Merge pull request #2353 from alissonbrunosa/refactoring-custom-error-messages

[Cosmetic] Extract duplicated code to a reusable function

pkg/cmd/pr/checkout/checkout.go

@@ -1,7 +1,6 @@
 package checkout
 
 import (
-	"errors"
 	"fmt"
 	"net/http"
 	"os"
@@ -44,12 +43,7 @@ func NewCmdCheckout(f *cmdutil.Factory, runF func(*CheckoutOptions) error) *cobr
 	cmd := &cobra.Command{
 		Use:   "checkout {<number> | <url> | <branch>}",
 		Short: "Check out a pull request in git",
-		Args: func(cmd *cobra.Command, args []string) error {
-			if len(args) == 0 {
-				return &cmdutil.FlagError{Err: errors.New("argument required")}
-			}
-			return nil
-		},
+		Args:  cmdutil.MinimumArgs(1, "argument required"),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			// support `-R, --repo` override
 			opts.BaseRepo = f.BaseRepo

pkg/cmd/release/create/create.go

@@ -2,7 +2,6 @@ package create
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -77,13 +76,7 @@ func NewCmdCreate(f *cmdutil.Factory, runF func(*CreateOptions) error) *cobra.Co
 			# upload a release asset with a display label
 			$ gh release create v1.2.3 '/path/to/asset.zip#My display label'
 		`),
-		Args: func(cmd *cobra.Command, args []string) error {
-			if len(args) > 0 {
-				return nil
-			}
-
-			return &cmdutil.FlagError{Err: errors.New("could not create: no tag name provided")}
-		},
+		Args: cmdutil.MinimumArgs(1, "could not create: no tag name provided"),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			// support `-R, --repo` override
 			opts.BaseRepo = f.BaseRepo

pkg/cmd/repo/clone/clone.go

@@ -1,7 +1,6 @@
 package clone
 
 import (
-	"errors"
 	"fmt"
 	"net/http"
 	"strings"
@@ -37,13 +36,8 @@ func NewCmdClone(f *cmdutil.Factory, runF func(*CloneOptions) error) *cobra.Comm
 	cmd := &cobra.Command{
 		DisableFlagsInUseLine: true,
 
-		Use: "clone <repository> [<directory>] [-- <gitflags>...]",
-		Args: func(cmd *cobra.Command, args []string) error {
-			if len(args) == 0 {
-				return &cmdutil.FlagError{Err: errors.New("cannot clone: repository argument required")}
-			}
-			return nil
-		},
+		Use:   "clone <repository> [<directory>] [-- <gitflags>...]",
+		Args:  cmdutil.MinimumArgs(1, "cannot clone: repository argument required"),
 		Short: "Clone a repository locally",
 		Long: heredoc.Doc(`
 			Clone a GitHub repository locally.

pkg/cmdutil/args.go

@@ -8,6 +8,19 @@ import (
 	"github.com/spf13/pflag"
 )
 
+func MinimumArgs(n int, msg string) cobra.PositionalArgs {
+	if msg == "" {
+		return cobra.MinimumNArgs(1)
+	}
+
+	return func(cmd *cobra.Command, args []string) error {
+		if len(args) < n {
+			return &FlagError{Err: errors.New(msg)}
+		}
+		return nil
+	}
+}
+
 func NoArgsQuoteReminder(cmd *cobra.Command, args []string) error {
 	if len(args) < 1 {
 		return nil

pkg/cmdutil/args_test.go

@@ -0,0 +1,50 @@
+package cmdutil
+
+import "testing"
+
+func TestMinimumArgs(t *testing.T) {
+	tests := []struct {
+		N    int
+		Args []string
+	}{
+		{
+			N:    1,
+			Args: []string{"v1.2.3"},
+		},
+		{
+			N:    2,
+			Args: []string{"v1.2.3", "cli/cli"},
+		},
+	}
+
+	for _, test := range tests {
+		if got := MinimumArgs(test.N, "")(nil, test.Args); got != nil {
+			t.Errorf("Got: %v, Want: (nil)", got)
+		}
+	}
+}
+
+func TestMinimumNs_with_error(t *testing.T) {
+	tests := []struct {
+		N             int
+		CustomMessage string
+		WantMessage   string
+	}{
+		{
+			N:             1,
+			CustomMessage: "A custom msg",
+			WantMessage:   "A custom msg",
+		},
+		{
+			N:             1,
+			CustomMessage: "",
+			WantMessage:   "requires at least 1 arg(s), only received 0",
+		},
+	}
+
+	for _, test := range tests {
+		if got := MinimumArgs(test.N, test.CustomMessage)(nil, nil); got.Error() != test.WantMessage {
+			t.Errorf("Got: %v, Want: %v", got, test.WantMessage)
+		}
+	}
+}