Unverified Commit 7b54e540 authored by greenwoodcm's avatar greenwoodcm Committed by GitHub
Browse files

add `RuleBuilder::then_compute_output` (#4299) 



this allows the developer to compute a mocked output using content from
the input.

## Motivation and Context
Some richer use cases for stubbing/mocking require computing a stubbed
output using data from the input, for instance stubbing a method that
returns the item that was put.

## Description
Add a new method to `RuleBuilder` that allows for providing a function
that computes the output. That function takes in a reference to the
input as an argument. I'm not sure how this works with the mutable
inputs like streamed bytes, but seems to work for the simple stuff.

## Testing
added a simple unit test

----

_By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice._

---------

Co-authored-by: default avatarAaron Todd <aajtodd@users.noreply.github.com>
parent 9f495a45

.changelog/1757712519.md

0 → 100644
+19 −0
Original line number Diff line number Diff line 
---

applies_to: ["client"]

authors: ["greenwoodcm"]

references: ["smithy-rs#4299"]

breaking: false

new_feature: true

bug_fix: false

---

Added a new `then_compute_output` to `aws-smithy-mocks` rule builder that allows using the input type when computing a mocked response, e.g. 

```rs

// Return a computed output based on the input

let compute_rule = mock!(Client::get_object)

    .then_compute_output(|req| {

        let key = req.key().unwrap_or("unknown");

        GetObjectOutput::builder()

            .body(ByteStream::from_static(format!("content for {}", key).as_bytes()))

            .build()

    });

```

aws/sdk/integration-tests/s3/tests/mocks.rs

+33 −0
Original line number Diff line number Diff line
@@ -89,6 +89,39 @@ async fn test_mock_client() { 
    assert_eq!(err.code(), Some("InvalidAccessKey"));

}



#[tokio::test]

async fn test_mock_client_compute() {

    let s3_computed = mock!(aws_sdk_s3::Client::get_object)

        .match_requests(|inp| {

            inp.bucket() == Some("test-bucket") && inp.key() == Some("correct-key")

        })

        .then_compute_output(|input| {

            let content =

                format!("{}.{}", input.bucket().unwrap(), input.key().unwrap()).into_bytes();

            GetObjectOutput::builder()

                .body(ByteStream::from(content))

                .build()

        });



    let s3 = mock_client!(aws_sdk_s3, &[&s3_computed]);



    let data = s3

        .get_object()

        .bucket("test-bucket")

        .key("correct-key")

        .send()

        .await

        .expect("success response")

        .body

        .collect()

        .await

        .expect("successful read")

        .to_vec();



    assert_eq!(data, b"test-bucket.correct-key");

    assert_eq!(s3_computed.num_calls(), 1);

}



#[tokio::test]

async fn test_mock_client_sequence() {

    let rule = mock!(aws_sdk_s3::Client::get_object)

rust-runtime/Cargo.lock

+1 −1
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@@ -560,7 +560,7 @@ dependencies = [ 


[[package]]

name = "aws-smithy-mocks"

version = "0.1.1"

version = "0.1.2"

dependencies = [

 "aws-smithy-async",

 "aws-smithy-http-client",

rust-runtime/aws-smithy-mocks/Cargo.toml

+2 −2
Original line number Diff line number Diff line 
[package]

name = "aws-smithy-mocks"

version = "0.1.1"

version = "0.1.2"

authors = ["AWS Rust SDK Team <aws-sdk-rust@amazon.com>"]

description = "Testing utilities for smithy-rs generated clients"

edition = "2021"
@@ -9,7 +9,7 @@ repository = "https://github.com/smithy-lang/smithy-rs" 


[dependencies]

aws-smithy-types = { path = "../aws-smithy-types" }

aws-smithy-runtime-api = { path = "../aws-smithy-runtime-api", features = ["client", "http-1x"] }

aws-smithy-runtime-api = { path = "../aws-smithy-runtime-api", features = ["client", "http-1x", "test-util"] }

aws-smithy-http-client = { path = "../aws-smithy-http-client", features = ["test-util"] }

http = "1"

rust-runtime/aws-smithy-mocks/README.md

+9 −0
Original line number Diff line number Diff line
@@ -83,6 +83,15 @@ let http_rule = mock!(Client::get_object) 
        StatusCode::try_from(503).unwrap(),

        SdkBody::from("service unavailable")

    ));



// Return a computed output based on the input

let compute_rule = mock!(Client::get_object)

    .then_compute_output(|req| {

        let key = req.key().unwrap_or("unknown");

        GetObjectOutput::builder()

            .body(ByteStream::from_static(format!("content for {}", key).as_bytes()))

            .build()

    });

```



### Response Sequences