add delete branch (#98)

cmd/branch.go

@@ -58,6 +58,29 @@ func rename(client *store.Client, newName string) error {
 	return nil
 }
 
+func delete(client *store.Client, branchName string) error {
+	// branch validation
+	if branchName == client.Head.Reference {
+		return fmt.Errorf("error: cannot delete current branch '%s'", client.Head.Reference)
+	}
+	isBranchFound := false
+	for _, branch := range client.Refs.Heads {
+		if branch.Name == branchName {
+			isBranchFound = true
+		}
+	}
+	if !isBranchFound {
+		return fmt.Errorf("error: branch '%s' not found", branchName)
+	}
+
+	// delete branch
+	if err := client.Refs.DeleteBranch(client.RootGoitPath, branchName); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // branchCmd represents the branch command
 var branchCmd = &cobra.Command{
 	Use:   "branch",
@@ -93,6 +116,12 @@ var branchCmd = &cobra.Command{
 			}
 		}
 
+		if deleteOption != "" {
+			if err := delete(client, deleteOption); err != nil {
+				return err
+			}
+		}
+
 		return nil
 	},
 }

internal/store/refs.go

@@ -68,3 +68,29 @@ func (r *Refs) GetBranch(name string) (*branch, error) {
 	}
 	return nil, fmt.Errorf("fail to find '%s' branch", name)
 }
+
+func getBranchPos(branches []*branch, name string) (int, bool) {
+	for n, branch := range branches {
+		if branch.Name == name {
+			return n, true
+		}
+	}
+	return -1, false
+}
+
+func (r *Refs) DeleteBranch(rootGoitPath, name string) error {
+	// delete branch from Refs
+	p, isBranchFound := getBranchPos(r.Heads, name)
+	if !isBranchFound {
+		return fmt.Errorf("branch '%s' not found", name)
+	}
+	r.Heads = append(r.Heads[:p], r.Heads[p+1:]...)
+
+	// delete branch file
+	branchPath := filepath.Join(rootGoitPath, "refs", "heads", name)
+	if err := os.Remove(branchPath); err != nil {
+		return err
+	}
+
+	return nil
+}