Add handling for code based exceptions

Author: joewyz

aws/client/aws-client-awsjson/src/it/java/software/amazon/smithy/java/client/aws/jsonprotocols/AwsJson11ProtocolTests.java

@@ -35,12 +35,6 @@ public void requestTest(DataStream expected, DataStream actual) {
     }
 
     @HttpClientResponseTests
-    @ProtocolTestFilter(
-            skipTests = {
-                    "AwsJson11FooErrorUsingCode",
-                    "AwsJson11FooErrorUsingCodeAndNamespace",
-                    "AwsJson11FooErrorUsingCodeUriAndNamespace",
-            })
     public void responseTest(Runnable test) {
         test.run();
     }

aws/client/aws-client-awsjson/src/it/java/software/amazon/smithy/java/client/aws/jsonprotocols/AwsJson1ProtocolTests.java

@@ -51,10 +51,6 @@ public void requestTest(DataStream expected, DataStream actual) {
             skipTests = {
                     "AwsJson10ClientPopulatesDefaultsValuesWhenMissingInResponse",
                     "AwsJson10ClientIgnoresDefaultValuesIfMemberValuesArePresentInResponse",
-                    //The below fail because we haven't implemented code based exception handling
-                    "AwsJson10FooErrorUsingCode",
-                    "AwsJson10FooErrorUsingCodeAndNamespace",
-                    "AwsJson10FooErrorUsingCodeUriAndNamespace",
             },
             skipOperations = "aws.protocoltests.json10#OperationWithRequiredMembersWithDefaults")
     public void responseTest(Runnable test) {

aws/client/aws-client-restjson/src/it/java/software/amazon/smithy/java/client/aws/restjson/RestJson1ProtocolTests.java

@@ -56,12 +56,6 @@ public void requestTest(DataStream expected, DataStream actual) {
     }
 
     @HttpClientResponseTests
-    @ProtocolTestFilter(
-            skipTests = {
-                    "RestJsonFooErrorUsingCode",
-                    "RestJsonFooErrorUsingCodeAndNamespace",
-                    "RestJsonFooErrorUsingCodeUriAndNamespace",
-            })
     public void responseTest(Runnable test) {
         test.run();
     }

codecs/json-codec/src/main/java/software/amazon/smithy/java/json/JsonDocuments.java

@@ -246,9 +246,14 @@ public ShapeType type() {
         @Override
         public ShapeId discriminator() {
             String discriminator = null;
-            var member = values.get("__type");
-            if (member != null && member.type() == ShapeType.STRING) {
-                discriminator = member.asString();
+            var typeMember = values.get("__type");
+            if (typeMember != null && typeMember.type() == ShapeType.STRING) {
+                discriminator = typeMember.asString();
+            } else {
+                var codeMember = values.get("code");
+                if (codeMember != null && codeMember.type() == ShapeType.STRING) {
+                    discriminator = codeMember.asString();
+                }
             }
             if (settings.errorTypeSanitizer() != null) {
                 discriminator = settings.errorTypeSanitizer().apply(discriminator);