[AIP 131] Should Get request message be defined in the same file of the service?

[mingzhi]

In the example, should we enforce that the GetBookRequest message must be defined in the same file of GetBook method?

If no, it is very hard to ask the API linter to enforce the rules on the request message. Image that GetBook message is defined in the get_book_message.proto, and the RPC method is defined in get_book_service.proto: now consider that get_book_message.proto is checked and committed first, but no issue related to this AIP is found; then get_book_service.proto is checked, it will produce linting errors on the get_book_message.proto, which is undesired.

[lukesneeringer]

AIP-191 already mandates this.

[bshi]

@lukesneeringer I'm not sure that AIP-191 mandates it explicitly? There is a bullet under "File layout" that says

Components should be in the following order
...

• The RPC request and response message definitions, in the same order of the corresponding methods. Each request message must precede its corresponding response message (if any).

...

It is implied Request/Response messages must be in the same file but I can't find anything mandating or even recommending that these messages be in the same file as the method definitions.

[lukesneeringer]

I would recommend adding that mandate to AIP-151. They should definitely be in the same file, particularly for import hygiene in generated code.

[lukesneeringer]

Err sorry I meant AIP-191.