Merge pull request #18 from cloudingcity/refactor/customize-error-han…

…dling

Refactor/customize error handling

cmd/ci_lint.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"errors"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -11,7 +12,7 @@ var ciLintCmd = &cobra.Command{
 	Short: "Validate the .gitlab-ci.yml",
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("requires a file")}
+			return &errs.ArgError{Err: errors.New("requires a file")}
 		}
 		return nil
 	},

cmd/clone.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"errors"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -11,7 +12,7 @@ var cloneCmd = &cobra.Command{
 	Short: "Clone a repository from GitLab",
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("requires a repository")}
+			return &errs.ArgError{Err: errors.New("requires a repository")}
 		}
 		return nil
 	},

cmd/depend_go.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"errors"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -11,7 +12,7 @@ var dependGOCmd = &cobra.Command{
 	Short: "List go module package (example.com/hello) dependency",
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("requires a package")}
+			return &errs.ArgError{Err: errors.New("requires a package")}
 		}
 		return nil
 	},

cmd/depend_php.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"errors"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -11,7 +12,7 @@ var dependPHPCmd = &cobra.Command{
 	Short: "List composer package (vendor/name) dependency",
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("requires a package")}
+			return &errs.ArgError{Err: errors.New("requires a package")}
 		}
 		return nil
 	},

cmd/mr_open.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strconv"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -14,10 +15,10 @@ var mrOpenCmd = &cobra.Command{
 	DisableFlagsInUseLine: true,
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("missing MRID")}
+			return &errs.ArgError{Err: errors.New("missing MRID")}
 		}
 		if _, err := strconv.Atoi(args[0]); err != nil {
-			return &flagError{fmt.Errorf("invalid MRID %q", args[0])}
+			return &errs.ArgError{Err: fmt.Errorf("invalid MRID %q", args[0])}
 		}
 		return nil
 	},

cmd/mr_search.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"errors"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -11,7 +12,7 @@ var mrSearchCmd = &cobra.Command{
 	Short: "Search merge requests",
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("requires a query")}
+			return &errs.ArgError{Err: errors.New("requires a query")}
 		}
 		return nil
 	},

cmd/mr_show.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strconv"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -14,10 +15,10 @@ var mrShowCmd = &cobra.Command{
 	DisableFlagsInUseLine: true,
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("missing MRID")}
+			return &errs.ArgError{Err: errors.New("missing MRID")}
 		}
 		if _, err := strconv.Atoi(args[0]); err != nil {
-			return &flagError{fmt.Errorf("invalid MRID %q", args[0])}
+			return &errs.ArgError{Err: fmt.Errorf("invalid MRID %q", args[0])}
 		}
 		return nil
 	},

cmd/own_mr_open.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strconv"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -14,16 +15,16 @@ var ownMrOpenCmd = &cobra.Command{
 	DisableFlagsInUseLine: true,
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("missing MRID")}
+			return &errs.ArgError{Err: errors.New("missing MRID")}
 		}
 		if _, err := strconv.Atoi(args[0]); err != nil {
-			return &flagError{fmt.Errorf("invalid MRID %q", args[0])}
+			return &errs.ArgError{Err: fmt.Errorf("invalid MRID %q", args[0])}
 		}
 		if len(args) < 2 {
-			return &flagError{errors.New("missing PID")}
+			return &errs.ArgError{Err: errors.New("missing PID")}
 		}
 		if _, err := strconv.Atoi(args[1]); err != nil {
-			return &flagError{fmt.Errorf("invalid PID %q", args[0])}
+			return &errs.ArgError{Err: fmt.Errorf("invalid PID %q", args[0])}
 		}
 		return nil
 	},

cmd/own_mr_show.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strconv"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -14,16 +15,16 @@ var ownMrShowCmd = &cobra.Command{
 	DisableFlagsInUseLine: true,
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("missing MRID")}
+			return &errs.ArgError{Err: errors.New("missing MRID")}
 		}
 		if _, err := strconv.Atoi(args[0]); err != nil {
-			return &flagError{fmt.Errorf("invalid MRID %q", args[0])}
+			return &errs.ArgError{Err: fmt.Errorf("invalid MRID %q", args[0])}
 		}
 		if len(args) < 2 {
-			return &flagError{errors.New("missing PID")}
+			return &errs.ArgError{Err: errors.New("missing PID")}
 		}
 		if _, err := strconv.Atoi(args[1]); err != nil {
-			return &flagError{fmt.Errorf("invalid PID %q", args[0])}
+			return &errs.ArgError{Err: fmt.Errorf("invalid PID %q", args[0])}
 		}
 		return nil
 	},

cmd/project_search.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"errors"
 
+	errs "github.com/cloudingcity/golab/internal/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -11,7 +12,7 @@ var projectSearchCmd = &cobra.Command{
 	Short: "Search projects",
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
-			return &flagError{errors.New("requires a query")}
+			return &errs.ArgError{Err: errors.New("requires a query")}
 		}
 		return nil
 	},

cmd/root.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	conf "github.com/cloudingcity/golab/internal/config"
+	"github.com/cloudingcity/golab/internal/errors"
 	"github.com/cloudingcity/golab/internal/git"
 	"github.com/cloudingcity/golab/internal/gitlab/global"
 	"github.com/cloudingcity/golab/internal/gitlab/group"
@@ -27,14 +28,14 @@ var rootCmd = &cobra.Command{
 // Execute adds all child commands to the root command and sets flags appropriately.
 func Execute() {
 	if cmd, err := rootCmd.ExecuteC(); err != nil {
-		handleError(cmd, err)
+		errors.Handle(cmd, err)
 	}
 }
 
 func init() {
 	rootCmd.SetHelpCommand(&cobra.Command{Hidden: true})
 	rootCmd.SetFlagErrorFunc(func(cmd *cobra.Command, err error) error {
-		return &flagError{err}
+		return &errors.FlagError{Err: err}
 	})
 	cobra.OnInitialize(initConfig)
 

internal/errors/handler.go

@@ -0,0 +1,54 @@
+package errors
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+type FlagError struct {
+	Err error
+}
+
+func (e *FlagError) Error() string {
+	return e.Err.Error()
+}
+
+func (e *FlagError) Unwrap() error {
+	return e.Err
+}
+
+type ArgError struct {
+	Err error
+}
+
+func (e *ArgError) Error() string {
+	return e.Err.Error()
+}
+
+func (e *ArgError) Unwrap() error {
+	return e.Err
+}
+
+func Handle(cmd *cobra.Command, err error) {
+	fmt.Println(err)
+
+	var (
+		flagError *FlagError
+		argError  *ArgError
+	)
+	if errors.As(err, &flagError) || errors.As(err, &argError) || isUnknownCommand(err) || isDefaultFlagError(err) {
+		fmt.Println()
+		fmt.Println(cmd.UsageString())
+	}
+}
+
+func isUnknownCommand(err error) bool {
+	return strings.HasPrefix(err.Error(), "unknown command")
+}
+
+func isDefaultFlagError(err error) bool {
+	return strings.HasPrefix(err.Error(), "required flag")
+}

internal/errors/handler_test.go

@@ -0,0 +1,32 @@
+package errors
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsUnknownCommand(t *testing.T) {
+	err := errors.New("unknown command")
+
+	assert.True(t, isUnknownCommand(err))
+}
+
+func TestIsDefaultFlagError(t *testing.T) {
+	err := errors.New("required flag")
+
+	assert.True(t, isDefaultFlagError(err))
+}
+
+func ExampleHandle() {
+	cmd := &cobra.Command{}
+	err := &FlagError{Err: errors.New("something wrong")}
+
+	Handle(cmd, err)
+
+	// Output: something wrong
+	//
+	// Usage:
+}