Add contextIdentifier: UUID? parameter to perform(mutation:...) method on ApolloClient

[marsn-ext]

Hello!

Feature request

I'd like to add an optional parameter on ApolloClient's perform(mutation:...) method for the contextIdentiifer: UUID? of the request. This parameter is already present in the client's fetch(query:...) method, but unfortunately missing from perform(mutation:...).

Motivation

I'm interested in a similar functionality described by this other issue #2283. In short, I need to add certain headers to specific request instances. Using the contextIdentifier helps with this, but this option is not available on mutations.

In the short term, adding the parameter should offer this flexibility for mutations while the H2 networking stack overhaul comes through (as mentioned in the other issue).

Proposed solution

Add optional contextIdentifier: UUID? to ApolloClient's perform(mutation:...) method.

Outstanding Questions

The only potential conflict this PR could add is if integrators have created their own implementation against ApolloClientProtocol. In those cases, they will have to repair the conformance since the change is a breaking change on the protocol.

[marsn-ext]

I'm happy to draft up a PR for this if this change proposal sounds reasonable 👍

[calvincestari]

Hi @marsn-ext, apologies for taking so long to get back to you. At first glance I'm not opposed to adding contextIdentifier to the perform(mutation: .. ) protocol signature. It seems you're aware of the networking stack being the next target for development so if this provides short-term gain without severe downsides I'm fine with it.

@AnthonyMDev - do you have any objection to this addition?

[vincentisambart]

It seems this can be closed as the parameter has been added to 1.9.1:

Feature/ContextIdentifier for the mutate queries (apollographql/apollo-ios-dev#281): Mutation operations can now be given a context identifier to be used later in the request.

[calvincestari]

Thanks @vincentisambart, I'd long forgotten that we had an issue for that PR change.

[github-actions]

Do you have any feedback for the maintainers? Please tell us by taking a one-minute survey. Your responses will help us understand Apollo iOS usage and allow us to serve you better.