Bump smithy version to 1.52 (#3887)

## Motivation and Context
<!--- Why is this change required? What problem does it solve? -->
<!--- If it fixes an open issue, please link to the issue here -->
Bumping smithy to 1.52 for an `httpChecksum` trait bugfix

A few fixes had to be made to protocol tests for this release:
* Update document to initialize as empty `{}` instead of null
* Update our header serialization to serialize present but empty headers
to `""` (Note that this change does not apply to server header
serialization)
* Add `accept: application/cbor` header to add rpcV2Cbor requests
* Skip two broken tests. These tests were fixed in
smithy-lang/smithy#2423 and that change was
included in the 1.52 release notes, but the actual change did not make
it into the build artifact. The changes should make it into the 1.52.1
release in the next few days:
smithy-lang/smithy#2428

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

codegen-client-test/model/error-correction-nullability-test.smithy

@@ -102,7 +102,7 @@ apply SayHello @httpResponseTests([{
                                              listValue: [],
                                              mapValue: {},
                                              doubleListValue: []
-                                             document: null
+                                             document: {}
                                              nested: { a: "" }
                                          },
                                          code: 200,

codegen-client/src/main/kotlin/software/amazon/smithy/rust/codegen/client/smithy/generators/http/RequestBindingGenerator.kt

@@ -91,7 +91,7 @@ class RequestBindingGenerator(
      */
     fun renderUpdateHttpBuilder(implBlockWriter: RustWriter) {
         uriBase(implBlockWriter)
-        val addHeadersFn = httpBindingGenerator.generateAddHeadersFn(operationShape)
+        val addHeadersFn = httpBindingGenerator.generateAddHeadersFn(operationShape, serializeEmptyHeaders = true)
         val hasQuery = uriQuery(implBlockWriter)
         Attribute.AllowClippyUnnecessaryWraps.render(implBlockWriter)
         implBlockWriter.rustBlockTemplate(

codegen-client/src/main/kotlin/software/amazon/smithy/rust/codegen/client/smithy/generators/protocol/ClientProtocolTestGenerator.kt

@@ -5,7 +5,6 @@
 
 package software.amazon.smithy.rust.codegen.client.smithy.generators.protocol
 
-import software.amazon.smithy.model.node.NumberNode
 import software.amazon.smithy.model.shapes.DoubleShape
 import software.amazon.smithy.model.shapes.FloatShape
 import software.amazon.smithy.model.shapes.OperationShape
@@ -28,6 +27,7 @@ import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.Broke
 import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.FailingTest
 import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.ProtocolSupport
 import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.ProtocolTestGenerator
+import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.ServiceShapeId
 import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.ServiceShapeId.AWS_JSON_10
 import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.ServiceShapeId.REST_JSON
 import software.amazon.smithy.rust.codegen.core.smithy.generators.protocol.ServiceShapeId.RPC_V2_CBOR
@@ -83,20 +83,54 @@ class ClientProtocolTestGenerator(
             )
 
         private val BrokenTests:
-            Set<BrokenTest> = setOf()
+            Set<BrokenTest> =
+            // The two tests below were fixed in "https://github.com/smithy-lang/smithy/pull/2423", but the fixes didn't make
+            // it into the build artifact for 1.52
+            setOf(
+                BrokenTest.ResponseTest(
+                    ServiceShapeId.REST_XML,
+                    "NestedXmlMapWithXmlNameDeserializes",
+                    howToFixItFn = ::fixRestXMLInvalidRootNodeResponse,
+                    inAtLeast = setOf("1.52.0"),
+                    trackedIn =
+                        setOf(
+                            "https://github.com/smithy-lang/smithy/pull/2423",
+                        ),
+                ),
+                BrokenTest.RequestTest(
+                    ServiceShapeId.REST_XML,
+                    "NestedXmlMapWithXmlNameSerializes",
+                    howToFixItFn = ::fixRestXMLInvalidRootNodeRequest,
+                    inAtLeast = setOf("1.52.0"),
+                    trackedIn =
+                        setOf(
+                            "https://github.com/smithy-lang/smithy/pull/2423",
+                        ),
+                ),
+            )
 
-        private fun fixRestJsonClientIgnoresDefaultValuesIfMemberValuesArePresentInResponse(
-            testCase: TestCase.ResponseTest,
-        ): TestCase.ResponseTest {
-            val fixedParams =
-                testCase.testCase.params.toBuilder().withMember("defaultTimestamp", NumberNode.from(2)).build()
+        private fun fixRestXMLInvalidRootNodeResponse(testCase: TestCase.ResponseTest): TestCase.ResponseTest {
+            val fixedBody =
+                testCase.testCase.body.get()
+                    .replace("NestedXmlMapWithXmlNameResponse", "NestedXmlMapWithXmlNameInputOutput")
             return TestCase.ResponseTest(
                 testCase.testCase.toBuilder()
-                    .params(fixedParams)
+                    .body(fixedBody)
                     .build(),
                 testCase.targetShape,
             )
         }
+
+        private fun fixRestXMLInvalidRootNodeRequest(testCase: TestCase.RequestTest): TestCase.RequestTest {
+            val fixedBody =
+                testCase.testCase.body.get()
+                    .replace("NestedXmlMapWithXmlNameRequest", "NestedXmlMapWithXmlNameInputOutput")
+            return TestCase.RequestTest(
+                testCase.testCase.toBuilder()
+                    .body(fixedBody)
+                    .build(),
+            )
+        }
     }
 
     override val appliesTo: AppliesTo

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/smithy/generators/http/HttpBindingGenerator.kt

@@ -30,6 +30,7 @@ import software.amazon.smithy.rust.codegen.core.rustlang.RustType
 import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.rustlang.Writable
 import software.amazon.smithy.rust.codegen.core.rustlang.asOptional
+import software.amazon.smithy.rust.codegen.core.rustlang.conditionalBlock
 import software.amazon.smithy.rust.codegen.core.rustlang.qualifiedName
 import software.amazon.smithy.rust.codegen.core.rustlang.render
 import software.amazon.smithy.rust.codegen.core.rustlang.rust
@@ -491,6 +492,7 @@ class HttpBindingGenerator(
     fun generateAddHeadersFn(
         shape: Shape,
         httpMessageType: HttpMessageType = HttpMessageType.REQUEST,
+        serializeEmptyHeaders: Boolean = false,
     ): RuntimeType? {
         val (headerBindings, prefixHeaderBinding) =
             when (httpMessageType) {
@@ -538,7 +540,7 @@ class HttpBindingGenerator(
                 """,
                 *codegenScope,
             ) {
-                headerBindings.forEach { httpBinding -> renderHeaders(httpBinding) }
+                headerBindings.forEach { httpBinding -> renderHeaders(httpBinding, serializeEmptyHeaders) }
                 if (prefixHeaderBinding != null) {
                     renderPrefixHeader(prefixHeaderBinding)
                 }
@@ -547,7 +549,10 @@ class HttpBindingGenerator(
         }
     }
 
-    private fun RustWriter.renderHeaders(httpBinding: HttpBinding) {
+    private fun RustWriter.renderHeaders(
+        httpBinding: HttpBinding,
+        serializeEmptyHeaders: Boolean,
+    ) {
         check(httpBinding.location == HttpLocation.HEADER)
         val memberShape = httpBinding.member
         val targetShape = model.expectShape(memberShape.target)
@@ -585,6 +590,7 @@ class HttpBindingGenerator(
                     targetShape,
                     timestampFormat,
                     renderErrorMessage,
+                    serializeEmptyHeaders,
                 )
             } else {
                 renderHeaderValue(
@@ -596,6 +602,7 @@ class HttpBindingGenerator(
                     renderErrorMessage,
                     serializeIfDefault = memberSymbol.isOptional(),
                     memberShape,
+                    serializeEmptyHeaders,
                 )
             }
         }
@@ -608,6 +615,7 @@ class HttpBindingGenerator(
         shape: CollectionShape,
         timestampFormat: TimestampFormatTrait.Format,
         renderErrorMessage: (String) -> Writable,
+        serializeEmptyHeaders: Boolean,
     ) {
         val loopVariable = ValueExpression.Reference(safeName("inner"))
         val context = HeaderValueSerializationContext(value, shape)
@@ -617,17 +625,29 @@ class HttpBindingGenerator(
             )(this)
         }
 
-        rustBlock("for ${loopVariable.name} in ${context.valueExpression.asRef()}") {
-            this.renderHeaderValue(
-                headerName,
-                loopVariable,
-                model.expectShape(shape.member.target),
-                isMultiValuedHeader = true,
-                timestampFormat,
-                renderErrorMessage,
-                serializeIfDefault = true,
-                shape.member,
-            )
+        // Conditionally wrap the header generation in a block that handles empty header values if
+        // `serializeEmptyHeaders` is true
+        conditionalBlock(
+            """
+            // Empty vec in header is serialized as an empty string
+            if ${context.valueExpression.name}.is_empty() {
+                builder = builder.header("$headerName", "");
+            } else {""",
+            "}", conditional = serializeEmptyHeaders,
+        ) {
+            rustBlock("for ${loopVariable.name} in ${context.valueExpression.asRef()}") {
+                this.renderHeaderValue(
+                    headerName,
+                    loopVariable,
+                    model.expectShape(shape.member.target),
+                    isMultiValuedHeader = true,
+                    timestampFormat,
+                    renderErrorMessage,
+                    serializeIfDefault = true,
+                    shape.member,
+                    serializeEmptyHeaders,
+                )
+            }
         }
     }
 
@@ -647,6 +667,7 @@ class HttpBindingGenerator(
         renderErrorMessage: (String) -> Writable,
         serializeIfDefault: Boolean,
         memberShape: MemberShape,
+        serializeEmptyHeaders: Boolean,
     ) {
         val context = HeaderValueSerializationContext(value, shape)
         for (customization in customizations) {
@@ -669,20 +690,24 @@ class HttpBindingGenerator(
                     isMultiValuedHeader = isMultiValuedHeader,
                 )
             val safeName = safeName("formatted")
-            rustTemplate(
-                """
-                let $safeName = $formatted;
-                if !$safeName.is_empty() {
+
+            // If `serializeEmptyHeaders` is false we wrap header serialization in a `!foo.is_empty()` check and skip
+            // serialization if the header value is empty
+            rust("let $safeName = $formatted;")
+            conditionalBlock("if !$safeName.is_empty() {", "}", conditional = !serializeEmptyHeaders) {
+                rustTemplate(
+                    """
                     let header_value = $safeName;
                     let header_value: #{HeaderValue} = header_value.parse().map_err(|err| {
                         #{invalid_field_error:W}
                     })?;
                     builder = builder.header("$headerName", header_value);
-                }
-                """,
-                "HeaderValue" to RuntimeType.Http.resolve("HeaderValue"),
-                "invalid_field_error" to renderErrorMessage("header_value"),
-            )
+
+                    """,
+                    "HeaderValue" to RuntimeType.Http.resolve("HeaderValue"),
+                    "invalid_field_error" to renderErrorMessage("header_value"),
+                )
+            }
         }
         if (serializeIfDefault) {
             block(context.valueExpression)

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/smithy/protocols/RpcV2Cbor.kt

@@ -111,8 +111,9 @@ open class RpcV2Cbor(val codegenContext: CodegenContext) : Protocol {
     // using floating point seconds from the epoch.
     override val defaultTimestampFormat: TimestampFormatTrait.Format = TimestampFormatTrait.Format.EPOCH_SECONDS
 
+    // The accept header is required by the spec (and by all of the protocol tests)
     override fun additionalRequestHeaders(operationShape: OperationShape): List<Pair<String, String>> =
-        listOf("smithy-protocol" to "rpc-v2-cbor")
+        listOf("smithy-protocol" to "rpc-v2-cbor", "accept" to "application/cbor")
 
     override fun additionalResponseHeaders(operationShape: OperationShape): List<Pair<String, String>> =
         listOf("smithy-protocol" to "rpc-v2-cbor")

gradle.properties

@@ -15,7 +15,7 @@ smithy.rs.runtime.crate.unstable.version=0.60.6
 kotlin.code.style=official
 # codegen
 smithyGradlePluginVersion=0.9.0
-smithyVersion=1.51.0
+smithyVersion=1.52.0
 allowLocalDeps=false
 # kotlin
 kotlinVersion=1.9.20