Expose flag names as public consts

Author: bufdev

client.go

@@ -173,7 +173,7 @@ func (c *client) Call(
 	if len(args) == 0 {
 		args = []string{procedure.Path()}
 	}
-	args = append(args, "--"+flagFormat, c.format.String())
+	args = append(args, "--"+FormatFlagName, c.format.String())
 	if err := c.runner.Run(
 		ctx,
 		Env{
@@ -198,7 +198,7 @@ func (c *client) getSpecUncached(ctx context.Context) (Spec, error) {
 	if err := c.runner.Run(
 		ctx,
 		Env{
-			Args:   []string{"--" + flagSpec, "--" + flagFormat, c.format.String()},
+			Args:   []string{"--" + SpecFlagName, "--" + FormatFlagName, c.format.String()},
 			Stdout: stdout,
 			Stderr: c.stderr,
 		},
@@ -207,11 +207,11 @@ func (c *client) getSpecUncached(ctx context.Context) (Spec, error) {
 	}
 	data := stdout.Bytes()
 	if len(data) == 0 {
-		return nil, fmt.Errorf("--%s did not return a spec", flagSpec)
+		return nil, fmt.Errorf("--%s did not return a spec", SpecFlagName)
 	}
 	protoSpec := &pluginrpcv1.Spec{}
 	if err := unmarshalSpec(c.format, data, protoSpec); err != nil {
-		return nil, fmt.Errorf("--%s did not return a properly-formed spec: %w", flagSpec, err)
+		return nil, fmt.Errorf("--%s did not return a properly-formed spec: %w", SpecFlagName, err)
 	}
 	return NewSpecForProto(protoSpec)
 }
@@ -222,7 +222,7 @@ func (c *client) checkProtocolVersion(ctx context.Context) error {
 		return err
 	}
 	if version != protocolVersion {
-		return fmt.Errorf("--%s returned unknown protocol version %d", flagProtocol, version)
+		return fmt.Errorf("--%s returned unknown protocol version %d", ProtocolFlagName, version)
 	}
 	return nil
 }
@@ -232,7 +232,7 @@ func (c *client) getProtocolVersionUncached(ctx context.Context) (int, error) {
 	if err := c.runner.Run(
 		ctx,
 		Env{
-			Args:   []string{"--" + flagProtocol},
+			Args:   []string{"--" + ProtocolFlagName},
 			Stdout: stdout,
 			Stderr: c.stderr,
 		},
@@ -241,11 +241,11 @@ func (c *client) getProtocolVersionUncached(ctx context.Context) (int, error) {
 	}
 	data := stdout.Bytes()
 	if len(data) == 0 {
-		return 0, fmt.Errorf("--%s did not return a protocol version", flagProtocol)
+		return 0, fmt.Errorf("--%s did not return a protocol version", ProtocolFlagName)
 	}
 	version, err := unmarshalProtocol(data)
 	if err != nil {
-		return 0, fmt.Errorf("--%s did not return a properly-formed protocol version: %w", flagProtocol, err)
+		return 0, fmt.Errorf("--%s did not return a properly-formed protocol version: %w", ProtocolFlagName, err)
 	}
 	return version, nil
 }

flags.go

@@ -24,10 +24,14 @@ import (
 )
 
 const (
+	// ProtocolFlagName is the name of the protocol bool flag.
+	ProtocolFlagName = "protocol"
+	// SpecFlagName is the name of the spec bool flag.
+	SpecFlagName = "spec"
+	// FormatFlagName is the name of the format string flag.
+	FormatFlagName = "format"
+
 	protocolVersion = 1
-	flagProtocol    = "protocol"
-	flagSpec        = "spec"
-	flagFormat      = "format"
 )
 
 type flags struct {
@@ -41,20 +45,20 @@ func parseFlags(output io.Writer, args []string) (*flags, []string, error) {
 	var formatString string
 	flagSet := pflag.NewFlagSet("plugin", pflag.ContinueOnError)
 	flagSet.SetOutput(output)
-	flagSet.BoolVar(&flags.printProtocol, flagProtocol, false, "Print the protocol to stdout and exit.")
-	flagSet.BoolVar(&flags.printSpec, flagSpec, false, "Print the spec to stdout in the specified format and exit.")
-	flagSet.StringVar(&formatString, flagFormat, formatBinaryString, fmt.Sprintf("The format to use for requests, responses, and specs. Must be one of [%q, %q].", formatBinaryString, formatJSONString))
+	flagSet.BoolVar(&flags.printProtocol, ProtocolFlagName, false, "Print the protocol to stdout and exit.")
+	flagSet.BoolVar(&flags.printSpec, SpecFlagName, false, "Print the spec to stdout in the specified format and exit.")
+	flagSet.StringVar(&formatString, FormatFlagName, formatBinaryString, fmt.Sprintf("The format to use for requests, responses, and specs. Must be one of [%q, %q].", formatBinaryString, formatJSONString))
 	if err := flagSet.Parse(args); err != nil {
 		return nil, nil, err
 	}
 	if flags.printProtocol && flags.printSpec {
-		return nil, nil, fmt.Errorf("cannot specify both --%s and --%s", flagProtocol, flagSpec)
+		return nil, nil, fmt.Errorf("cannot specify both --%s and --%s", ProtocolFlagName, SpecFlagName)
 	}
 	format := FormatBinary
 	if formatString != "" {
 		format = FormatForString(formatString)
 		if format == 0 {
-			return nil, nil, fmt.Errorf("invalid value for --%s: %q", flagFormat, formatString)
+			return nil, nil, fmt.Errorf("invalid value for --%s: %q", FormatFlagName, formatString)
 		}
 	}
 	if err := validateFormat(format); err != nil {