Added option to specify branch in gh repo view

pkg/cmd/repo/view/http.go

@@ -17,14 +17,14 @@ type RepoReadme struct {
 	Content  string
 }
 
-func RepositoryReadme(client *http.Client, repo ghrepo.Interface) (*RepoReadme, error) {
+func RepositoryReadme(client *http.Client, repo ghrepo.Interface, branch string) (*RepoReadme, error) {
 	apiClient := api.NewClientFromHTTP(client)
 	var response struct {
 		Name    string
 		Content string
 	}
 
-	err := apiClient.REST(repo.RepoHost(), "GET", fmt.Sprintf("repos/%s/readme", ghrepo.FullName(repo)), nil, &response)
+	err := apiClient.REST(repo.RepoHost(), "GET", getReadmePath(repo, branch), nil, &response)
 	if err != nil {
 		var httpError api.HTTPError
 		if errors.As(err, &httpError) && httpError.StatusCode == 404 {
@@ -43,3 +43,11 @@ func RepositoryReadme(client *http.Client, repo ghrepo.Interface) (*RepoReadme,
 		Content:  string(decoded),
 	}, nil
 }
+
+func getReadmePath(repo ghrepo.Interface, branch string) string {
+	path := fmt.Sprintf("repos/%s/readme", ghrepo.FullName(repo))
+	if branch != "" {
+		path = fmt.Sprintf("%s?ref=%s", path, branch)
+	}
+	return path
+}

pkg/cmd/repo/view/view.go

@@ -25,6 +25,7 @@ type ViewOptions struct {
 
 	RepoArg string
 	Web     bool
+	Branch  string
 }
 
 func NewCmdView(f *cmdutil.Factory, runF func(*ViewOptions) error) *cobra.Command {
@@ -41,7 +42,9 @@ func NewCmdView(f *cmdutil.Factory, runF func(*ViewOptions) error) *cobra.Comman
 
 With no argument, the repository for the current directory is displayed.
 
-With '--web', open the repository in a web browser instead.`,
+With '--web', open the repository in a web browser instead.
+
+With '--branch', view a specific branch of the repository.`,
 		Args: cobra.MaximumNArgs(1),
 		RunE: func(c *cobra.Command, args []string) error {
 			if len(args) > 0 {
@@ -55,6 +58,7 @@ With '--web', open the repository in a web browser instead.`,
 	}
 
 	cmd.Flags().BoolVarP(&opts.Web, "web", "w", false, "Open a repository in the browser")
+	cmd.Flags().StringVarP(&opts.Branch, "branch", "b", "", "View a specific branch of the repository")
 
 	return cmd
 }
@@ -104,7 +108,7 @@ func viewRun(opts *ViewOptions) error {
 
 	fullName := ghrepo.FullName(toView)
 
-	readme, err := RepositoryReadme(httpClient, toView)
+	readme, err := RepositoryReadme(httpClient, toView, opts.Branch)
 	if err != nil && err != NotFoundError {
 		return err
 	}

pkg/cmd/repo/view/view_test.go

@@ -47,6 +47,14 @@ func TestNewCmdView(t *testing.T) {
 				Web:     true,
 			},
 		},
+		{
+			name: "sets branch",
+			cli:  "-b feat/awesome",
+			wants: ViewOptions{
+				RepoArg: "",
+				Branch:  "feat/awesome",
+			},
+		},
 	}
 
 	for _, tt := range tests {
@@ -80,6 +88,7 @@ func TestNewCmdView(t *testing.T) {
 			assert.NoError(t, err)
 
 			assert.Equal(t, tt.wants.Web, gotOpts.Web)
+			assert.Equal(t, tt.wants.Branch, gotOpts.Branch)
 			assert.Equal(t, tt.wants.RepoArg, gotOpts.RepoArg)
 		})
 	}
@@ -198,6 +207,24 @@ func Test_ViewRun(t *testing.T) {
 				View this repository on GitHub: https://github.com/jill/valentine
 			`),
 		},
+		{
+			name: "branch arg",
+			opts: &ViewOptions{
+				Branch: "feat/awesome",
+			},
+			stdoutTTY: true,
+			wantOut: heredoc.Doc(`
+				OWNER/REPO
+				social distancing
+
+
+				  # truly cool readme check it out                                            
+
+
+
+				View this repository on GitHub: https://github.com/OWNER/REPO
+			`),
+		},
 		{
 			name:      "no args",
 			stdoutTTY: true,