cli-patterns

CLI Command Patterns

Reference patterns for implementing CLI commands in internal/cli/.

---

File Structure

internal/cli/{resource}/
├── {resource}.go      # Root command with New{Resource}Cmd()
├── list.go            # newListCmd()
├── show.go            # newShowCmd()
├── create.go          # newCreateCmd()
├── update.go          # newUpdateCmd()
├── delete.go          # newDeleteCmd()
├── helpers.go         # getClient(), getGrantID(), createContext()
└── {resource}_test.go # Unit tests

---

Root Command

package resource

import (
    "github.com/spf13/cobra"
)

// NewResourceCmd creates the resource command.
func NewResourceCmd() *cobra.Command {
    cmd := &cobra.Command{
        Use:   "resource",
        Short: "Manage resources",
        Long:  `Commands for managing resources in your Nylas account.`,
    }

    cmd.AddCommand(newListCmd())
    cmd.AddCommand(newShowCmd())
    cmd.AddCommand(newCreateCmd())
    cmd.AddCommand(newUpdateCmd())
    cmd.AddCommand(newDeleteCmd())

    return cmd
}

---

List Command

func newListCmd() *cobra.Command {
    var limit int
    var format string

    cmd := &cobra.Command{
        Use:   "list",
        Short: "List resources",
        Long:  `List all resources for the current grant.`,
        RunE: func(cmd *cobra.Command, args []string) error {
            ctx, cancel := createContext()
            defer cancel()

            client, err := getClient()
            if err != nil {
                return err
            }

            grantID, err := getGrantID()
            if err != nil {
                return err
            }

            params := &domain.ResourceQueryParams{
                Limit: limit,
            }

            resources, err := client.GetResources(ctx, grantID, params)
            if err != nil {
                return fmt.Errorf("failed to list resources: %w", err)
            }

            return outputResources(resources, format)
        },
    }

    cmd.Flags().IntVarP(&limit, "limit", "l", 50, "Maximum number of resources to return")
    cmd.Flags().StringVarP(&format, "format", "f", "table", "Output format (table, json, yaml)")

    return cmd
}