improve error handling

cmd/s3select/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"os"
 
@@ -15,10 +16,7 @@ const (
 
 	// Errors start at 10
 	ExitCodeError = 10 + iota
-	ExitCodeParseFlagsError
-	ExitCodeLoggerError
-	ExitCodeCloudError
-	ExitCodeObjectListingError
+	ExitCodeInitializeError
 )
 
 func main() {
@@ -36,14 +34,20 @@ func run(args []string) int {
 	logger, err := log.New(logLevel)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "failed to generate logger: %s", err.Error())
+		return ExitCodeInitializeError
 	}
 	cliFactory, err := cli.NewFactory(buildVersion, logger)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "failed to initialize process: %s", err.Error())
+		return ExitCodeInitializeError
 	}
 	rootCmd := root.NewCmdRoot(cliFactory, buildVersion, buildDate)
 
 	if _, err := rootCmd.ExecuteC(); err != nil {
+		switch {
+		case errors.Is(err, cli.ValidateConfigError):
+			// advice for configuration
+		}
 		fmt.Fprintln(os.Stderr, err.Error())
 	}
 

pkg/cli/errors.go

@@ -0,0 +1,7 @@
+package cli
+
+import "errors"
+
+var (
+	ValidateConfigError = errors.New("ValidateConfigError")
+)

pkg/query/object_selector.go

@@ -5,14 +5,15 @@ import (
 	"io"
 
 	"github.com/44smkn/s3select/pkg/aws"
+	"github.com/44smkn/s3select/pkg/cli"
 	"github.com/44smkn/s3select/pkg/config"
 	awssdk "github.com/aws/aws-sdk-go/aws"
 	awsclient "github.com/aws/aws-sdk-go/aws/client"
 	awsrequest "github.com/aws/aws-sdk-go/aws/request"
 	"github.com/aws/aws-sdk-go/service/s3"
 	s3sdk "github.com/aws/aws-sdk-go/service/s3"
+	"github.com/pkg/errors"
 	"go.uber.org/zap"
-	"golang.org/x/xerrors"
 )
 
 type ObjectSelector interface {
@@ -64,7 +65,7 @@ func (s defaultObjectSelector) Select(ctx context.Context, meta *ObjectMetadata,
 		r.Handlers.Send.RemoveByName(awsclient.LogHTTPResponseHeaderHandler.Name)
 	})
 	if err != nil {
-		return xerrors.Errorf("failed to execute s3api: %w", err)
+		return errors.Errorf("failed to execute s3api: %w", err)
 	}
 	defer resp.EventStream.Close()
 
@@ -100,7 +101,7 @@ func newInputSerialization(cfg *config.InputSerialization) (*s3sdk.InputSerializ
 			},
 		}, nil
 	default:
-		return nil, xerrors.New("choose a input format type from: [json, csv]")
+		return nil, errors.Errorf("choose a input format type from: [json, csv]: %w", cli.ValidateConfigError)
 	}
 }
 
@@ -123,6 +124,6 @@ func newOutputSerialization(cfg *config.OutputSerialization) (*s3sdk.OutputSeria
 			},
 		}, nil
 	default:
-		return nil, xerrors.New("choose a output format type from: [json, csv]")
+		return nil, errors.Errorf("choose a output format type from: [json, csv]: %w", cli.ValidateConfigError)
 	}
 }