Add --reviewer flag completion (#6873)

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

pkg/cmd/pr/create/create.go

@@ -182,6 +182,14 @@ func NewCmdCreate(f *cmdutil.Factory, runF func(*CreateOptions) error) *cobra.Co
 	fl.Bool("no-maintainer-edit", false, "Disable maintainer's ability to modify pull request")
 	fl.StringVar(&opts.RecoverFile, "recover", "", "Recover input from a failed run of create")
 
+	_ = cmd.RegisterFlagCompletionFunc("reviewer", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		results, err := requestableReviewersForCompletion(opts)
+		if err != nil {
+			return nil, cobra.ShellCompDirectiveError
+		}
+		return results, cobra.ShellCompDirectiveNoFileComp
+	})
+
 	return cmd
 }
 
@@ -472,16 +480,10 @@ func NewCreateContext(opts *CreateOptions) (*CreateContext, error) {
 	}
 	client := api.NewClientFromHTTP(httpClient)
 
-	// TODO: consider obtaining remotes from GitClient instead
-	remotes, err := opts.Remotes()
+	remotes, err := getRemotes(opts)
 	if err != nil {
-		// When a repo override value is given, ignore errors when fetching git remotes
-		// to support using this command outside of git repos.
-		if opts.RepoOverride == "" {
-			return nil, err
-		}
+		return nil, err
 	}
-
 	repoContext, err := ghContext.ResolveRemotesToRepos(remotes, client, opts.RepoOverride)
 	if err != nil {
 		return nil, err
@@ -628,6 +630,19 @@ func NewCreateContext(opts *CreateOptions) (*CreateContext, error) {
 
 }
 
+func getRemotes(opts *CreateOptions) (ghContext.Remotes, error) {
+	// TODO: consider obtaining remotes from GitClient instead
+	remotes, err := opts.Remotes()
+	if err != nil {
+		// When a repo override value is given, ignore errors when fetching git remotes
+		// to support using this command outside of git repos.
+		if opts.RepoOverride == "" {
+			return nil, err
+		}
+	}
+	return remotes, nil
+}
+
 func submitPR(opts CreateOptions, ctx CreateContext, state shared.IssueMetadataState) error {
 	client := ctx.Client
 
@@ -782,4 +797,26 @@ func humanize(s string) string {
 	return strings.Map(h, s)
 }
 
+func requestableReviewersForCompletion(opts *CreateOptions) ([]string, error) {
+	httpClient, err := opts.HttpClient()
+	if err != nil {
+		return nil, err
+	}
+
+	remotes, err := getRemotes(opts)
+	if err != nil {
+		return nil, err
+	}
+	repoContext, err := ghContext.ResolveRemotesToRepos(remotes, api.NewClientFromHTTP(httpClient), opts.RepoOverride)
+	if err != nil {
+		return nil, err
+	}
+	baseRepo, err := repoContext.BaseRepo(opts.IO)
+	if err != nil {
+		return nil, err
+	}
+
+	return shared.RequestableReviewersForCompletion(httpClient, baseRepo)
+}
+
 var gitPushRegexp = regexp.MustCompile("^remote: (Create a pull request.*by visiting|[[:space:]]*https://.*/pull/new/).*\n?$")

pkg/cmd/pr/edit/edit.go

@@ -148,6 +148,24 @@ 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`")
 
+	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()
+			if err != nil {
+				return nil, cobra.ShellCompDirectiveError
+			}
+			httpClient, err := f.HttpClient()
+			if err != nil {
+				return nil, cobra.ShellCompDirectiveError
+			}
+			results, err := shared.RequestableReviewersForCompletion(httpClient, baseRepo)
+			if err != nil {
+				return nil, cobra.ShellCompDirectiveError
+			}
+			return results, cobra.ShellCompDirectiveNoFileComp
+		})
+	}
+
 	return cmd
 }
 

pkg/cmd/pr/shared/completion.go

@@ -0,0 +1,39 @@
+package shared
+
+import (
+	"fmt"
+	"net/http"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/cli/cli/v2/api"
+	"github.com/cli/cli/v2/internal/ghrepo"
+)
+
+func RequestableReviewersForCompletion(httpClient *http.Client, repo ghrepo.Interface) ([]string, error) {
+	client := api.NewClientFromHTTP(api.NewCachedHTTPClient(httpClient, time.Minute*2))
+
+	metadata, err := api.RepoMetadata(client, repo, api.RepoMetadataInput{Reviewers: true})
+	if err != nil {
+		return nil, err
+	}
+
+	results := []string{}
+	for _, user := range metadata.AssignableUsers {
+		if strings.EqualFold(user.Login, metadata.CurrentLogin) {
+			continue
+		}
+		if user.Name != "" {
+			results = append(results, fmt.Sprintf("%s\t%s", user.Login, user.Name))
+		} else {
+			results = append(results, user.Login)
+		}
+	}
+	for _, team := range metadata.Teams {
+		results = append(results, fmt.Sprintf("%s/%s", repo.RepoOwner(), team.Slug))
+	}
+
+	sort.Strings(results)
+	return results, nil
+}