feat(microservices): add return buffers option for binary data

[Forceres]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Now we can't directly get buffers from redis, so any custom binary formats are broken. Moreover, our redis output has to be json that contradicts to custom binary formats.

What is the new behavior?

We can pass returnBuffers to client options for listening on "messageBuffer" instead of "message" to get directly buffers from redis. createResponseCallback handles jsons as well as binary (but we have to pass custom deserializer to decode id from it)

Does this PR introduce a breaking change?

• Yes
• No

[coveralls]

Pull Request Test Coverage Report for Build 472dd428-2ae6-4d12-bfd5-a48cbbd1c630

Details

• 6 of 9 (66.67%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.03%) to 89.828%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/microservices/client/client-redis.ts	6	9	66.67%

Files with Coverage Reduction	New Missed Lines	%
packages/microservices/client/client-redis.ts	1	79.39%

Totals
Change from base Build bcb7b573-9798-42cb-a347-1d1f9e70592c:	-0.03%
Covered Lines:	7603
Relevant Lines:	8464

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💛 - Coveralls

[kamilmysliwiec]

Could you please add an integration test for this as well?

[Forceres]

Could you please add an integration test for this as well?

Yeah, give me some time.

[Qodo-Free-For-OSS]

Hi, returnBuffers is used as a client option but it is not part of the public RedisOptions / IORedisOptions types, so TypeScript consumers cannot set it without type assertions and won’t discover it via IntelliSense.

Severity: action required | Category: maintainability

How to fix: Add returnBuffers to options types

Agent prompt to fix - you can give this to your LLM of choice:

Issue description

returnBuffers is implemented/used but is not part of the public Redis options typings, so TS users can’t set it cleanly.

Issue Context

RedisOptions.options is ... & IORedisOptions, but IORedisOptions doesn’t include returnBuffers.

Fix Focus Areas

• packages/microservices/external/redis.interface.ts[1-120]
• packages/microservices/interfaces/microservice-configuration.interface.ts[123-137]

Notes

Prefer adding returnBuffers?: boolean to IORedisOptions (since it’s an ioredis option) so it flows through RedisOptions everywhere.

We noticed a couple of other issues in this PR as well - happy to share if helpful.

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Spotted by Qodo code review - free for open-source projects.

[Qodo-Free-For-OSS]

Hi, When returnBuffers is enabled, the Redis subscription handler is attached to messageBuffer, but createResponseCallback() is still typed as receiving buffer: string, reducing type-safety and encouraging incorrect usage.

Severity: remediation recommended | Category: maintainability

How to fix: Widen callback param type

Agent prompt to fix - you can give this to your LLM of choice:

Issue description

createResponseCallback() should accept both string and Buffer payloads because it can be bound to either message or messageBuffer.

Issue Context

When returnBuffers is true, registerReadyListener binds messageBuffer.

Fix Focus Areas

• packages/microservices/client/client-redis.ts[138-155]
• packages/microservices/client/client-redis.ts[231-270]

Notes

Update the signature to (channel: string, buffer: string | Buffer) => Promise<void> and adjust parsing to avoid implicit coercions (e.g., const raw = Buffer.isBuffer(buffer) ? buffer.toString() : buffer).

We noticed a couple of other issues in this PR as well - happy to share if helpful.

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Found by Qodo code review