From 074eecbb7ef5eb7761befda8781a8d189fdd5c9f Mon Sep 17 00:00:00 2001
From: Richard Knop <richard.knop@esgbook.com>
Date: Thu, 2 May 2024 14:42:52 +0100
Subject: [PATCH] fix: json marshaling of 'contains' schema

---
 keywords_array.go             | 17 +++++++++++++++++
 schema_test.go                |  1 +
 testdata/coding/contains.json |  6 ++++++
 3 files changed, 24 insertions(+)
 create mode 100644 testdata/coding/contains.json

diff --git a/keywords_array.go b/keywords_array.go
index 60badaa..c93067a 100644
--- a/keywords_array.go
+++ b/keywords_array.go
@@ -273,6 +273,23 @@ func (c Contains) JSONChildren() (res map[string]JSONPather) {
 	return Schema(c).JSONChildren()
 }
 
+// MarshalJSON implements the json.Marshaler interface for Schema
+func (c *Contains) MarshalJSON() ([]byte, error) {
+	switch c.schemaType {
+	case schemaTypeFalse:
+		return []byte("false"), nil
+	case schemaTypeTrue:
+		return []byte("true"), nil
+	default:
+		obj := map[string]interface{}{}
+
+		for k, v := range c.keywords {
+			obj[k] = v
+		}
+		return json.Marshal(obj)
+	}
+}
+
 // UnmarshalJSON implements the json.Unmarshaler interface for Contains
 func (c *Contains) UnmarshalJSON(data []byte) error {
 	var sch Schema
diff --git a/schema_test.go b/schema_test.go
index e2fb452..95e0f13 100644
--- a/schema_test.go
+++ b/schema_test.go
@@ -617,6 +617,7 @@ func TestJSONCoding(t *testing.T) {
 		"testdata/coding/numeric.json",
 		"testdata/coding/objects.json",
 		"testdata/coding/strings.json",
+		"testdata/coding/contains.json",
 	}
 
 	for i, c := range cases {
diff --git a/testdata/coding/contains.json b/testdata/coding/contains.json
new file mode 100644
index 0000000..0561b81
--- /dev/null
+++ b/testdata/coding/contains.json
@@ -0,0 +1,6 @@
+{
+  "contains": {
+    "const": "foobar"
+  },
+  "type": "array"
+}
\ No newline at end of file