Add repo clone <repo> command

command/repo.go

@@ -2,8 +2,10 @@ package command
 
 import (
 	"fmt"
+	"os"
 	"strings"
 
+	"github.com/cli/cli/git"
 	"github.com/cli/cli/internal/ghrepo"
 	"github.com/cli/cli/utils"
 	"github.com/spf13/cobra"
@@ -11,6 +13,7 @@ import (
 
 func init() {
 	RootCmd.AddCommand(repoCmd)
+	repoCmd.AddCommand(repoCloneCmd)
 	repoCmd.AddCommand(repoViewCmd)
 }
 
@@ -24,6 +27,16 @@ A repository can be supplied as an argument in any of the following formats:
 - by URL, e.g. "https://github.com/OWNER/REPO"`,
 }
 
+var repoCloneCmd = &cobra.Command{
+	Use:   "clone <repo>",
+	Args:  cobra.MinimumNArgs(1),
+	Short: "Clone a repository locally",
+	Long: `Clone a GitHub repository locally.
+
+To pass 'git clone' options, separate them with '--'.`,
+	RunE: repoClone,
+}
+
 var repoViewCmd = &cobra.Command{
 	Use:   "view [<repo>]",
 	Short: "View a repository in the browser",
@@ -33,6 +46,23 @@ With no argument, the repository for the current directory is opened.`,
 	RunE: repoView,
 }
 
+func repoClone(cmd *cobra.Command, args []string) error {
+	cloneURL := args[0]
+	if !strings.Contains(cloneURL, ":") {
+		cloneURL = fmt.Sprintf("https://github.com/%s.git", cloneURL)
+	}
+
+	cloneArgs := []string{"clone"}
+	cloneArgs = append(cloneArgs, args[1:]...)
+	cloneArgs = append(cloneArgs, cloneURL)
+
+	cloneCmd := git.GitCommand(cloneArgs...)
+	cloneCmd.Stdin = os.Stdin
+	cloneCmd.Stdout = os.Stdout
+	cloneCmd.Stderr = os.Stderr
+	return utils.PrepareCmd(cloneCmd).Run()
+}
+
 func repoView(cmd *cobra.Command, args []string) error {
 	ctx := contextForCommand(cmd)
 

command/repo_test.go

@@ -2,12 +2,65 @@ package command
 
 import (
 	"os/exec"
+	"strings"
 	"testing"
 
 	"github.com/cli/cli/context"
 	"github.com/cli/cli/utils"
 )
 
+func TestRepoClone(t *testing.T) {
+	tests := []struct {
+		name string
+		args string
+		want string
+	}{
+		{
+			name: "shorthand",
+			args: "repo clone OWNER/REPO",
+			want: "git clone https://github.com/OWNER/REPO.git",
+		},
+		{
+			name: "clone arguments",
+			args: "repo clone OWNER/REPO -- -o upstream --depth 1",
+			want: "git clone -o upstream --depth 1 https://github.com/OWNER/REPO.git",
+		},
+		{
+			name: "HTTPS URL",
+			args: "repo clone https://github.com/OWNER/REPO",
+			want: "git clone https://github.com/OWNER/REPO",
+		},
+		{
+			name: "SSH URL",
+			args: "repo clone git@github.com:OWNER/REPO.git",
+			want: "git clone git@github.com:OWNER/REPO.git",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var seenCmd *exec.Cmd
+			restoreCmd := utils.SetPrepareCmd(func(cmd *exec.Cmd) utils.Runnable {
+				seenCmd = cmd
+				return &outputStub{}
+			})
+			defer restoreCmd()
+
+			output, err := RunCommand(repoViewCmd, tt.args)
+			if err != nil {
+				t.Fatalf("error running command `repo clone`: %v", err)
+			}
+
+			eq(t, output.String(), "")
+			eq(t, output.Stderr(), "")
+
+			if seenCmd == nil {
+				t.Fatal("expected a command to run")
+			}
+			eq(t, strings.Join(seenCmd.Args, " "), tt.want)
+		})
+	}
+}
+
 func TestRepoView(t *testing.T) {
 	initBlankContext("OWNER/REPO", "master")
 	http := initFakeHTTP()