Unverified Commit 2c3a4c15 authored by Fahad Zubair's avatar Fahad Zubair Committed by GitHub
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Operations with an event stream member shape must have `ValidationException` (#3814) 

This PR addresses an issue where, if an operation's input includes an
event streaming member, the builder for the operation input or output
may raise a `ConstraintViolation` when `build_enforcing_all_constraints`
is called and the event streaming member field is not set. This occurs
because the member shape is required.

The standard error message that is shown when `ValidationException` is
not attached to an operation is also displayed in this case:

*Operation test#TestOperation takes in input that is constrained
(https://awslabs.github.io/smithy/2.0/spec/constraint-traits.html), and
as such can fail with a validation exception. You must model this
behavior in the operation shape in your model file.*

```smithy
use smithy.framework#ValidationException

operation TestOperation {
    ...
    errors: [..., ValidationException] // <-- Add this.
}
```
Closes: [3813](https://github.com/smithy-lang/smithy-rs/issues/3813

)

---------

Co-authored-by: default avatarFahad Zubair <fahadzub@amazon.com>
parent ce468750

.changelog/7869753.md

0 → 100644
+9 −0
Original line number Diff line number Diff line 
---

applies_to: ["server"]

authors: ["drganjoo"]

references: ["smithy-rs#3813"]

breaking: true

new_feature: false

bug_fix: true

---

Operations with event stream member shapes must include `ValidationException` in the errors list. This is necessary because the member shape is a required field, and the builder for the operation input or output returns a `std::result::Result` with the error set to `crate::model::ValidationExceptionField`.

codegen-core/common-test-models/constraints.smithy

+1 −0
Original line number Diff line number Diff line
@@ -190,6 +190,7 @@ operation StreamingBlobOperation { 
operation EventStreamsOperation {

    input: EventStreamsOperationInputOutput,

    output: EventStreamsOperationInputOutput,

    errors: [ValidationException]

}



structure ConstrainedShapesOperationInputOutput {

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraints.kt

+2 −2
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ import software.amazon.smithy.model.traits.UniqueItemsTrait 
import software.amazon.smithy.rust.codegen.core.smithy.DirectedWalker

import software.amazon.smithy.rust.codegen.core.smithy.traits.SyntheticEventStreamUnionTrait

import software.amazon.smithy.rust.codegen.core.util.expectTrait

import software.amazon.smithy.rust.codegen.core.util.hasEventStreamMember

import software.amazon.smithy.rust.codegen.core.util.hasTrait

import software.amazon.smithy.rust.codegen.core.util.inputShape

import software.amazon.smithy.rust.codegen.core.util.orNull
@@ -190,7 +191,7 @@ fun operationShapesThatMustHaveValidationException( 
        .filter { operationShape ->

            // Walk the shapes reachable via this operation input.

            walker.walkShapes(operationShape.inputShape(model))

                .any { it is SetShape || it is EnumShape || it.hasConstraintTrait() }

                .any { it is SetShape || it is EnumShape || it.hasConstraintTrait() || it.hasEventStreamMember(model) }

        }

        .toSet()

}
@@ -207,7 +208,6 @@ fun validateOperationsWithConstrainedInputHaveValidationExceptionAttached( 
    // `ValidationException` attached in `errors`. https://github.com/smithy-lang/smithy-rs/pull/1199#discussion_r809424783

    // TODO(https://github.com/smithy-lang/smithy-rs/issues/1401): This check will go away once we add support for

    //  `disableDefaultValidation` set to `true`, allowing service owners to map from constraint violations to operation errors.

    val walker = DirectedWalker(model)

    val operationsWithConstrainedInputWithoutValidationExceptionSet =

        operationShapesThatMustHaveValidationException(model, service)

            .filter { !it.errors.contains(validationExceptionShapeId) }

codegen-server/src/test/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ValidateUnsupportedConstraintsAreNotUsedTest.kt

+45 −0
Original line number Diff line number Diff line
@@ -81,6 +81,51 @@ internal class ValidateUnsupportedConstraintsAreNotUsedTest { 
            """.trimIndent()

    }



    @Test

    fun `should detect when event streams are used, even without constraints, as the event member is required`() {

        val model =

            """

            $baseModel

            structure TestInputOutput {

                eventStream: EventStream

            }

            @streaming

            union EventStream {

                message: Message,

                error: Error

            }

            structure Message {

                lengthString: String

            }

            structure Error {

                message: String

            }

            """.asSmithyModel()

        val service = model.lookup<ServiceShape>("test#TestService")

        val validationResult =

            validateOperationsWithConstrainedInputHaveValidationExceptionAttached(

                model,

                service,

                SmithyValidationExceptionConversionGenerator.SHAPE_ID,

            )



        validationResult.messages shouldHaveSize 1



        // Asserts the exact message, to ensure the formatting is appropriate.

        validationResult.messages[0].message shouldBe

            """

            Operation test#TestOperation takes in input that is constrained (https://awslabs.github.io/smithy/2.0/spec/constraint-traits.html), and as such can fail with a validation exception. You must model this behavior in the operation shape in your model file.

            ```smithy

            use smithy.framework#ValidationException



            operation TestOperation {

                ...

                errors: [..., ValidationException] // <-- Add this.

            }

            ```

            """.trimIndent()

    }



    private val constraintTraitOnStreamingBlobShapeModel =

        """

        $baseModel