Add unmarshal for ExporterType

trace/exporter_type.go

@@ -10,14 +10,22 @@ import (
 )
 
 const (
-	GRPC ExporterType = iota + 1
+	NoOp ExporterType = iota
+	GRPC
 	HTTP
 )
 
-var errUnknownExporterType = errors.New("unknown exporter type")
+var (
+	errUnknownExporterType = errors.New("unknown exporter type")
+	errInvalidFormat       = errors.New("invalid format")
+)
 
 func ExporterTypeFromString(exporterTypeStr string) (ExporterType, error) {
 	switch strings.ToLower(exporterTypeStr) {
+	case NoOp.String():
+		return 0, nil
+	case "null":
+		return 0, nil
 	case GRPC.String():
 		return GRPC, nil
 	case HTTP.String():
@@ -33,8 +41,23 @@ func (t ExporterType) MarshalJSON() ([]byte, error) {
 	return []byte(`"` + t.String() + `"`), nil
 }
 
+func (t *ExporterType) UnmarshalJSON(b []byte) error {
+	exporterTypeStr, err := stripQuotes(string(b))
+	if err != nil {
+		return err
+	}
+	exporterType, err := ExporterTypeFromString(exporterTypeStr)
+	if err != nil {
+		return err
+	}
+	*t = exporterType
+	return nil
+}
+
 func (t ExporterType) String() string {
 	switch t {
+	case NoOp:
+		return ""
 	case GRPC:
 		return "grpc"
 	case HTTP:
@@ -43,3 +66,10 @@ func (t ExporterType) String() string {
 		return "unknown"
 	}
 }
+
+func stripQuotes(s string) (string, error) {
+	if len(s) < 2 || s[0] != '"' || s[len(s)-1] != '"' {
+		return "", errInvalidFormat
+	}
+	return s[1 : len(s)-1], nil
+}

trace/exporter_type_test.go

@@ -0,0 +1,96 @@
+// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package trace
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMarshalUnmarshal(t *testing.T) {
+	tests := []struct {
+		Name         string
+		ExporterType ExporterType
+		ExpectedErr  error
+	}{
+		{
+			Name:         "GRPC",
+			ExporterType: GRPC,
+		},
+		{
+			Name:         "HTTP",
+			ExporterType: HTTP,
+		},
+		{
+			Name:         "NoOp",
+			ExporterType: NoOp,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			require := require.New(t)
+
+			b, err := json.Marshal(tt.ExporterType)
+			require.NoError(err)
+
+			var et ExporterType
+			require.NoError(json.Unmarshal(b, &et))
+
+			require.Equal(tt.ExporterType, et)
+		})
+	}
+}
+
+func TestUnmarshal(t *testing.T) {
+	tests := []struct {
+		Name          string
+		Str           string
+		ExpectedError error
+	}{
+		{
+			Name:          "NoQuotes",
+			Str:           "grpc",
+			ExpectedError: errInvalidFormat,
+		},
+		{
+			Name:          "SingleLeftQuote",
+			Str:           "\"grpc",
+			ExpectedError: errInvalidFormat,
+		},
+		{
+			Name:          "SingleRightQuote",
+			Str:           "grpc\"",
+			ExpectedError: errInvalidFormat,
+		},
+		{
+			Name:          "MultipleQuotes",
+			Str:           "\"\"grpc\"\"\"",
+			ExpectedError: errUnknownExporterType,
+		},
+		{
+			Name:          "NullString",
+			Str:           "\"null\"",
+			ExpectedError: nil,
+		},
+		{
+			Name:          "EmptyString",
+			Str:           "\"\"",
+			ExpectedError: nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			require := require.New(t)
+
+			var et ExporterType
+
+			err := et.UnmarshalJSON([]byte(tt.Str))
+			require.ErrorIs(err, tt.ExpectedError)
+		})
+	}
+}