Merge pull request #115 from PaulSonOfLars/diffErrorCodes

Change exit code behaviour to return debuggable values

internal/cmd/cmd.go

@@ -43,7 +43,7 @@ func Do(
 	switch {
 	case len(args) == 0:
 		_, _ = fmt.Fprint(stderr, help)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	default:
 		return doSub(
 			args,
@@ -78,18 +78,18 @@ func doLint(
 	if len(args) < 1 {
 		_, _ = fmt.Fprintln(stderr, "protolint lint requires at least one argument. See Usage.")
 		_, _ = fmt.Fprint(stderr, help)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 
 	flags, err := lint.NewFlags(args)
 	if err != nil {
 		_, _ = fmt.Fprint(stderr, err)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 	if len(flags.Args()) < 1 {
 		_, _ = fmt.Fprintln(stderr, "protolint lint requires at least one argument. See Usage.")
 		_, _ = fmt.Fprint(stderr, help)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 
 	subCmd, err := lint.NewCmdLint(
@@ -99,7 +99,7 @@ func doLint(
 	)
 	if err != nil {
 		_, _ = fmt.Fprint(stderr, err)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 	return subCmd.Run()
 }

internal/cmd/protocgenprotolint/cmd.go

@@ -39,7 +39,7 @@ func Do(
 	subCmd, err := newSubCmd(stdin, stdout, stderr)
 	if err != nil {
 		_, _ = fmt.Fprintln(stderr, err)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 	return subCmd.Run()
 }

internal/cmd/subcmds/lint/cmdLint.go

@@ -66,17 +66,17 @@ func (c *CmdLint) Run() osutil.ExitCode {
 	failures, err := c.run()
 	if err != nil {
 		_, _ = fmt.Fprintln(c.stderr, err)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 
 	err = c.config.reporter.Report(c.output, failures)
 	if err != nil {
 		_, _ = fmt.Fprintln(c.stderr, err)
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 
 	if 0 < len(failures) {
-		return osutil.ExitFailure
+		return osutil.ExitLintFailure
 	}
 
 	return osutil.ExitSuccess
@@ -95,6 +95,15 @@ func (c *CmdLint) run() ([]report.Failure, error) {
 	return allFailures, nil
 }
 
+// ParseError represents the error returned through a parsing exception.
+type ParseError struct {
+	Message string
+}
+
+func (p ParseError) Error() string {
+	return p.Message
+}
+
 func (c *CmdLint) runOneFile(
 	f file.ProtoFile,
 ) ([]report.Failure, error) {
@@ -111,9 +120,9 @@ func (c *CmdLint) runOneFile(
 	proto, err := f.Parse(c.config.verbose)
 	if err != nil {
 		if c.config.verbose {
-			return nil, err
+			return nil, ParseError{Message: err.Error()}
 		}
-		return nil, fmt.Errorf("%s. Use -v for more details", err)
+		return nil, ParseError{Message: fmt.Sprintf("%s. Use -v for more details", err)}
 	}
 
 	return c.l.Run(proto, rs)

internal/cmd/subcmds/list/cmdList.go

@@ -33,7 +33,7 @@ func NewCmdList(
 func (c *CmdList) Run() osutil.ExitCode {
 	err := c.run()
 	if err != nil {
-		return osutil.ExitFailure
+		return osutil.ExitInternalFailure
 	}
 	return osutil.ExitSuccess
 }

internal/osutil/exitCode.go

@@ -5,6 +5,7 @@ type ExitCode int
 
 // ExitCode constants.
 const (
-	ExitSuccess ExitCode = iota
-	ExitFailure
+	ExitSuccess         ExitCode = iota
+	ExitLintFailure              // Lint errors, exclusively.
+	ExitInternalFailure          // All other errors: parsing, internal, runtime errors.
 )