* Runtime API versioning
Related to issue #11577
Add support for multiple versions of a Runtime API. The purpose is to
have one main version of the API, which is considered stable and
multiple unstable (aka staging) ones.
How it works
===========
Some methods of the API trait can be tagged with `#[api_version(N)]`
attribute where N is version number bigger than the main one. Let's call
them **staging methods** for brevity.
The implementor of the API decides which version to implement.
Example (from https://github.com/paritytech/substrate/issues/11577#issuecomment-1145347025):
```
decl_runtime_apis! {
#{api_version(10)]
trait Test {
fn something() -> Vec<u8>;
#[api_version(11)]
fn new_cool_function() -> u32;
}
}
```
```
impl_runtime_apis! {
#[api_version(11)]
impl Test for Runtime {
fn something() -> Vec<u8> { vec![1, 2, 3] }
fn new_cool_function() -> u32 {
10
}
}
}
```
Version safety checks (currently not implemented)
=================================================
By default in the API trait all staging methods has got default
implementation calling `unimplemented!()`. This is a problem because if
the developer wants to implement version 11 in the example above and
forgets to add `fn new_cool_function()` in `impl_runtime_apis!` the
runtime will crash when the function is executed.
Ideally a compilation error should be generated in such cases.
TODOs
=====
Things not working well at the moment:
[ ] Version safety check
[ ] Integration tests of `primitives/api` are messed up a bit. More
specifically `primitives/api/test/tests/decl_and_impl.rs`
[ ] Integration test covering the new functionality.
[ ] Some duplicated code
* Update primitives/api/proc-macro/src/impl_runtime_apis.rs
Code review feedback and formatting
Co-authored-by: asynchronous rob <rphmeier@gmail.com>
* Code review feedback
Applying suggestions from @bkchr
* fmt
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Code review feedback
* dummy trait -> versioned trait
* Implement only versioned traits (not compiling)
* Remove native API calls (still not compiling)
* fmt
* Fix compilation
* Comments
* Remove unused code
* Remove native runtime tests
* Remove unused code
* Fix UI tests
* Code review feedback
* Code review feedback
* attribute_names -> common
* Rework `append_api_version`
* Code review feedback
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Code review feedback
* Code review feedback
* Code review feedback
* Use type alias for the default trait - doesn't compile
* Fixes
* Better error for `method_api_ver < trait_api_version`
* fmt
* Rework how we call runtime functions
* Update UI tests
* Fix warnings
* Fix doctests
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
* Fix formatting and small compilation errors
* Update primitives/api/proc-macro/src/impl_runtime_apis.rs
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: asynchronous rob <rphmeier@gmail.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: Bastian Köcher <info@kchr.de>
Przemek Rzad