Moya: Is it possible to save or capture Moya responses into stub json ala VCR?

[apollow]

I was wondering if there was a way to automatically capture json responses and put them into JSON. Is there an out of box solution or is one needed to be made?

[sunshinejr]

Hey @apollow. This is a good question. There is no out-of-the-box solution yet (but there is potential for a library). However, I did a demo some time ago to show how to easily save stubs and use them using Moya (and few more), here. This one is kinda old (both Swift/Moya), so you would have to update the syntax, but the idea is there.

Hope it helps!

[SD10]

Kind of similar to #197. I'm not sure if Moya should have a caching layer but maybe this could be extended through a plugin. In v10.0 we're going to review the API around stubbed requests so that would be a good time to look at this further.

[AndrewSB]

@SD10 I'm still pretty bullish on small single purpose libraries, and I think adding caching to Moya would add a lot of complexity and make it harder to reason about the state of program.

Ideal caching in my opinion would sit above Moya, maybe like

let networkProvider = RxMoya<ATarget>()
let diskProvider = SomeDiskProvider()

let cache = ACache(firstPrioritize: diskProvider, thenPrioritize: networkProvider)

cache.giveMeThe(.zen)

What do you think?

[pietrocaselani]

I am using Carlos to cache responses. There is an example of how to add Moya support in this issue
It's similar to Andrew's idea.

[SD10]

@AndrewSB I think I had similiar thoughts:

let moyaProvider = MoyaProvider<SomeTarget>()
let cacheProvider = CacheProvider(provider: moyaProvider)

cacheProvider.request(.zen)

I think a cache at any level of a program increases its complexity/the difficulty to reason about its state. Having this hidden in Moya's internals could increase that difficulty but I believe this is true for any library you don't fully understand internally.

My main concerns are:

• The maintainability of the codebase
• The quality of a caching feature (considering there are other projects devoted to this)
• We have to consider different types of persistence

Moya does one simple thing and it does it incredibly well. If a new feature doesn't match the quality of what we do already it's more clutter than anything useful IMO.

[AndrewSB]

@SD10: Other than making it more visible, what upside do you think there would be in building this cache over using Carlos?

[SD10]

@AndrewSB The only upside is Moya users getting these capabilities by default 🤔 I don't think we can maintain something as robust as Carlos.

I just checked Alamofire because I consider it a good guide considering we lean so heavily on it and are one level above it. It supports basic caching using URLCache. However, I'm not too fond of the auto-purging behavior 😅

[AndrewSB]

I think the capabilities are robust, complicated, and variable enough that we shouldn't prescribe a one-size-fits-all solution to everyone who uses Moya.

I think those who care about caching should configure something that works for them -- whether that be a URLCache, something like PINRemoteImage just to cache images, or Carlos to cache some/all requests -- and all of their caching and expiration policies

[SD10]

@AndrewSB So it seems like we both agree this wouldn't be a valuable addition to Moya's core. Better to let other libraries build Moya plugins.

[stale[bot]]

This issue has been marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[stale[bot]]

This issue has been auto-closed because there hasn't been any activity for at least 37 days. However, we really appreciate your contribution, so thank you for that! 🙏 Also, feel free to open a new issue if you still experience this problem 👍.