commander

# Commander.js v14 ## 基本設定 ```ts import { Command } from "commander"; const program = new Command() .name("my-cli") .description("CLI description") .version("1.0.0"); ``` ## Options ```ts program .option("-d, --debug", "debug mode") // boolean .option("-p, --port <number>", "port", parseInt) // required value + parser .option("-c, --config [path]", "config file") // optional value .requiredOption("-u, --user <name>", "user"); // mandatory ``` ## Subcommands ```ts program .command("serve") .description("start server") .argument("[root]", "project root", ".") .option("-p, --port <number>", "port", parseInt) .action(async (root, options) => { console.log(`Serving ${root} on ${options.port}`); }); await program.parseAsync(); ``` ## 共用 Options ```ts function addSharedOptions(cmd: Command) { return cmd .option("-c, --country <code>", "country code") .option("-l, --limit <number>", "limit", parseInt); } addSharedOptions(program.command("collect")).action(async (opts) => { ... }); addSharedOptions(program.command("generate")).action(async (opts) => { ... }); ``` ## Async Action 用 `parseAsync()` 取代 `parse()`： ```ts program.command("fetch").action(async () => { await fetchData(); }); await program.parseAsync(); ``` ## 錯誤處理 ```ts import { InvalidArgumentError } from "commander"; function myParseInt(value: string): number { const n = parseInt(value, 10); if (isNaN(n)) throw new InvalidArgumentError("Not a number"); return n; } ``` ## Hooks ```ts program .hook("preAction", (_, cmd) => console.log(`Running: ${cmd.name()}`)) .hook("postAction", (_, cmd) => console.log(`Done: ${cmd.name()}`)); ``` ## TypeScript 強型別 安裝 `@commander-js/extra-typings` 可自動推導 `opts()` 型別。 ## 常用模式 | 模式 | 做法 | |------|------| | 顯示 help on error | `program.showHelpAfterError()` | | Exit override | `program.exitOverride()` + try/catch | | Choices | `new Option("--size <s>").choices(["s","m","l"])` | | Env fallback | `new Option("--port <n>").env("PORT")` |