add custom JSON marshaling for DefaultMetadata

Author: akuzni2

.changeset/famous-doors-ask.md

@@ -0,0 +1,5 @@
+---
+"chainlink-deployments-framework": patch
+---
+
+marshall json without double-encoding

datastore/default_metadata.go

@@ -1,9 +1,31 @@
 package datastore
 
+import "encoding/json"
+
 // DefaultMetadata is a struct that can be used as a default metadata type.
 type DefaultMetadata struct {
 	Data string `json:"data"`
 }
 
 // DefaultMetadata implements the Cloneable interface
-func (d DefaultMetadata) Clone() DefaultMetadata { return d }
+func (dm DefaultMetadata) Clone() DefaultMetadata { return dm }
+
+// MarshalJSON handles both JSON and non-JSON data in the Data field.
+// Without custom marshaling, the Data field would be double-encoded if it contains JSON.
+func (dm DefaultMetadata) MarshalJSON() ([]byte, error) {
+	// Try to parse the Data field as JSON first
+	var jsonData interface{}
+	err := json.Unmarshal([]byte(dm.Data), &jsonData)
+
+	if err == nil {
+		// It's valid JSON, create a custom map
+		return json.Marshal(map[string]interface{}{
+			"data": jsonData,
+		})
+	}
+
+	// Not valid JSON, use normal marshaling. Alias is used to avoid recursion
+	type Alias DefaultMetadata
+
+	return json.Marshal(Alias(dm))
+}

datastore/default_metadata_test.go

@@ -0,0 +1,52 @@
+package datastore
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestDefaultMetadataMarshalJSON(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    DefaultMetadata
+		expected string
+	}{
+		{
+			name:     "Supports any string",
+			input:    DefaultMetadata{Data: "basic data"},
+			expected: `{"data":"basic data"}`,
+		},
+		{
+			name:     "Supports JSON object without double encoding",
+			input:    DefaultMetadata{Data: `{"link":1,"name":"satoshi"}`},
+			expected: `{"data":{"link":1,"name":"satoshi"}}`,
+		},
+		{
+			name:     "Valid JSON array",
+			input:    DefaultMetadata{Data: `[1,2,3,4]`},
+			expected: `{"data":[1,2,3,4]}`,
+		},
+		{
+			name:     "Empty string",
+			input:    DefaultMetadata{Data: ""},
+			expected: `{"data":""}`,
+		},
+		{
+			name:     "Invalid JSON",
+			input:    DefaultMetadata{Data: `{admin:"0xdeadbeef"}`},
+			expected: `{"data":"{admin:\"0xdeadbeef\"}"}`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := json.Marshal(tt.input)
+			require.NoError(t, err)
+			require.NotNil(t, result)
+
+			require.Equal(t, tt.expected, string(result), "Expected output does not match")
+		})
+	}
+}