📜package.json

JS ⟩ module ⟩ CommonJS ⟩ package.json

(in Node.js)

• ES modules can import ES or CommonJS module exports.

• CommonJS modules can only require CommonJS module exports.

"type": "module"      // ES module
"type": "commonjs"    // CommonJS module (⭐️ default)

                    ES export    CommonJS exports
-------------------------------------------------
ES import           ✅           ✅
CommonJS require    ❌           ✅ 
-------------------------------------------------
⭐️ looks like CommonJS "module.exports" is a better choice❓ 

🧨 雷區

in an ES module (.mjs / .js of "type":"module")：

• can only use import / export .

• can import CommonJS exports.

• cannot use require.

in an CommonJS module (.cjs / .js of "type":"commonjs")：

• cannot use require to load an ES module.

⭐️ 重點

• .cjs -> CommonJS module.

• .mjs -> ES module.

• .js

  • "module" -> ES module.

  • "commonjs" -> CommonJS module.

📗 參考

• Using ES modules with CommonJS modules in Node.js