From ce1200bf1f4b99907582cce4c6d31080303c33f8 Mon Sep 17 00:00:00 2001
From: juanvallejo <jvallejo@redhat.com>
Date: Fri, 16 Dec 2016 16:43:27 -0500
Subject: [PATCH] return typed json,yaml syntax errors

This patch creates error types for JSON and YAML syntax errors to make
it easier to handle these types of errors by callers of JSON and YAML
decoders.
---
 .../apimachinery/pkg/util/yaml/decoder.go     | 27 ++++++++++++---
 .../pkg/util/yaml/decoder_test.go             | 33 +++++++++++++++++++
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder.go b/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder.go
index 27b7500eba9..6ebfaea707d 100644
--- a/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder.go
+++ b/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder.go
@@ -69,11 +69,10 @@ func (d *YAMLToJSONDecoder) Decode(into interface{}) error {
 	}
 
 	if len(bytes) != 0 {
-		data, err := yaml.YAMLToJSON(bytes)
+		err := yaml.Unmarshal(bytes, into)
 		if err != nil {
-			return err
+			return YAMLSyntaxError{err}
 		}
-		return json.Unmarshal(data, into)
 	}
 	return err
 }
@@ -184,6 +183,23 @@ type YAMLOrJSONDecoder struct {
 	rawData []byte
 }
 
+type JSONSyntaxError struct {
+	Line int
+	Err  error
+}
+
+func (e JSONSyntaxError) Error() string {
+	return fmt.Sprintf("json: line %d: %s", e.Line, e.Err.Error())
+}
+
+type YAMLSyntaxError struct {
+	err error
+}
+
+func (e YAMLSyntaxError) Error() string {
+	return e.err.Error()
+}
+
 // NewYAMLOrJSONDecoder returns a decoder that will process YAML documents
 // or JSON documents from the given reader as a stream. bufferSize determines
 // how far into the stream the decoder will look to figure out whether this
@@ -226,7 +242,10 @@ func (d *YAMLOrJSONDecoder) Decode(into interface{}) error {
 
 			start := strings.LastIndex(js[:syntax.Offset], "\n") + 1
 			line := strings.Count(js[:start], "\n")
-			return fmt.Errorf("json: line %d: %s", line, syntax.Error())
+			return JSONSyntaxError{
+				Line: line,
+				Err:  fmt.Errorf(syntax.Error()),
+			}
 		}
 	}
 	return err
diff --git a/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder_test.go b/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder_test.go
index 5712b30794a..54daec27432 100644
--- a/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder_test.go
+++ b/staging/src/k8s.io/apimachinery/pkg/util/yaml/decoder_test.go
@@ -314,3 +314,36 @@ func testReadLines(t *testing.T, lineLengths []int) {
 		}
 	}
 }
+
+func TestTypedJSONOrYamlErrors(t *testing.T) {
+	s := NewYAMLOrJSONDecoder(bytes.NewReader([]byte(`{
+	"foo": {
+		"stuff": 1
+		"otherStuff": 2
+	}
+}
+  `)), 100)
+	obj := generic{}
+	err := s.Decode(&obj)
+	if err == nil {
+		t.Fatal("expected error with json: prefix, got no error")
+	}
+	if _, ok := err.(JSONSyntaxError); !ok {
+		t.Fatalf("expected %q to be of type JSONSyntaxError", err.Error())
+	}
+
+	s = NewYAMLOrJSONDecoder(bytes.NewReader([]byte(`---
+stuff: 1
+		test-foo: 1
+
+---
+  `)), 100)
+	obj = generic{}
+	err = s.Decode(&obj)
+	if err == nil {
+		t.Fatal("expected error with yaml: prefix, got no error")
+	}
+	if _, ok := err.(YAMLSyntaxError); !ok {
+		t.Fatalf("expected %q to be of type YAMLSyntaxError", err.Error())
+	}
+}