Add RetryableTrait support for Errors (#183)

* Add $retryable to Error is RetryableTrait present

* Write HttpProtocolGeneratorUtils.writeRetryableTrait

* Add tests for RetryableTrait

* Remove formatting introduced by editor.formatOnSave in VSCode

* Call writeRetryableTrait from StructureGenerator

Author: trivikr

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

@@ -23,6 +23,7 @@
 import software.amazon.smithy.model.Model;
 import software.amazon.smithy.model.shapes.StructureShape;
 import software.amazon.smithy.model.traits.ErrorTrait;
+import software.amazon.smithy.typescript.codegen.integration.HttpProtocolGeneratorUtils;
 
 /**
  * Generates normal structures and error structures.
@@ -158,6 +159,7 @@ private void renderErrorStructure() {
         writer.openBlock("export interface $L extends $L {", symbol.getName(), extendsFrom);
         writer.write("name: $S;", shape.getId().getName());
         writer.write("$$fault: $S;", errorTrait.getValue());
+        HttpProtocolGeneratorUtils.writeRetryableTrait(writer, shape, ";");
         StructuredMemberWriter structuredMemberWriter = new StructuredMemberWriter(
                 model, symbolProvider, shape.getAllMembers().values());
         structuredMemberWriter.writeMembers(writer, shape);

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

@@ -912,6 +912,7 @@ private void generateErrorDeserializer(GenerationContext context, StructureShape
             writer.openBlock("const contents: $T = {", "};", errorSymbol, () -> {
                 writer.write("name: $S,", error.getId().getName());
                 writer.write("$$fault: $S,", error.getTrait(ErrorTrait.class).get().getValue());
+                HttpProtocolGeneratorUtils.writeRetryableTrait(writer, error, ",");
                 writer.write("$$metadata: deserializeMetadata($L),", outputName);
                 // Set all the members to undefined to meet type constraints.
                 new TreeMap<>(error.getAllMembers())

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

@@ -35,6 +35,7 @@
 import software.amazon.smithy.model.shapes.StructureShape;
 import software.amazon.smithy.model.traits.EndpointTrait;
 import software.amazon.smithy.model.traits.MediaTypeTrait;
+import software.amazon.smithy.model.traits.RetryableTrait;
 import software.amazon.smithy.model.traits.TimestampFormatTrait.Format;
 import software.amazon.smithy.typescript.codegen.CodegenUtils;
 import software.amazon.smithy.typescript.codegen.TypeScriptDependency;
@@ -241,6 +242,25 @@ static void generateHttpBindingUtils(GenerationContext context) {
         writer.write(IoUtils.readUtf8Resource(HttpProtocolGeneratorUtils.class, "http-binding-utils.ts"));
     }
 
+    /**
+     * Writes $retryable key for error if it contains RetryableTrait.
+     *
+     * @param writer The code writer.
+     * @param error The error to write retryableTrait for.
+     * @param separator The string to be used after emitting key-value pair for retryableTrait.
+     */
+    public static void writeRetryableTrait(TypeScriptWriter writer, StructureShape error, String separator) {
+        Optional<RetryableTrait> retryableTrait = error.getTrait(RetryableTrait.class);
+        if (retryableTrait.isPresent()) {
+            String textAfterBlock = String.format("}%s", separator);
+            writer.openBlock("$$retryable: {", textAfterBlock, () -> {
+                if (retryableTrait.get().getThrottling()) {
+                    writer.write("throttling: true,");
+                }
+            });
+        }
+    }
+
     /**
      * Writes a function used to dispatch to the proper error deserializer
      * for each error that the operation can return. The generated function

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

@@ -379,6 +379,7 @@ private void generateErrorDeserializer(GenerationContext context, StructureShape
             writer.openBlock("const contents: $T = {", "};", errorSymbol, () -> {
                 writer.write("name: $S,", error.getId().getName());
                 writer.write("$$fault: $S,", error.getTrait(ErrorTrait.class).get().getValue());
+                HttpProtocolGeneratorUtils.writeRetryableTrait(writer, error, ",");
                 writer.write("$$metadata: deserializeMetadata($L),", outputReference);
                 writer.write("...deserialized,");
             });

smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/StructureGeneratorTest.java

@@ -43,6 +43,29 @@ public void properlyGeneratesRequiredMessageMemberOfException() {
                                   + "}");
     }
 
+    @Test
+    public void generatesEmptyRetryableTrait() {
+        testErrorStructureCodegen("error-test-retryable.smithy",
+                                  "export interface Err extends __SmithyException, $MetadataBearer {\n"
+                                  + "  name: \"Err\";\n"
+                                  + "  $fault: \"client\";\n"
+                                  + "  $retryable: {\n"
+                                  + "  };\n"
+                                  + "}");
+    }
+
+    @Test
+    public void generatesRetryableTraitWithThrottling() {
+        testErrorStructureCodegen("error-test-retryable-throttling.smithy",
+                                  "export interface Err extends __SmithyException, $MetadataBearer {\n"
+                                  + "  name: \"Err\";\n"
+                                  + "  $fault: \"client\";\n"
+                                  + "  $retryable: {\n"
+                                  + "    throttling: true,\n"
+                                  + "  };\n"
+                                  + "}");
+    }
+
     @Test
     public void filtersSensitiveSimpleShape() {
         testStructureCodegen("test-sensitive-simple-shape.smithy",

smithy-typescript-codegen/src/test/resources/software/amazon/smithy/typescript/codegen/error-test-retryable-throttling.smithy

@@ -0,0 +1,13 @@
+namespace smithy.example
+
+@protocols([{name: "aws.rest-json-1.1"}])
+service Example {
+    version: "1.0.0",
+    operations: [DoSomething]
+}
+
+operation DoSomething() errors [Err]
+
+@error("client")
+@retryable(throttling: true)
+structure Err {}

smithy-typescript-codegen/src/test/resources/software/amazon/smithy/typescript/codegen/error-test-retryable.smithy

@@ -0,0 +1,13 @@
+namespace smithy.example
+
+@protocols([{name: "aws.rest-json-1.1"}])
+service Example {
+    version: "1.0.0",
+    operations: [DoSomething]
+}
+
+operation DoSomething() errors [Err]
+
+@error("client")
+@retryable
+structure Err {}