feat(clients): fallback to status code for unmodeled errors (#3752)

* chore(codegen): parseErrorCode returns optional string

* feat(clients): fallback to status code for unmodeled errors

Author: AllanZhengYP

clients/client-accessanalyzer/src/protocols/Aws_restJson1.ts

@@ -140,8 +140,7 @@ const deserializeAws_restJson1DeleteAlternateContactCommandError = async (
     body: await parseBody(output.body, context),
   };
   let response: __BaseException;
-  let errorCode = "UnknownError";
-  errorCode = loadRestJsonErrorCode(output, parsedOutput.body);
+  const errorCode = loadRestJsonErrorCode(output, parsedOutput.body);
   switch (errorCode) {
     case "AccessDeniedException":
     case "com.amazonaws.account#AccessDeniedException":
@@ -160,10 +159,12 @@ const deserializeAws_restJson1DeleteAlternateContactCommandError = async (
       throw await deserializeAws_restJson1ValidationExceptionResponse(parsedOutput, context);
     default:
       const parsedBody = parsedOutput.body;
+      const $metadata = deserializeMetadata(output);
+      const statusCode = $metadata.httpStatusCode ? $metadata.httpStatusCode + "" : undefined;
       response = new __BaseException({
-        name: parsedBody.code || parsedBody.Code || errorCode,
+        name: parsedBody.code || parsedBody.Code || errorCode || statusCode || "UnknowError",
         $fault: "client",
-        $metadata: deserializeMetadata(output),
+        $metadata,
       });
       throw __decorateServiceException(response, parsedBody);
   }
@@ -196,8 +197,7 @@ const deserializeAws_restJson1GetAlternateContactCommandError = async (
     body: await parseBody(output.body, context),
   };
   let response: __BaseException;
-  let errorCode = "UnknownError";
-  errorCode = loadRestJsonErrorCode(output, parsedOutput.body);
+  const errorCode = loadRestJsonErrorCode(output, parsedOutput.body);
   switch (errorCode) {
     case "AccessDeniedException":
     case "com.amazonaws.account#AccessDeniedException":
@@ -216,10 +216,12 @@ const deserializeAws_restJson1GetAlternateContactCommandError = async (
       throw await deserializeAws_restJson1ValidationExceptionResponse(parsedOutput, context);
     default:
       const parsedBody = parsedOutput.body;
+      const $metadata = deserializeMetadata(output);
+      const statusCode = $metadata.httpStatusCode ? $metadata.httpStatusCode + "" : undefined;
       response = new __BaseException({
-        name: parsedBody.code || parsedBody.Code || errorCode,
+        name: parsedBody.code || parsedBody.Code || errorCode || statusCode || "UnknowError",
         $fault: "client",
-        $metadata: deserializeMetadata(output),
+        $metadata,
       });
       throw __decorateServiceException(response, parsedBody);
   }
@@ -248,8 +250,7 @@ const deserializeAws_restJson1PutAlternateContactCommandError = async (
     body: await parseBody(output.body, context),
   };
   let response: __BaseException;
-  let errorCode = "UnknownError";
-  errorCode = loadRestJsonErrorCode(output, parsedOutput.body);
+  const errorCode = loadRestJsonErrorCode(output, parsedOutput.body);
   switch (errorCode) {
     case "AccessDeniedException":
     case "com.amazonaws.account#AccessDeniedException":
@@ -265,10 +266,12 @@ const deserializeAws_restJson1PutAlternateContactCommandError = async (
       throw await deserializeAws_restJson1ValidationExceptionResponse(parsedOutput, context);
     default:
       const parsedBody = parsedOutput.body;
+      const $metadata = deserializeMetadata(output);
+      const statusCode = $metadata.httpStatusCode ? $metadata.httpStatusCode + "" : undefined;
       response = new __BaseException({
-        name: parsedBody.code || parsedBody.Code || errorCode,
+        name: parsedBody.code || parsedBody.Code || errorCode || statusCode || "UnknowError",
         $fault: "client",
-        $metadata: deserializeMetadata(output),
+        $metadata,
       });
       throw __decorateServiceException(response, parsedBody);
   }
@@ -401,7 +404,7 @@ const parseBody = (streamBody: any, context: __SerdeContext): any =>
 /**
  * Load an error code for the aws.rest-json-1.1 protocol.
  */
-const loadRestJsonErrorCode = (output: __HttpResponse, data: any): string => {
+const loadRestJsonErrorCode = (output: __HttpResponse, data: any): string | undefined => {
   const findKey = (object: any, key: string) => Object.keys(object).find((k) => k.toLowerCase() === key.toLowerCase());
 
   const sanitizeErrorCode = (rawValue: string): string => {
@@ -427,6 +430,4 @@ const loadRestJsonErrorCode = (output: __HttpResponse, data: any): string => {
   if (data["__type"] !== undefined) {
     return sanitizeErrorCode(data["__type"]);
   }
-
-  return "";
 };