Z


 If the handshake response includes a `saslSupportedMechs` field, then drivers MUST use the contents of that field to
 select a default mechanism as described later. If the command succeeds and the response does not include a
 `saslSupportedMechs` field, then drivers MUST use the legacy default mechanism rules for servers older than 4.0.


4.0 is no longer supported, this distinction is not needed.

jyemin force-pushed the DRIVERS-3439 branch from f71321b to e302c62 Compare June 9, 2026 15:02

DRIVERS-3439 remove pre-4.2 test files

02d2d3d

jyemin force-pushed the DRIVERS-3439 branch from e302c62 to a664f58 Compare June 9, 2026 15:10

jyemin requested a review from NoahStapp June 9, 2026 15:14

jyemin requested a review from GromNaN June 9, 2026 15:18

jyemin marked this pull request as ready for review June 9, 2026 15:18

jyemin requested review from a team as code owners June 9, 2026 15:18

jyemin requested review from Copilot and mana2-bot June 9, 2026 15:18

Copilot started reviewing on behalf of jyemin June 9, 2026 15:19 View session

Copilot AI reviewed Jun 9, 2026

View reviewed changes

DRIVERS-3439 simplify spec prose for 4.2+ minimum

bedcf50

jyemin force-pushed the DRIVERS-3439 branch from a664f58 to bedcf50 Compare June 9, 2026 15:35

NoahStapp requested changes Jun 9, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

DRIVERS-3439 Remove pre-MongoDB 4.2 references from specs and tests#1929

DRIVERS-3439 Remove pre-MongoDB 4.2 references from specs and tests#1929
jyemin wants to merge 2 commits into
mongodb:masterfrom
jyemin:DRIVERS-3439

jyemin commented Apr 29, 2026 •

edited

Loading

Uh oh!

GromNaN commented May 13, 2026 •

edited

Loading

Uh oh!

jyemin commented Jun 9, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

NoahStapp left a comment •

edited

Loading

Uh oh!

NoahStapp Jun 9, 2026

Uh oh!

NoahStapp Jun 9, 2026

Uh oh!

NoahStapp Jun 9, 2026

Uh oh!

NoahStapp Jun 9, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants


		#### Conversation

		1. Send `authenticate` command (MongoDB 3.4+)

	1. Send `authenticate` command (MongoDB 3.4+)
	1. Send `authenticate` command

		An algorithm is specified for inspecting error codes (MongoDB 3.6+) and falling back to parsing error messages when
		error codes are unavailable (MongoDB 3.4 and earlier). When the client sees such an error it knows its topology view is

Conversation

jyemin commented Apr 29, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Uh oh!

GromNaN commented May 13, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

jyemin commented Jun 9, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

NoahStapp left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

NoahStapp Jun 9, 2026

Choose a reason for hiding this comment

Uh oh!

NoahStapp Jun 9, 2026

Choose a reason for hiding this comment

Uh oh!

NoahStapp Jun 9, 2026

Choose a reason for hiding this comment

Uh oh!

NoahStapp Jun 9, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

jyemin commented Apr 29, 2026 •

edited

Loading

GromNaN commented May 13, 2026 •

edited

Loading

NoahStapp left a comment •

edited

Loading