Upgrade Smithy to 1.50.0

[ysaito1001]

Motivation and Context

This PR upgrades Smithy to 1.50.0. The majority of the changes follow TODO added in #3690. Other than that, a few adjustments needed to be made:

• for the client
  • added two failing tests RestJsonClientPopulatesDefaultValuesInInput and RestJsonClientUsesExplicitlyProvidedMemberValuesOverDefaults to known failing tests for the same reason here
  • added one broken test (i.e. the upstream test definition is incorrect but our implementation is correct) to known broken tests per (smithy#2341, smithy-rs#3726)
• for the server
  • removed rest-xml-extras.smithy since RestXmlMustSupportParametersInContentType is now available upstream Smithy 1.50.0
  • added the following to known failing tests (since the awsJson1_0 counterparts are already in the list, but we need the server team to verify this assumption & provide additional TODO comments if necessary)
    • RestJsonServerPopulatesDefaultsWhenMissingInRequestBody
    • RestJsonServerPopulatesDefaultsInResponseWhenMissingInParams,
    • RestJsonServerPopulatesNestedDefaultValuesWhenMissingInInResponseParams

Testing

Existing tests in CI

---

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

[github-actions]

A new generated diff is ready to view.

• No codegen difference in the AWS SDK
• Client Test (ignoring whitespace)
• Server Test (ignoring whitespace)
• Server Test Python (ignoring whitespace)
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.

[github-actions]

A new generated diff is ready to view.

• No codegen difference in the AWS SDK
• Client Test (ignoring whitespace)
• Server Test (ignoring whitespace)
• Server Test Python (ignoring whitespace)
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.

[github-actions]

A new generated diff is ready to view.

• No codegen difference in the AWS SDK
• Client Test (ignoring whitespace)
• Server Test (ignoring whitespace)
• Server Test Python (ignoring whitespace)
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.

[david-perez]

RestJsonServerPopulatesDefaultsWhenMissingInRequestBody fails because defaultNullDocument has a null default, so the hasNonNullDefault check here:

smithy-rs/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ServerBuilderGenerator.kt

Line 537 in 9af72f5

if (member.hasNonNullDefault()) {

is false and so aws_smithy_types::Document::Null is not used by the instantiator.

But even if we improved the check and special-cased document member shapes, there's an additional problem: the same check is used by Smithy itself here when determining whether the structure member should be optional or not. Since the node for the @default value of the member shape is null, Smithy says the structure member should be optional. But the generated code for default value setting expects the member to be non-Optional, since there's a default value.

In general, this begs the question of whether a required (non-Optional) document shape makes sense at all. The user can always set it to aws_smithy_types::Document::Null and convey the same semantics as if shape were nullable and None had been set for it. To belabor the point, consider this model:

structure OperationInput {
    @required
    document: Document
}

This gets generated in Rust as:

struct OperationInput {
    document: aws_smithy_types::Document
}

The user can instantiate this as:

let op_input = OperationInput::builder()
    .document(aws_smithy_types::Document::Null)
    .build();

Which will get serialized on the wire as { document: null } or { }, depending on whether the protocol serializes nulls or not, respectively. Either way, we're allowing the user to not provide a value for a required member shape, violating the model.

[ysaito1001]

Thanks for the detailed explanation! Moved the test to the bottom of the list and added a link to this discussion for more context.

[github-actions]

A new generated diff is ready to view.

• No codegen difference in the AWS SDK
• Client Test (ignoring whitespace)
• Server Test (ignoring whitespace)
• Server Test Python (ignoring whitespace)
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.

[github-actions]

A new generated diff is ready to view.

• No codegen difference in the AWS SDK
• Client Test (ignoring whitespace)
• Server Test (ignoring whitespace)
• Server Test Python (ignoring whitespace)
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.

[github-actions]

A new generated diff is ready to view.

• No codegen difference in the AWS SDK
• Client Test (ignoring whitespace)
• Server Test (ignoring whitespace)
• Server Test Python (ignoring whitespace)
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.

[github-actions]

A new generated diff is ready to view.

• No codegen difference in the AWS SDK
• Client Test (ignoring whitespace)
• Server Test (ignoring whitespace)
• Server Test Python (ignoring whitespace)
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.