revert SdkStream type in SymbolVisitor, add to command generator

Author: AllanZhengYP

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/CodegenUtils.java

@@ -117,20 +117,22 @@ static List<MemberShape> getBlobStreamingMembers(Model model, StructureShape sha
         return shape.getAllMembers().values().stream()
                 .filter(memberShape -> {
                     // Streaming blobs need to have their types modified
-                    // See `writeStreamingMemberType`
+                    // See `writeStreamingCommandTypeToSer`
                     Shape target = model.expectShape(memberShape.getTarget());
                     return target.isBlobShape() && target.hasTrait(StreamingTrait.class);
                 })
                 .collect(Collectors.toList());
     }
 
     /**
-     * Ease the input streaming member restriction so that users don't need to construct a stream every time.
-     * This type decoration is allowed in Smithy because it makes input type more permissive than output type
-     * for the same member.
+     * Generate the type of the command output of server sdk or the input of the client sdk given the streaming blob
+     * member of the shape. The generated type eases the streaming member requirement so that users don't need to
+     * construct a stream every time.
+     * This type decoration is allowed in Smithy because it makes, for the same member, the type to be serialized is
+     * more permissive than the type to be deserialized.
      * Refer here for more rationales: https://github.com/aws/aws-sdk-js-v3/issues/843
      */
-    static void writeStreamingMemberType(
+    static void writeStreamingCommandTypeToSer(
             TypeScriptWriter writer,
             Symbol containerSymbol,
             String typeName,
@@ -148,6 +150,38 @@ static void writeStreamingMemberType(
         writer.write("export interface $1L extends $1LType {}", typeName);
     }
 
+    /**
+     * Generate the type of the command input of server sdk or the output of the client sdk given the streaming blob
+     * member of the shape. The type marks the streaming blob member to contain the utility methods to transform the
+     * stream to string, buffer or WHATWG stream API.
+     */
+    static void writeStreamingCommandTypeFromDeser(
+            TypeScriptWriter writer,
+            Symbol containerSymbol,
+            String typeName,
+            MemberShape streamingMember,
+            TypeScriptSettings settings
+    ) {
+        String memberName = streamingMember.getMemberName();
+        String optionalSuffix = streamingMember.isRequired() ? "" : "?";
+        boolean isClientSdk = settings.generateClient();
+        if (isClientSdk) {
+            writer.addImport("MetadataBearer", "__MetadataBearer", TypeScriptDependency.AWS_SDK_TYPES.packageName);
+        }
+        String metadataBearerType = isClientSdk ? "__MetadataBearer & " : "";
+        writer.addImport("SdkStream", "__SdkStream", TypeScriptDependency.AWS_SDK_TYPES.packageName);
+        writer.openBlock("type $LType = $LOmit<$T, $S> & {", "};",
+                typeName, metadataBearerType, containerSymbol, memberName, () -> {
+                        writer.writeDocs(String.format("For *`%1$s[\"%2$s\"]`*, see {@link %1$s.%2$s}.",
+                                containerSymbol.getName(), memberName));
+                        writer.write("$1L$2L: __SdkStream<Required<$3T>[$1S]>;", memberName, optionalSuffix,
+                                containerSymbol);
+        });
+        writer.writeDocs(String.format("This interface extends from `%1$s` interface. There are more parameters than"
+                + " `%2$s` defined in {@link %1$s}", containerSymbol.getName(), memberName));
+        writer.write("export interface $1L extends $1LType {}", typeName);
+    }
+
     /**
      * Returns the list of function parameter key-value pairs to be written for
      * provided parameters map.

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/CommandGenerator.java

@@ -16,7 +16,8 @@
 package software.amazon.smithy.typescript.codegen;
 
 import static software.amazon.smithy.typescript.codegen.CodegenUtils.getBlobStreamingMembers;
-import static software.amazon.smithy.typescript.codegen.CodegenUtils.writeStreamingMemberType;
+import static software.amazon.smithy.typescript.codegen.CodegenUtils.writeStreamingCommandTypeFromDeser;
+import static software.amazon.smithy.typescript.codegen.CodegenUtils.writeStreamingCommandTypeToSer;
 
 import java.nio.file.Paths;
 import java.util.List;
@@ -246,7 +247,8 @@ private void writeInputType(String typeName, Optional<StructureShape> inputShape
             if (blobStreamingMembers.isEmpty()) {
                 writer.write("export interface $L extends $T {}", typeName, symbolProvider.toSymbol(input));
             } else {
-                writeStreamingMemberType(writer, symbolProvider.toSymbol(input), typeName, blobStreamingMembers.get(0));
+                writeStreamingCommandTypeToSer(writer, symbolProvider.toSymbol(input), typeName,
+                        blobStreamingMembers.get(0));
             }
         } else {
             // If the input is non-existent, then use an empty object.
@@ -259,8 +261,15 @@ private void writeOutputType(String typeName, Optional<StructureShape> outputSha
         // to a defined output shape.
         writer.addImport("MetadataBearer", "__MetadataBearer", TypeScriptDependency.AWS_SDK_TYPES.packageName);
         if (outputShape.isPresent()) {
-            writer.write("export interface $L extends $T, __MetadataBearer {}",
-                    typeName, symbolProvider.toSymbol(outputShape.get()));
+            StructureShape output = outputShape.get();
+            List<MemberShape> blobStreamingMembers = getBlobStreamingMembers(model, output);
+            if (blobStreamingMembers.isEmpty()) {
+                writer.write("export interface $L extends $T, __MetadataBearer {}",
+                        typeName, symbolProvider.toSymbol(outputShape.get()));
+            } else {
+                writeStreamingCommandTypeFromDeser(writer, symbolProvider.toSymbol(output), typeName,
+                        blobStreamingMembers.get(0), settings);
+            }
         } else {
             writer.write("export interface $L extends __MetadataBearer {}", typeName);
         }

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/ServerCommandGenerator.java

@@ -16,7 +16,7 @@
 package software.amazon.smithy.typescript.codegen;
 
 import static software.amazon.smithy.typescript.codegen.CodegenUtils.getBlobStreamingMembers;
-import static software.amazon.smithy.typescript.codegen.CodegenUtils.writeStreamingMemberType;
+import static software.amazon.smithy.typescript.codegen.CodegenUtils.writeStreamingCommandTypeFromDeser;
 
 import java.nio.file.Paths;
 import java.util.Collections;
@@ -98,15 +98,15 @@ private void addInputAndOutputTypes() {
         writer.write("");
     }
 
-    // TODO: Flip these so that metadata is attached to input and streaming customization is attached to output.
     private void writeInputType(String typeName, Optional<StructureShape> inputShape) {
         if (inputShape.isPresent()) {
             StructureShape input = inputShape.get();
             List<MemberShape> blobStreamingMembers = getBlobStreamingMembers(model, input);
             if (blobStreamingMembers.isEmpty()) {
                 writer.write("export interface $L extends $T {}", typeName, symbolProvider.toSymbol(input));
             } else {
-                writeStreamingMemberType(writer, symbolProvider.toSymbol(input), typeName, blobStreamingMembers.get(0));
+                writeStreamingCommandTypeFromDeser(writer, symbolProvider.toSymbol(input), typeName,
+                        blobStreamingMembers.get(0), settings);
             }
             renderNamespace(typeName, input);
         } else {
@@ -134,6 +134,7 @@ private void renderNamespace(String typeName, StructureShape input) {
 
     private void writeOutputType(String typeName, Optional<StructureShape> outputShape) {
         if (outputShape.isPresent()) {
+            //TODO: refer to writeStreamingCommandTypeToSer when streaming is supported.
             writer.write("export interface $L extends $T {}",
                     typeName, symbolProvider.toSymbol(outputShape.get()));
         } else {

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/SymbolVisitor.java

@@ -138,11 +138,9 @@ public String toMemberName(MemberShape shape) {
     @Override
     public Symbol blobShape(BlobShape shape) {
         if (shape.hasTrait(StreamingTrait.class)) {
-            // Note: `Readable` and `SdkStream` needs an import and a dependency.
-            return createSymbolBuilder(shape, "SdkStream<Readable | ReadableStream | Blob>", null)
+            // Note: `Readable` needs an import and a dependency.
+            return createSymbolBuilder(shape, "Readable | ReadableStream | Blob", null)
                     .addReference(Symbol.builder().name("Readable").namespace("stream", "/").build())
-                    .addReference(Symbol.builder().name("SdkStream").namespace(
-                            TypeScriptDependency.AWS_SDK_TYPES.packageName, "/").build())
                     .build();
         }
 

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java

@@ -2301,8 +2301,11 @@ private HttpBinding readPayload(
 
         // Handle streaming shapes differently.
         if (target.hasTrait(StreamingTrait.class)) {
-            // If payload is streaming, return low-level stream with the stream utility functions mixin.
-            writer.write("const data: any = context.sdkStreamMixin(output.body);");
+            writer.write("const data: any = output.body;");
+            // If payload is streaming blob, return low-level stream with the stream utility functions mixin.
+            if (target instanceof BlobShape) {
+                writer.write("context.sdkStreamMixin(data);");
+            }
         } else if (target instanceof BlobShape) {
             // If payload is non-streaming Blob, only need to collect stream to binary data (Uint8Array).
             writer.write("const data: any = await collectBody(output.body, context);");