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builder-provider-api case-study: Change plain-URL links into md auto-… #17

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12 changes: 6 additions & 6 deletions evaluation/case-studies/builder-provider-api.md
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Expand Up @@ -108,15 +108,15 @@ impl DefaultCredentialsChain {

This extra trait is an implementation detail that is not in the public-facing, API so it can be migrated away when support for AFIDT is introduced.

A full builder pattern example is implemented here: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=8daf7b2d5236e581f78d2c09310d09ac
A full builder pattern example is implemented here: <https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=8daf7b2d5236e581f78d2c09310d09ac>

## Send bounds

One limitation with the proposed async version of `ProvideCredentials` is the lack of a `Send` bound on the future returned by `ProvideCredentials`. This bound is enforced by the pre-AFIT version of this trait, so any futures using the builder will not be `Send` after AFIT migration.

To fix this, we could use a return type bound[^2] on the `with_custom_credential_source` builder method:

[^2]: https://smallcultfollowing.com/babysteps/blog/2023/02/13/return-type-notation-send-bounds-part-2/
[^2]: <https://smallcultfollowing.com/babysteps/blog/2023/02/13/return-type-notation-send-bounds-part-2/>

```rust
impl DefaultCredentialsChain {
Expand Down Expand Up @@ -157,10 +157,10 @@ impl<T: async(Send) ProvideCredentials> ProvideCredentialsDyn for T {
## Usages

The SDK uses this same idiom several times:
* `ProvideCredentials`: https://docs.rs/aws-credential-types/0.54.1/aws_credential_types/provider/trait.ProvideCredentials.html
* `AsyncSleep`: https://docs.rs/aws-smithy-async/0.54.3/aws_smithy_async/rt/sleep/trait.AsyncSleep.html
* `ProvideRegion`: https://docs.rs/aws-config/0.54.1/aws_config/meta/region/trait.ProvideRegion.html
* `ProvideCredentials`: <https://docs.rs/aws-credential-types/0.54.1/aws_credential_types/provider/trait.ProvideCredentials.html>
* `AsyncSleep`: <https://docs.rs/aws-smithy-async/0.54.3/aws_smithy_async/rt/sleep/trait.AsyncSleep.html>
* `ProvideRegion`: <https://docs.rs/aws-config/0.54.1/aws_config/meta/region/trait.ProvideRegion.html>

## Future improvements

With AFIDT, we can drop the `ProvideCredentialsDyn` trait and just use `Box<dyn ProvideCredentials>` as is. Refactoring the API to use AFIDT is a totally internal-facing change.
With AFIDT, we can drop the `ProvideCredentialsDyn` trait and just use `Box<dyn ProvideCredentials>` as is. Refactoring the API to use AFIDT is a totally internal-facing change.