feat(branches): add rename subcommand (#939)

Implements the 'branches rename' command to rename a branch in a repository.
This wraps the Gitea API endpoint PATCH /repos/{owner}/{repo}/branches/{branch}.

Usage: tea branches rename <old_branch_name> <new_branch_name>

Example: tea branches rename -r owner/repo main factory

This resolves issue #938.

Reviewed-on: https://gitea.com/gitea/tea/pulls/939
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Matěj Cepl <mcepl@cepl.eu>
Co-committed-by: Matěj Cepl <mcepl@cepl.eu>

cmd/branches/rename.go

@@ -0,0 +1,78 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package branches
+
+import (
+	stdctx "context"
+	"fmt"
+
+	"code.gitea.io/tea/cmd/flags"
+	"code.gitea.io/tea/modules/context"
+
+	"code.gitea.io/sdk/gitea"
+	"github.com/urfave/cli/v3"
+)
+
+// CmdBranchesRenameFlags Flags for command rename
+var CmdBranchesRenameFlags = append([]cli.Flag{
+	branchFieldsFlag,
+	&flags.PaginationPageFlag,
+	&flags.PaginationLimitFlag,
+}, flags.AllDefaultFlags...)
+
+// CmdBranchesRename represents a sub command of branches to rename a branch
+var CmdBranchesRename = cli.Command{
+	Name:        "rename",
+	Aliases:     []string{"rn"},
+	Usage:       "Rename a branch",
+	Description: `Rename a branch in a repository`,
+	ArgsUsage:   "<old_branch_name> <new_branch_name>",
+	Action:      RunBranchesRename,
+	Flags:       CmdBranchesRenameFlags,
+}
+
+// RunBranchesRename function to rename a branch
+func RunBranchesRename(_ stdctx.Context, cmd *cli.Command) error {
+	ctx, err := context.InitCommand(cmd)
+	if err != nil {
+		return err
+	}
+	if err := ctx.Ensure(context.CtxRequirement{RemoteRepo: true}); err != nil {
+		return err
+	}
+
+	if err := ValidateRenameArgs(ctx.Args().Slice()); err != nil {
+		return err
+	}
+
+	oldBranchName := ctx.Args().Get(0)
+	newBranchName := ctx.Args().Get(1)
+
+	owner := ctx.Owner
+	if ctx.IsSet("owner") {
+		owner = ctx.String("owner")
+	}
+
+	successful, _, err := ctx.Login.Client().RenameRepoBranch(owner, ctx.Repo, oldBranchName, gitea.RenameRepoBranchOption{
+		Name: newBranchName,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to rename branch: %w", err)
+	}
+	if !successful {
+		return fmt.Errorf("failed to rename branch")
+	}
+
+	fmt.Printf("Successfully renamed branch '%s' to '%s'\n", oldBranchName, newBranchName)
+
+	return nil
+}
+
+// ValidateRenameArgs validates arguments for the rename command
+func ValidateRenameArgs(args []string) error {
+	if len(args) != 2 {
+		return fmt.Errorf("must specify exactly two arguments: <old_branch_name> <new_branch_name>")
+	}
+	return nil
+}