From 8f2b31b008e95a8a40c1c5ce75b7c5e93e08a300 Mon Sep 17 00:00:00 2001
From: "Lubomir I. Ivanov" <neolit123@gmail.com>
Date: Fri, 2 Nov 2018 17:45:52 +0200
Subject: [PATCH] UnmarshalStrict: use DisallowUnknownFields

Without this option the JSON decoder would tolerate
unknown fields.
---
 yaml.go      | 2 +-
 yaml_test.go | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/yaml.go b/yaml.go
index ec24ab5..457c9de 100644
--- a/yaml.go
+++ b/yaml.go
@@ -39,7 +39,7 @@ func Unmarshal(y []byte, o interface{}, opts ...JSONOpt) error {
 // UnmarshalStrict strictly converts YAML to JSON then uses JSON to unmarshal
 // into an object, optionally configuring the behavior of the JSON unmarshal.
 func UnmarshalStrict(y []byte, o interface{}, opts ...JSONOpt) error {
-	return yamlUnmarshal(y, o, true, opts...)
+	return yamlUnmarshal(y, o, true, append(opts, DisallowUnknownFields)...)
 }
 
 // yamlUnmarshal unmarshals the given YAML byte stream into the given interface,
diff --git a/yaml_test.go b/yaml_test.go
index ad6b2e0..42a2315 100644
--- a/yaml_test.go
+++ b/yaml_test.go
@@ -211,6 +211,15 @@ a:
 `)
 	s4 := NamedThing{}
 	unmarshalStrictFail(t, y, &s4)
+
+	// Strict unmarshal should fail for unknown fields
+	y = []byte(`
+name: TestB
+id: ID-B
+unknown: Some-Value
+`)
+	s5 := NamedThing{}
+	unmarshalStrictFail(t, y, &s5)
 }
 
 func unmarshalStrict(t *testing.T, y []byte, s, e interface{}, opts ...JSONOpt) {