Add pr show command

command/pr.go

@@ -2,6 +2,7 @@ package command
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 
 	"github.com/github/gh-cli/api"
@@ -12,7 +13,18 @@ import (
 
 func init() {
 	RootCmd.AddCommand(prCmd)
-	prCmd.AddCommand(prListCmd)
+	prCmd.AddCommand(
+		&cobra.Command{
+			Use:   "list",
+			Short: "List pull requests",
+			RunE:  prList,
+		},
+		&cobra.Command{
+			Use:   "view",
+			Short: "Open the pull request in the browser",
+			RunE:  prShow,
+		},
+	)
 }
 
 var prCmd = &cobra.Command{
@@ -26,15 +38,7 @@ work with pull requests.`,
 	},
 }
 
-var prListCmd = &cobra.Command{
-	Use:   "list",
-	Short: "List pull requests",
-	RunE: func(cmd *cobra.Command, args []string) error {
-		return ExecutePr()
-	},
-}
-
-func ExecutePr() error {
+func prList(cmd *cobra.Command, args []string) error {
 	prPayload, err := api.PullRequests()
 	if err != nil {
 		return err
@@ -68,6 +72,27 @@ func ExecutePr() error {
 	return nil
 }
 
+func show(cmd *cobra.Command, args []string) error {
+	project := project()
+
+	var openURL string
+	if len(number) > 0 {
+		if prNumber, err := strconv.Atoi(number[0]); err == nil {
+			openURL = project.WebURL("", "", fmt.Sprintf("pull/%d", prNumber))
+		} else {
+			return fmt.Errorf("invalid pull request number: '%s'", number[0])
+		}
+	} else {
+		pr, err := pullRequestForCurrentBranch()
+		if err != nil {
+			return err
+		}
+		openURL = pr.HtmlUrl
+	}
+
+	return openInBrowser(openURL)
+}
+
 func printPrs(prs ...api.PullRequest) {
 	for _, pr := range prs {
 		fmt.Printf("  #%d %s [%s]\n", pr.Number, truncateTitle(pr.Title), aurora.Cyan(pr.HeadRefName))