Possible to define a functionality that allows for custom defaults/generation

[michael-jaquier]

We have a litany of Protobufs. I would like the following to function

let mut rng = rand::thread_rng();
let my_proto: MyProto = MyProto.generate(&mut rng);
let my_proto_but_different: MyProto = MyProto.generate(&mut rng);
/// ... Do work with the proto -> Send it into system for smoke testing/testing purposes

The use case for us/me is the protos we utilize are often highly nested. The quantity of these protos makes it impractical to define some function like

pub fn generate_my_proto(rng: &mut rng) -> MyProto { ... }

Would something like so be acceptable? I believe I could create the necessary functionality behind a feature flag in code generation extending what is already create for Default::default() but would such a feature be accepted? There's no point in writing the code for it if it forces me to fork prost in perpetuity.

[caspermeijn]

I feel like you are looking for the crate Arbitrary[https://docs.rs/arbitrary/latest/arbitrary/] I think you could derive it automatically using prost-build. Let me know how that went, as I am interested in that as well. It would be great if prost-types could derive arbitrary as well. That should be behind a feature flag. Are you willing to contribute that? 20 aug. 2024 15:19:11 Michael Jaquier ***@***.***>:

…

We have a litany of Protobufs. I would like the following to function let mut rng = rand::thread_rng(); let my_proto: MyProto = MyProto.generate(&mut rng); let my_proto_but_different: MyProto = MyProto.generate(&mut rng); /// ... Do work with the proto -> Send it into system for smoke testing/testing purposes The use case for us/me is the protos we utilize are often highly nested. The quantity of these protos makes it impractical to define some function like pub fn generate_my_proto(rng: &mut rng) -> MyProto { ... } Would something like so be acceptable? I believe I could create the necessary functionality behind a feature flag in code generation extending what is already create for *Default::default()* but would such a feature be accepted? There's no point in writing the code for it if it forces me to fork prost in perpetuity. — Reply to this email directly, view it on GitHub[#1131], or unsubscribe[https://github.com/notifications/unsubscribe-auth/AAJZ7OXMHT4MJOHMKVW2OBDZSM64ZAVCNFSM6AAAAABMZ4VWC2VHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZXGA3TKMBSGI]. You are receiving this because you are subscribed to this thread. [Tracking afbeelding][https://github.com/notifications/beacon/AAJZ7OR37CMJ2WDPXDXAUOLZSM64ZA5CNFSM6AAAAABMZ4VWC2WGG33NNVSW45C7OR4XAZNKIRUXGY3VONZWS33OVJRW63LNMVXHIX3JMTHAA27UZY.gif]

[mzabaluev]

Proptest is another library that can help, it provides more flexible generation strategies than Arbitrary, can shrink failure cases, and maintain a record of past regressions. proptest-derive provides the derive macro.