Demo code for https://github.com/aws/aws-sdk-js-v3/pull/3852

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsSdkErrorHeaderProvider.java

@@ -0,0 +1,8 @@
+package software.amazon.smithy.aws.typescript.codegen;
+
+public class AwsSdkErrorHeaderProvider implements ErrorHeaderProvider {
+    @Override
+    public String getErrorHeader() {
+        return "x-amzn-errortype";
+    }
+}

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/ErrorHeaderProvider.java

@@ -0,0 +1,5 @@
+package software.amazon.smithy.aws.typescript.codegen;
+
+public interface ErrorHeaderProvider {
+    String getErrorHeader();
+}

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/JsonErrorCodeStubGenerator.java

@@ -0,0 +1,9 @@
+package software.amazon.smithy.aws.typescript.codegen;
+
+import software.amazon.smithy.utils.IoUtils;
+
+public class JsonErrorCodeStubGenerator {
+    public static String getStub(final Class<?> c) {
+        return String.format(IoUtils.readUtf8Resource(c, "load-json-error-code-stub.ts"), ResolvedErrorHeaderProvider.getSingletonInstance().getErrorHeader());
+    }
+}

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/JsonRpcProtocolGenerator.java

@@ -84,7 +84,7 @@ public void generateSharedComponents(GenerationContext context) {
 
         TypeScriptWriter writer = context.getWriter();
         writer.addUseImports(getApplicationProtocol().getResponseType());
-        writer.write(IoUtils.readUtf8Resource(getClass(), "load-json-error-code-stub.ts"));
+        writer.write(JsonErrorCodeStubGenerator.getStub(getClass()));
     }
 
     @Override

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/ResolvedErrorHeaderProvider.java

@@ -0,0 +1,22 @@
+package software.amazon.smithy.aws.typescript.codegen;
+
+import java.util.ServiceLoader;
+
+public class ResolvedErrorHeaderProvider implements ErrorHeaderProvider {
+    private static final ErrorHeaderProvider SINGLETON = new ResolvedErrorHeaderProvider();
+
+    final String errorHeader;
+    private ResolvedErrorHeaderProvider() {
+        final ServiceLoader<ErrorHeaderProvider> loader = ServiceLoader.load(ErrorHeaderProvider.class);
+        errorHeader = loader.findFirst().orElse(new AwsSdkErrorHeaderProvider());
+    }
+
+    @Override
+    public String getErrorHeader() {
+        return errorHeader;
+    }
+
+    public static ErrorHeaderProvider getSingletonInstance() {
+        return SINGLETON;
+    }
+}

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/RestJsonProtocolGenerator.java

@@ -83,7 +83,7 @@ public void generateSharedComponents(GenerationContext context) {
 
         TypeScriptWriter writer = context.getWriter();
         writer.addUseImports(getApplicationProtocol().getResponseType());
-        writer.write(IoUtils.readUtf8Resource(getClass(), "load-json-error-code-stub.ts"));
+        writer.write(JsonErrorCodeStubGenerator.getStub(getClass()));
     }
 
     @Override
@@ -93,7 +93,7 @@ protected void writeDefaultInputHeaders(GenerationContext context, OperationShap
 
     @Override
     protected void writeDefaultErrorHeaders(GenerationContext context, StructureShape error) {
-        context.getWriter().write("'x-amzn-errortype': $S,", error.getId().getName());
+        context.getWriter().write("'$L': $S,", ResolvedErrorHeaderProvider.getSingletonInstance().getErrorHeader(), error.getId().getName());
     }
 
     @Override