Migrate discard / collect unknown to smithyjson

aws/protocol/restjson/decoder_util.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/awslabs/smithy-go"
+	smithyjson "github.com/awslabs/smithy-go/json"
 )
 
 // GetErrorInfo util looks for code, __type, and message members in the
@@ -41,7 +42,7 @@ func GetErrorInfo(decoder *json.Decoder) (errorType string, message string, err
 		case strings.EqualFold(st, "message"):
 			target = &message
 		default:
-			DiscardUnknownField(decoder)
+			smithyjson.DiscardUnknownField(decoder)
 			continue
 		}
 
@@ -83,34 +84,7 @@ func SanitizeErrorCode(errorCode string) string {
 	return errorCode
 }
 
-// DiscardUnknownField discards unknown fields from decoder body.
-// This function is useful while deserializing json body with additional
-// unknown information that should be discarded.
-func DiscardUnknownField(decoder *json.Decoder) error {
-	v, err := decoder.Token()
-	if err == io.EOF {
-		return nil
-	}
-	if err != nil {
-		return err
-	}
 
-	if _, ok := v.(json.Delim); ok {
-		for decoder.More() {
-			err = DiscardUnknownField(decoder)
-		}
-		endToken, err := decoder.Token()
-		if err != nil {
-			return err
-		}
-		if _, ok := endToken.(json.Delim); !ok {
-			return fmt.Errorf("invalid JSON : expected json delimiter, found %T %v",
-				endToken, endToken)
-		}
-	}
-
-	return nil
-}
 
 // GetSmithyGenericAPIError returns smithy generic api error and an error interface.
 // Takes in json decoder, and error Code string as args. The function retrieves error message

codegen/smithy-aws-go-codegen/src/main/java/software/amazon/smithy/aws/go/codegen/JsonShapeDeserVisitor.java

@@ -206,8 +206,8 @@ protected void deserializeStructure(GenerationContext context, StructureShape sh
                 }
 
                 writer.openBlock("default:", "", () -> {
-                    writer.addUseImports(AwsGoDependency.AWS_REST_JSON_PROTOCOL);
-                    writer.write("err := restjson.DiscardUnknownField(decoder)");
+                    writer.addUseImports(SmithyGoDependency.SMITHY_JSON);
+                    writer.write("err := smithyjson.DiscardUnknownField(decoder)");
                     writer.write("if err != nil {return err}");
                 });
             });
@@ -262,10 +262,10 @@ protected void deserializeUnion(GenerationContext context, UnionShape shape) {
                         UnionGenerator.UNKNOWN_MEMBER_NAME,
                         symbol.getNamespace()
                 ).build();
-                writer.addUseImports(AwsGoDependency.AWS_REST_JSON_PROTOCOL);
+                writer.addUseImports(SmithyGoDependency.SMITHY_JSON);
                 writer.write("tagString, ok := t.(string)");
                 writer.write("if !ok { return fmt.Errorf(\"expected string key, found %T\", t) }");
-                writer.write("value, err := restjson.CollectUnknownField(decoder)");
+                writer.write("value, err := smithyjson.CollectUnknownField(decoder)");
                 writer.write("if err != nil { return err }");
                 writer.write("uv = &$T{Tag: tagString, Value: value}", unknownMemberSymbol);
             });