Autocomplete branch flags (#6031)

Co-authored-by: Mislav Marohnić <mislav@github.com>

git/client.go

@@ -354,6 +354,22 @@ func (c *Client) HasLocalBranch(ctx context.Context, branch string) bool {
 	return err == nil
 }
 
+func (c *Client) TrackingBranchNames(ctx context.Context, prefix string) []string {
+	args := []string{"branch", "-r", "--format", "%(refname:strip=3)"}
+	if prefix != "" {
+		args = append(args, "--list", fmt.Sprintf("*/%s*", escapeGlob(prefix)))
+	}
+	cmd, err := c.Command(ctx, args...)
+	if err != nil {
+		return nil
+	}
+	output, err := cmd.Output()
+	if err != nil {
+		return nil
+	}
+	return strings.Split(string(output), "\n")
+}
+
 // ToplevelDir returns the top-level directory path of the current repository.
 func (c *Client) ToplevelDir(ctx context.Context) (string, error) {
 	out, err := c.revParse(ctx, "--show-toplevel")
@@ -623,3 +639,16 @@ func populateResolvedRemotes(remotes RemoteSet, resolved []string) {
 		}
 	}
 }
+
+var globReplacer = strings.NewReplacer(
+	"*", `\*`,
+	"?", `\?`,
+	"[", `\[`,
+	"]", `\]`,
+	"{", `\{`,
+	"}", `\}`,
+)
+
+func escapeGlob(p string) string {
+	return globReplacer.Replace(p)
+}

pkg/cmd/browse/browse.go

@@ -144,6 +144,8 @@ func NewCmdBrowse(f *cmdutil.Factory, runF func(*BrowseOptions) error) *cobra.Co
 	cmd.Flags().StringVarP(&opts.Commit, "commit", "c", "", "Select another commit by passing in the commit SHA, default is the last commit")
 	cmd.Flags().StringVarP(&opts.Branch, "branch", "b", "", "Select another branch by passing in the branch name")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "branch")
+
 	// Preserve backwards compatibility for when commit flag used to be a boolean flag.
 	cmd.Flags().Lookup("commit").NoOptDefVal = emptyCommitFlag
 

pkg/cmd/pr/create/create.go

@@ -189,6 +189,8 @@ func NewCmdCreate(f *cmdutil.Factory, runF func(*CreateOptions) error) *cobra.Co
 	fl.StringVar(&opts.RecoverFile, "recover", "", "Recover input from a failed run of create")
 	fl.StringVarP(&opts.Template, "template", "T", "", "Template `file` to use as starting body text")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "base", "head")
+
 	_ = cmd.RegisterFlagCompletionFunc("reviewer", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 		results, err := requestableReviewersForCompletion(opts)
 		if err != nil {

pkg/cmd/pr/edit/edit.go

@@ -148,6 +148,8 @@ func NewCmdEdit(f *cmdutil.Factory, runF func(*EditOptions) error) *cobra.Comman
 	cmd.Flags().StringSliceVar(&opts.Editable.Projects.Remove, "remove-project", nil, "Remove the pull request from projects by `name`")
 	cmd.Flags().StringVarP(&opts.Editable.Milestone.Value, "milestone", "m", "", "Edit the milestone the pull request belongs to by `name`")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "base")
+
 	for _, flagName := range []string{"add-reviewer", "remove-reviewer"} {
 		_ = cmd.RegisterFlagCompletionFunc(flagName, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 			baseRepo, err := f.BaseRepo()

pkg/cmd/pr/list/list.go

@@ -109,9 +109,10 @@ func NewCmdList(f *cmdutil.Factory, runF func(*ListOptions) error) *cobra.Comman
 	cmd.Flags().StringVarP(&opts.Assignee, "assignee", "a", "", "Filter by assignee")
 	cmd.Flags().StringVarP(&opts.Search, "search", "S", "", "Search pull requests with `query`")
 	cmdutil.NilBoolFlag(cmd, &opts.Draft, "draft", "d", "Filter by draft state")
-
 	cmdutil.AddJSONFlags(cmd, &opts.Exporter, api.PullRequestFields)
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "base", "head")
+
 	return cmd
 }
 

pkg/cmd/release/create/create.go

@@ -177,6 +177,8 @@ func NewCmdCreate(f *cmdutil.Factory, runF func(*CreateOptions) error) *cobra.Co
 	cmdutil.NilBoolFlag(cmd, &opts.IsLatest, "latest", "", "Mark this release as \"Latest\" (default: automatic based on date and version)")
 	cmd.Flags().BoolVarP(&opts.VerifyTag, "verify-tag", "", false, "Abort in case the git tag doesn't already exist in the remote repository")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "target")
+
 	return cmd
 }
 

pkg/cmd/release/edit/edit.go

@@ -82,6 +82,8 @@ func NewCmdEdit(f *cmdutil.Factory, runF func(*EditOptions) error) *cobra.Comman
 	cmd.Flags().StringVar(&opts.TagName, "tag", "", "The name of the tag")
 	cmd.Flags().StringVarP(&notesFile, "notes-file", "F", "", "Read release notes from `file` (use \"-\" to read from standard input)")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "target")
+
 	return cmd
 }
 

pkg/cmd/repo/view/view.go

@@ -68,6 +68,8 @@ With '--branch', view a specific branch of the repository.`,
 	cmd.Flags().StringVarP(&opts.Branch, "branch", "b", "", "View a specific branch of the repository")
 	cmdutil.AddJSONFlags(cmd, &opts.Exporter, api.RepositoryFields)
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "branch")
+
 	return cmd
 }
 

pkg/cmd/run/list/list.go

@@ -69,6 +69,8 @@ func NewCmdList(f *cmdutil.Factory, runF func(*ListOptions) error) *cobra.Comman
 	cmd.Flags().StringVarP(&opts.Actor, "user", "u", "", "Filter runs by user who triggered the run")
 	cmdutil.AddJSONFlags(cmd, &opts.Exporter, shared.RunFields)
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "branch")
+
 	return cmd
 }
 

pkg/cmd/search/prs/prs.go

@@ -184,5 +184,7 @@ func NewCmdPrs(f *cmdutil.Factory, runF func(*shared.IssuesOptions) error) *cobr
 	cmd.Flags().StringVar(&opts.Query.Qualifiers.ReviewedBy, "reviewed-by", "", "Filter on `user` who reviewed")
 	cmdutil.StringEnumFlag(cmd, &opts.Query.Qualifiers.Status, "checks", "", "", []string{"pending", "success", "failure"}, "Filter based on status of the checks")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "base", "head")
+
 	return cmd
 }

pkg/cmd/workflow/run/run.go

@@ -128,6 +128,8 @@ func NewCmdRun(f *cmdutil.Factory, runF func(*RunOptions) error) *cobra.Command
 	cmd.Flags().StringArrayVarP(&opts.RawFields, "raw-field", "f", nil, "Add a string parameter in `key=value` format")
 	cmd.Flags().BoolVar(&opts.JSON, "json", false, "Read workflow inputs as JSON via STDIN")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "ref")
+
 	return cmd
 }
 

pkg/cmd/workflow/view/view.go

@@ -85,6 +85,8 @@ func NewCmdView(f *cmdutil.Factory, runF func(*ViewOptions) error) *cobra.Comman
 	cmd.Flags().BoolVarP(&opts.YAML, "yaml", "y", false, "View the workflow yaml file")
 	cmd.Flags().StringVarP(&opts.Ref, "ref", "r", "", "The branch or tag name which contains the version of the workflow file you'd like to view")
 
+	_ = cmdutil.RegisterBranchCompletionFlags(f.GitClient, cmd, "ref")
+
 	return cmd
 }
 

pkg/cmdutil/flags.go

@@ -1,6 +1,7 @@
 package cmdutil
 
 import (
+	"context"
 	"fmt"
 	"strconv"
 	"strings"
@@ -44,6 +45,26 @@ func StringSliceEnumFlag(cmd *cobra.Command, p *[]string, name, shorthand string
 	return f
 }
 
+type gitClient interface {
+	TrackingBranchNames(context.Context, string) []string
+}
+
+// RegisterBranchCompletionFlags suggests and autocompletes known remote git branches for flags passed
+func RegisterBranchCompletionFlags(gitc gitClient, cmd *cobra.Command, flags ...string) error {
+	for _, flag := range flags {
+		err := cmd.RegisterFlagCompletionFunc(flag, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if repoFlag := cmd.Flag("repo"); repoFlag != nil && repoFlag.Changed {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			return gitc.TrackingBranchNames(context.TODO(), toComplete), cobra.ShellCompDirectiveNoFileComp
+		})
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func formatValuesForUsageDocs(values []string) string {
 	return fmt.Sprintf("{%s}", strings.Join(values, "|"))
 }