Merge pull request #103 from JunNishimura/#102

add switch command

cmd/switch.go

@@ -0,0 +1,63 @@
+/*
+Copyright © 2023 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	createOption string
+)
+
+// switchCmd represents the switch command
+var switchCmd = &cobra.Command{
+	Use:   "switch",
+	Short: "switch branches",
+	Long:  "switch branches",
+	PreRunE: func(cmd *cobra.Command, args []string) error {
+		if client.RootGoitPath == "" {
+			return ErrGoitNotInitialized
+		}
+		return nil
+	},
+	RunE: func(cmd *cobra.Command, args []string) error {
+		// validation
+		if len(args) >= 2 {
+			return errors.New("fatal: only one reference expected")
+		}
+		if createOption == "" && len(args) == 0 {
+			return errors.New("fatal: missing branch")
+		} else if createOption != "" && len(args) >= 1 {
+			return errors.New("invalid create option format")
+		}
+
+		// switch branch == update HEAD
+		if len(args) == 1 {
+			if err := client.Head.Update(client.Refs, client.RootGoitPath, args[0]); err != nil {
+				return fmt.Errorf("fail to update HEAD: %w", err)
+			}
+		}
+
+		if createOption != "" {
+			if err := client.Refs.AddBranch(client.RootGoitPath, createOption, client.Head.Commit.Hash); err != nil {
+				return fmt.Errorf("fail to create new branch %s: %w", createOption, err)
+			}
+			if err := client.Head.Update(client.Refs, client.RootGoitPath, createOption); err != nil {
+				return fmt.Errorf("fail to update HEAD: %w", err)
+			}
+		}
+
+		return nil
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(switchCmd)
+
+	switchCmd.Flags().StringVarP(&createOption, "create", "c", "", "create new branch")
+}

internal/store/head.go

@@ -85,7 +85,13 @@ func newHead() *Head {
 	return &Head{}
 }
 
-func (h *Head) Update(rootGoitPath, newRef string) error {
+func (h *Head) Update(refs *Refs, rootGoitPath, newRef string) error {
+	// check if branch exists
+	n := refs.getBranchPos(newRef)
+	if n == NewBranchFlag {
+		return fmt.Errorf("branch %s does not exist", newRef)
+	}
+
 	headPath := filepath.Join(rootGoitPath, "HEAD")
 	if _, err := os.Stat(headPath); os.IsNotExist(err) {
 		return errors.New("fail to find HEAD, cannot update")

internal/store/refs.go

@@ -134,7 +134,7 @@ func (r *Refs) RenameBranch(head *Head, rootGoitPath, newBranchName string) erro
 	}
 
 	// update HEAD
-	if err := head.Update(rootGoitPath, newBranchName); err != nil {
+	if err := head.Update(r, rootGoitPath, newBranchName); err != nil {
 		return fmt.Errorf("fail to update HEAD: %w", err)
 	}