feat: sc-240965/check current access token (#324)

Check if access token is set before logging in

cmd/config/config.go

@@ -228,13 +228,7 @@ func getConfig() (config.ConfigFile, *viper.Viper, error) {
 		return config.ConfigFile{}, nil, err
 	}
 
-	data, err := os.ReadFile(v.ConfigFileUsed())
-	if err != nil {
-		return config.ConfigFile{}, nil, err
-	}
-
-	var c config.ConfigFile
-	err = yaml.Unmarshal([]byte(data), &c)
+	c, err := config.NewConfigFromFile(v.ConfigFileUsed(), os.ReadFile)
 	if err != nil {
 		return config.ConfigFile{}, nil, err
 	}

cmd/login/login.go

@@ -10,6 +10,7 @@ import (
 	cmdAnalytics "github.com/launchdarkly/ldcli/cmd/analytics"
 	"github.com/launchdarkly/ldcli/cmd/cliflags"
 	"github.com/launchdarkly/ldcli/internal/analytics"
+	"github.com/launchdarkly/ldcli/internal/config"
 	"github.com/launchdarkly/ldcli/internal/login"
 	"github.com/launchdarkly/ldcli/internal/output"
 )
@@ -54,6 +55,10 @@ func NewLoginCmd(
 
 func run(client login.Client) func(*cobra.Command, []string) error {
 	return func(cmd *cobra.Command, args []string) error {
+		if ok, err := config.AccessTokenIsSet(viper.GetViper().ConfigFileUsed()); !ok {
+			return err
+		}
+
 		deviceAuthorization, err := login.FetchDeviceAuthorization(
 			client,
 			login.ClientID,

internal/config/config.go

@@ -7,6 +7,7 @@ import (
 	"strconv"
 
 	"github.com/mitchellh/go-homedir"
+	"gopkg.in/yaml.v3"
 
 	"github.com/launchdarkly/ldcli/cmd/cliflags"
 	"github.com/launchdarkly/ldcli/internal/errors"
@@ -26,6 +27,23 @@ type ConfigFile struct {
 	Project         string `json:"project,omitempty" yaml:"project,omitempty"`
 }
 
+type ReadFile func(name string) ([]byte, error)
+
+func NewConfigFromFile(f string, readFile ReadFile) (ConfigFile, error) {
+	data, err := readFile(f)
+	if err != nil {
+		return ConfigFile{}, errors.NewError("could not read config file")
+	}
+
+	var c ConfigFile
+	err = yaml.Unmarshal([]byte(data), &c)
+	if err != nil {
+		return ConfigFile{}, errors.NewError("config file is invalid yaml")
+	}
+
+	return c, nil
+}
+
 func NewConfig(rawConfig map[string]interface{}) (ConfigFile, error) {
 	var (
 		accessToken     string
@@ -91,3 +109,15 @@ func GetConfigFile() string {
 
 	return filepath.Join(configFilePath, "config.yml")
 }
+
+func AccessTokenIsSet(filename string) (bool, error) {
+	config, err := NewConfigFromFile(filename, os.ReadFile)
+	if err != nil {
+		return false, err
+	}
+	if config.AccessToken != "" {
+		return false, errors.NewError("Your access token is already set. Remove it from the config if you wish to reset it.")
+	}
+
+	return true, nil
+}

internal/config/config_test.go

@@ -8,11 +8,65 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
 
 	"github.com/launchdarkly/ldcli/internal/config"
 	"github.com/launchdarkly/ldcli/internal/resources"
 )
 
+type mockReadFile struct {
+	contents   []byte
+	successful bool
+}
+
+func (m mockReadFile) readFile(name string) ([]byte, error) {
+	if !m.successful {
+		return nil, errors.New("an error")
+	}
+
+	if m.contents != nil {
+		return yaml.Marshal(m.contents)
+	}
+
+	return yaml.Marshal(map[string]interface{}{
+		"access-token": "test-access-token",
+	})
+}
+
+func TestNewConfigFromFile(t *testing.T) {
+	t.Run("with valid input is a valid config", func(t *testing.T) {
+		mock := mockReadFile{
+			successful: true,
+		}
+
+		c, err := config.NewConfigFromFile("test-config-file", mock.readFile)
+
+		require.NoError(t, err)
+		assert.Equal(t, "test-access-token", c.AccessToken)
+	})
+
+	t.Run("with invalid file is an error", func(t *testing.T) {
+		mock := mockReadFile{
+			successful: false,
+		}
+
+		_, err := config.NewConfigFromFile("test-config-file", mock.readFile)
+
+		assert.EqualError(t, err, "could not read config file")
+	})
+
+	t.Run("with invalid formatting in the file contents is an error", func(t *testing.T) {
+		mock := mockReadFile{
+			contents:   []byte(`invalid`),
+			successful: true,
+		}
+
+		_, err := config.NewConfigFromFile("test-config-file", mock.readFile)
+
+		assert.EqualError(t, err, "config file is invalid yaml")
+	})
+}
+
 func TestNewConfig(t *testing.T) {
 	t.Run("analytics-opt-out", func(t *testing.T) {
 		tests := map[string]struct {