lambda_http: Make extension methods available for http::request::Parts

[dcormier]

Closes #606.

Adds extension methods to http::request::Parts and http::Extensions, which allows the methods to be used after calling Request::into_parts() in addition to on the request itself. Closes #606, which has more detailed info.

By submitting this pull request

• I confirm that my contribution is made under the terms of the Apache 2.0 license.
• I confirm that I've made a best effort attempt to update all relevant documentation.

[calavera]

Thanks for this contribution. It looks like there are some breaking changes. I think they need some more consideration.

[dcormier]

Yes, there are quite a few breaking changes. More than you've commented on. I've detailed them in #606. I just want to make sure you're aware.

[calavera]

These two breaking changes need to be reverted too:

fn request_context(&self) -> RequestContext becomes
fn request_context(&self) -> Option<&RequestContext>
fn lambda_context(&self) -> Context becomes
fn lambda_context(&self) -> Option<&Context>

[dcormier]

Done.

[calavera]

I just noticed that the module's name also changed, from RequestExt to ExtensionsExt. Please revert that, we don't want to make such major breaking changes without good reasons. That can erode customer trust.

[dcormier]

It's been broken into two traits. ExtensionsExt and RequestExt. The goal of this PR being to expose the additional methods even if the Request has been broken into parts.

pub trait ExtensionsExt {
    fn raw_http_path(&self) -> &str;
    fn with_raw_http_path<S>(self, path: S) -> Self
    where
        S: Into<String>;

    fn query_string_parameters(&self) -> QueryMap;
    fn query_string_parameters_ref(&self) -> Option<&QueryMap>;
    fn with_query_string_parameters<Q>(self, parameters: Q) -> Self
    where
        Q: Into<QueryMap>;

    fn path_parameters(&self) -> QueryMap;
    fn path_parameters_ref(&self) -> Option<&QueryMap>;
    fn with_path_parameters<P>(self, parameters: P) -> Self
    where
        P: Into<QueryMap>;

    fn stage_variables(&self) -> QueryMap;
    fn stage_variables_ref(&self) -> Option<&QueryMap>;
    #[cfg(test)]
    fn with_stage_variables<V>(self, variables: V) -> Self
    where
        V: Into<QueryMap>;

    fn request_context(&self) -> RequestContext;
    fn request_context_ref(&self) -> Option<&RequestContext>;
    fn with_request_context(self, context: RequestContext) -> Self;

    fn lambda_context(&self) -> Context;
    fn lambda_context_ref(&self) -> Option<&Context>;
    fn with_lambda_context(self, context: Context) -> Self;
}

impl ExtensionsExt for http::Extensions { ... }
impl ExtensionsExt for http::Parts { ... }
impl<B> ExtensionsExt for http::Request<B> { ... }

pub trait RequestExt {
    fn payload<D>(&self) -> Result<Option<D>, PayloadError>
    where
        for<'de> D: Deserialize<'de>;
}

impl RequestExt for lambda_http::Request { ... }

I can rename ExtensionsExt to RequestExt. Should current RequestExt in this PR become, say, RequestPayload?

[calavera]

I can rename ExtensionsExt to RequestExt. Should current RequestExt in this PR become, say, RequestPayload?

RequestExt and RequestPayloadExt work for me.

[calavera]

Thanks for working on this! LGTM

[dcormier]

Thank you for reviewing it.