New graph.Node method to create a copy

Node.Copy() creates a copy of the node.
It could be useful to return in a query output the modified content of
a node without actually modiying it.

Author: adrianlzt

graffiti/go.mod

@@ -40,6 +40,7 @@ require (
 	github.com/skydive-project/go-debouncer v1.0.0
 	github.com/spf13/cast v1.3.1
 	github.com/spf13/cobra v1.1.1
+	github.com/stretchr/testify v1.5.1
 	github.com/tchap/zapext v1.0.0
 	github.com/xeipuuv/gojsonschema v1.2.0
 	go.uber.org/zap v1.16.0

graffiti/graph/graph.go

@@ -575,6 +575,21 @@ func (n *Node) String() string {
 	return string(b)
 }
 
+func (n *Node) Copy() *Node {
+	return &Node{
+		graphElement: graphElement{
+			ID:        n.ID,
+			Host:      n.Host,
+			Origin:    n.Origin,
+			CreatedAt: n.CreatedAt,
+			UpdatedAt: n.UpdatedAt,
+			DeletedAt: n.DeletedAt,
+			Revision:  n.Revision,
+			Metadata:  n.Metadata.Copy(),
+		},
+	}
+}
+
 // UnmarshalJSON custom unmarshal function
 func (n *Node) UnmarshalJSON(b []byte) error {
 	// wrapper to avoid unmarshal infinite loop

graffiti/graph/graph_test.go

@@ -22,6 +22,9 @@ import (
 	"strconv"
 	"strings"
 	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func newGraph(t *testing.T) *Graph {
@@ -509,6 +512,47 @@ func TestEvents(t *testing.T) {
 	}
 }
 
+func TestNodeCopy(t *testing.T) {
+	n := &Node{
+		graphElement: graphElement{
+			ID:        Identifier("id"),
+			Host:      "Host",
+			Origin:    "Origin",
+			CreatedAt: Time(time.Unix(100, 0)),
+			UpdatedAt: Time(time.Unix(200, 0)),
+			DeletedAt: Time(time.Unix(300, 0)),
+			Revision:  1,
+			Metadata:  Metadata{"foo": "bar"},
+		},
+	}
+
+	cn := n.Copy()
+	assert.Equal(t, n, cn)
+
+	// Check that modifications in the copied node do not affect the origin node
+	ok := cn.Metadata.SetField("new", "value")
+	assert.Truef(t, ok, "copied node set metadata")
+	assert.NotEqualf(t, n, cn, "Metadata")
+
+	cn.Host = "modified"
+	assert.NotEqualf(t, n, cn, "Host")
+
+	cn.Origin = "modified"
+	assert.NotEqualf(t, n, cn, "Origin")
+
+	cn.Revision = 99
+	assert.NotEqualf(t, n, cn, "Revision")
+
+	cn.CreatedAt = Time(time.Unix(100, 99))
+	assert.NotEqualf(t, n, cn, "CreatedAt")
+
+	cn.UpdatedAt = Time(time.Unix(200, 99))
+	assert.NotEqualf(t, n, cn, "UpdatedAt")
+
+	cn.DeletedAt = Time(time.Unix(300, 99))
+	assert.NotEqualf(t, n, cn, "DeletedAt")
+}
+
 type FakeRecursiveListener1 struct {
 	DefaultGraphListener
 	graph *Graph