add serialization unit tests

datanode.go

@@ -652,7 +652,6 @@ func FromBytes(bs []byte) (*dataNode, error) {
 	}
 
 	node := dataNode{
-		values: map[string]any{},
 		// FIXME: do something with the serialized commments.
 		// I'm punting on this for now because I want to figure
 		// out the best middle ground between avoiding a slice of
@@ -663,12 +662,18 @@ func FromBytes(bs []byte) (*dataNode, error) {
 		// need to introduce a delimiter.
 	}
 
+	if len(core.Values) > 0 {
+		node.values = map[string]any{}
+	}
+
 	for k, v := range core.Values {
 		node.values[k] = v
 	}
 
-	node.otel = &otelClient{
-		serviceName: core.OTELServiceName,
+	if len(core.OTELServiceName) > 0 {
+		node.otel = &otelClient{
+			serviceName: core.OTELServiceName,
+		}
 	}
 
 	return &node, nil

datanode_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -12,7 +13,6 @@ import (
 // ---------------------------------------------------------------------------
 
 func TestDataNode_Init(t *testing.T) {
-
 	table := []struct {
 		name string
 		node *dataNode
@@ -42,3 +42,82 @@ func TestDataNode_Init(t *testing.T) {
 		})
 	}
 }
+
+func TestBytes(t *testing.T) {
+	table := []struct {
+		name                 string
+		node                 func() *dataNode
+		expectSerialized     []byte
+		expectDeserialized   *dataNode
+		expectDeserializeErr require.ErrorAssertionFunc
+	}{
+		{
+			name: "nil",
+			node: func() *dataNode {
+				return nil
+			},
+			expectSerialized:     []byte{},
+			expectDeserialized:   nil,
+			expectDeserializeErr: require.Error,
+		},
+		{
+			name: "empty",
+			node: func() *dataNode {
+				return &dataNode{}
+			},
+			expectSerialized:     []byte(`{"otelServiceName":"","values":{},"comments":[]}`),
+			expectDeserialized:   &dataNode{},
+			expectDeserializeErr: require.NoError,
+		},
+		{
+			name: "with values",
+			node: func() *dataNode {
+				return &dataNode{
+					otel: &otelClient{
+						serviceName: "serviceName",
+					},
+					values: map[string]any{
+						"fisher":  "flannigan",
+						"fitzbog": nil,
+					},
+					comment: comment{
+						Caller:  "i am caller",
+						File:    "i am file",
+						Message: "i am message",
+					},
+				}
+			},
+			expectSerialized: []byte(`{"otelServiceName":"serviceName",` +
+				`"values":{"fisher":"flannigan","fitzbog":""},` +
+				`"comments":[{"Caller":"i am caller","File":"i am file","Message":"i am message"}]}`),
+			expectDeserialized: &dataNode{
+				otel: &otelClient{
+					serviceName: "serviceName",
+				},
+				values: map[string]any{
+					"fisher":  "flannigan",
+					"fitzbog": "",
+				},
+			},
+			expectDeserializeErr: require.NoError,
+		},
+	}
+	for _, test := range table {
+		t.Run(test.name, func(t *testing.T) {
+			serialized, err := test.node().Bytes()
+			require.NoError(t, err)
+
+			assert.Equalf(
+				t,
+				test.expectSerialized,
+				serialized,
+				"expected:\t%s\ngot:\t\t%s\n",
+				string(test.expectSerialized),
+				string(serialized))
+
+			deserialized, err := FromBytes(serialized)
+			test.expectDeserializeErr(t, err)
+			require.Equal(t, test.expectDeserialized, deserialized)
+		})
+	}
+}