Add more client re-exports (#2437)

* Add more client re-exports

This commit adds more client re-exports proposed in
#1759.
Specifically, it re-exports the following types:
- `aws_smithy_http::body::SdkBody`
- `aws_smithy_http::byte_stream::error::Error`
- `aws_smithy_http::operation::{Request, Response}`

* Update CHANGELOG.next.toml

---------

Co-authored-by: Yuki Saito <awsaito@amazon.com>

CHANGELOG.next.toml

@@ -251,3 +251,15 @@ message = "Fix `FilterByOperationName` plugin. This previous caused services wit
 references = ["smithy-rs#2441"]
 meta = { "breaking" = false, "tada" = false, "bug" = true, "target" = "server" }
 author = "hlbarber"
+
+[[aws-sdk-rust]]
+message = "Add more client re-exports. Specifically, it re-exports `aws_smithy_http::body::SdkBody`, `aws_smithy_http::byte_stream::error::Error`, and `aws_smithy_http::operation::{Request, Response}`."
+references = ["smithy-rs#2437", "aws-sdk-rust#600"]
+meta = { "breaking" = false, "tada" = false, "bug" = false }
+author = "ysaito1001"
+
+[[smithy-rs]]
+message = "Add more client re-exports. Specifically, it re-exports `aws_smithy_http::body::SdkBody`, `aws_smithy_http::byte_stream::error::Error`, and `aws_smithy_http::operation::{Request, Response}`."
+references = ["smithy-rs#2437", "aws-sdk-rust#600"]
+meta = { "breaking" = false, "tada" = false, "bug" = false, "target" = "client" }
+author = "ysaito1001"

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

@@ -33,10 +33,14 @@ class CustomizableOperationGenerator(
             rustTemplate(
                 """
                 pub use #{Operation};
+                pub use #{Request};
+                pub use #{Response};
                 pub use #{ClassifyRetry};
                 pub use #{RetryKind};
                 """,
                 "Operation" to smithyHttp.resolve("operation::Operation"),
+                "Request" to smithyHttp.resolve("operation::Request"),
+                "Response" to smithyHttp.resolve("operation::Response"),
                 "ClassifyRetry" to smithyHttp.resolve("retry::ClassifyRetry"),
                 "RetryKind" to smithyTypes.resolve("retry::RetryKind"),
             )

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/smithy/customizations/SmithyTypesPubUseExtra.kt

@@ -21,6 +21,7 @@ import software.amazon.smithy.rust.codegen.core.util.letIf
 private data class PubUseType(
     val type: RuntimeType,
     val shouldExport: (Model) -> Boolean,
+    val alias: String? = null,
 )
 
 /** Returns true if the model has normal streaming operations (excluding event streams) */
@@ -48,7 +49,10 @@ private fun hasBlobs(model: Model): Boolean = structUnionMembersMatchPredicate(m
 private fun hasDateTimes(model: Model): Boolean = structUnionMembersMatchPredicate(model, Shape::isTimestampShape)
 
 /** Returns a list of types that should be re-exported for the given model */
-internal fun pubUseTypes(codegenContext: CodegenContext, model: Model): List<RuntimeType> {
+internal fun pubUseTypes(codegenContext: CodegenContext, model: Model): List<RuntimeType> =
+    pubUseTypesThatShouldBeExported(codegenContext, model).map { it.type }
+
+private fun pubUseTypesThatShouldBeExported(codegenContext: CodegenContext, model: Model): List<PubUseType> {
     val runtimeConfig = codegenContext.runtimeConfig
     return (
         listOf(
@@ -58,16 +62,25 @@ internal fun pubUseTypes(codegenContext: CodegenContext, model: Model): List<Run
             listOf(
                 PubUseType(http.resolve("byte_stream::ByteStream"), ::hasStreamingOperations),
                 PubUseType(http.resolve("byte_stream::AggregatedBytes"), ::hasStreamingOperations),
+                PubUseType(http.resolve("byte_stream::error::Error"), ::hasStreamingOperations, "ByteStreamError"),
+                PubUseType(http.resolve("body::SdkBody"), ::hasStreamingOperations),
             )
         }
-        ).filter { pubUseType -> pubUseType.shouldExport(model) }.map { it.type }
+        ).filter { pubUseType -> pubUseType.shouldExport(model) }
 }
 
 /** Adds re-export statements for Smithy primitives */
 fun pubUseSmithyPrimitives(codegenContext: CodegenContext, model: Model): Writable = writable {
-    val types = pubUseTypes(codegenContext, model)
+    val types = pubUseTypesThatShouldBeExported(codegenContext, model)
     if (types.isNotEmpty()) {
-        types.forEach { type -> rust("pub use #T;", type) }
+        types.forEach {
+            val useStatement = if (it.alias == null) {
+                "pub use #T;"
+            } else {
+                "pub use #T as ${it.alias};"
+            }
+            rust(useStatement, it.type)
+        }
     }
 }
 
@@ -77,14 +90,15 @@ fun pubUseSmithyErrorTypes(codegenContext: CodegenContext): Writable = writable
     val reexports = listOf(
         listOf(
             RuntimeType.smithyHttp(runtimeConfig).let { http ->
-                PubUseType(http.resolve("result::SdkError")) { true }
+                PubUseType(http.resolve("result::SdkError"), { _ -> true })
             },
         ),
         RuntimeType.smithyTypes(runtimeConfig).let { types ->
-            listOf(PubUseType(types.resolve("error::display::DisplayErrorContext")) { true })
+            listOf(PubUseType(types.resolve("error::display::DisplayErrorContext"), { _ -> true }))
                 // Only re-export `ProvideErrorMetadata` for clients
                 .letIf(codegenContext.target == CodegenTarget.CLIENT) { list ->
-                    list + listOf(PubUseType(types.resolve("error::metadata::ProvideErrorMetadata")) { true })
+                    list +
+                        listOf(PubUseType(types.resolve("error::metadata::ProvideErrorMetadata"), { _ -> true }))
                 }
         },
     ).flatten()