{"id":35010,"date":"2025-11-24T20:40:51","date_gmt":"2025-11-24T17:40:51","guid":{"rendered":"https:\/\/fatihsoysal.com\/blog\/?p=35010"},"modified":"2025-11-24T20:40:51","modified_gmt":"2025-11-24T17:40:51","slug":"node-js-modulu-olusturma-rehberi-temellerden-ileri-seviyeye","status":"publish","type":"post","link":"https:\/\/fatihsoysal.com\/blog\/node-js-modulu-olusturma-rehberi-temellerden-ileri-seviyeye\/","title":{"rendered":"Node.js Mod\u00fcl\u00fc Olu\u015fturma Rehberi: Temellerden \u0130leri Seviyeye"},"content":{"rendered":"

<\/p>\n

Node.js Mod\u00fcl\u00fc Olu\u015fturma Rehberi: Temellerden \u0130leri Seviyeye<\/h2>\n

Node.js, sunucu taraf\u0131 uygulamalar geli\u015ftirmek i\u00e7in tasarlanm\u0131\u015f, olay tabanl\u0131, asenkron bir JavaScript \u00e7al\u0131\u015fma zaman\u0131 ortam\u0131d\u0131r. Node.js’in g\u00fcc\u00fcn\u00fcn \u00f6nemli bir k\u0131sm\u0131, kodun yeniden kullan\u0131labilirli\u011fini, bak\u0131m\u0131n\u0131 ve \u00f6l\u00e7eklenebilirli\u011fini art\u0131ran mod\u00fcl sisteminden gelir. Mod\u00fcller, kodunuzu mant\u0131ksal olarak izole edilmi\u015f, k\u00fc\u00e7\u00fck ve y\u00f6netilebilir par\u00e7alara ay\u0131rman\u0131za olanak tan\u0131r. Bu sayede, b\u00fcy\u00fck ve karma\u015f\u0131k uygulamalar\u0131 daha kolay geli\u015ftirebilir, i\u015fbirli\u011fi yapabilir ve hata ay\u0131klayabilirsiniz. Bu kapsaml\u0131 rehberde, Node.js mod\u00fcllerinin temel prensiplerinden ba\u015flayarak, CommonJS ve ES Mod\u00fclleri aras\u0131ndaki farklar\u0131, mod\u00fcl olu\u015fturma ve kullanma y\u00f6ntemlerini, ileri d\u00fczey konular\u0131 ve en iyi uygulamalar\u0131 derinlemesine inceleyece\u011fiz. Amac\u0131m\u0131z, Node.js ekosisteminde kendi mod\u00fcllerinizi etkin bir \u015fekilde olu\u015fturma ve y\u00f6netme konusunda size sa\u011flam bir temel sa\u011flamakt\u0131r.<\/p>\n

Node.js Mod\u00fcllerine Genel Bak\u0131\u015f<\/h2>\n

Mod\u00fcller, Node.js uygulamalar\u0131n\u0131n yap\u0131 ta\u015flar\u0131d\u0131r. Her bir JavaScript dosyas\u0131, varsay\u0131lan olarak kendi kapsam\u0131na (scope) sahiptir ve bu dosya i\u00e7erisinde tan\u0131mlanan de\u011fi\u015fkenler, fonksiyonlar veya s\u0131n\u0131flar, d\u0131\u015far\u0131dan do\u011frudan eri\u015filemez. Bir dosyadan di\u011ferine kod payla\u015f\u0131m\u0131 yapmak i\u00e7in, belirli \u00f6\u011felerin d\u0131\u015fa aktar\u0131lmas\u0131 (export) ve ba\u015fka bir dosyada i\u00e7e aktar\u0131lmas\u0131 (import) gerekir. Bu mekanizma, global de\u011fi\u015fken karma\u015fas\u0131n\u0131 \u00f6nler ve kodun daha d\u00fczenli olmas\u0131n\u0131 sa\u011flar.<\/p>\n

Neden Mod\u00fcller Kullanmal\u0131y\u0131z?<\/h3>\n

Mod\u00fcler programlaman\u0131n bir\u00e7ok avantaj\u0131 vard\u0131r:<\/p>\n

* Yeniden Kullan\u0131labilirlik:<\/strong> Bir kez yaz\u0131lan bir mod\u00fcl, uygulaman\u0131n farkl\u0131 yerlerinde veya hatta farkl\u0131 projelerde tekrar kullan\u0131labilir. Bu, geli\u015ftirme s\u00fcresini k\u0131salt\u0131r ve kod tekrar\u0131n\u0131 azalt\u0131r.
\n* Bak\u0131m Kolayl\u0131\u011f\u0131:<\/strong> Kod par\u00e7alar\u0131n\u0131 mod\u00fcllere ay\u0131rmak, hatalar\u0131 bulmay\u0131 ve d\u00fczeltmeyi kolayla\u015ft\u0131r\u0131r. Bir mod\u00fcldeki de\u011fi\u015fiklikler, uygulaman\u0131n di\u011fer b\u00f6l\u00fcmlerini do\u011frudan etkilemez, bu da yan etki riskini azalt\u0131r.
\n* Okunabilirlik:<\/strong> Mod\u00fcller, kodunuzu daha organize ve anla\u015f\u0131l\u0131r hale getirir. Her mod\u00fcl belirli bir g\u00f6revi yerine getirdi\u011fi i\u00e7in, kodun ne i\u015f yapt\u0131\u011f\u0131n\u0131 anlamak daha kolayd\u0131r.
\n* Ad Alan\u0131 \u00c7ak\u0131\u015fmalar\u0131n\u0131 \u00d6nleme:<\/strong> Her mod\u00fcl\u00fcn kendi \u00f6zel kapsam\u0131 oldu\u011fundan, farkl\u0131 mod\u00fcllerde ayn\u0131 isimde de\u011fi\u015fkenler veya fonksiyonlar tan\u0131mlamak ad \u00e7ak\u0131\u015fmalar\u0131na yol a\u00e7maz.
\n* Ba\u011f\u0131ml\u0131l\u0131k Y\u00f6netimi:<\/strong> Mod\u00fcller, bir dosyan\u0131n hangi di\u011fer dosyalara veya k\u00fct\u00fcphanelere ba\u011f\u0131ml\u0131 oldu\u011funu a\u00e7\u0131k\u00e7a belirtir. Bu, ba\u011f\u0131ml\u0131l\u0131k grafi\u011fini anlamay\u0131 ve y\u00f6netmeyi kolayla\u015ft\u0131r\u0131r.
\n* \u00d6l\u00e7eklenebilirlik:<\/strong> B\u00fcy\u00fck uygulamalar, k\u00fc\u00e7\u00fck, ba\u011f\u0131ms\u0131z mod\u00fcllerden olu\u015fturuldu\u011funda daha kolay \u00f6l\u00e7eklenebilir ve y\u00f6netilebilir hale gelir.<\/p>\n

Mod\u00fcl Tipleri: CommonJS ve ES Mod\u00fclleri<\/h3>\n

Node.js, tarihsel olarak CommonJS mod\u00fcl sistemini kullanm\u0131\u015ft\u0131r. Ancak, JavaScript dilinin kendisi, ECMAScript 2015 (ES6) ile birlikte kendi standart mod\u00fcl sistemini (ES Mod\u00fclleri veya ESM) tan\u0131tt\u0131. Node.js, bu iki sistemi de desteklemektedir, ancak aralar\u0131nda \u00f6nemli farklar ve kullan\u0131m senaryolar\u0131 bulunmaktad\u0131r.<\/p>\n

* CommonJS (CJS):<\/strong> Node.js’in geleneksel mod\u00fcl sistemidir. require()<\/code> fonksiyonu ile mod\u00fcller i\u00e7e aktar\u0131l\u0131r ve module.exports<\/code> veya exports<\/code> nesnesi ile d\u0131\u015fa aktar\u0131l\u0131r. Senkron bir y\u00fckleme mekanizmas\u0131na sahiptir, yani bir mod\u00fcl tamamen y\u00fcklenmeden \u00f6nce kodun geri kalan\u0131 y\u00fcr\u00fct\u00fclmez. \u00c7o\u011fu eski Node.js projesi ve npm paketi CommonJS kullan\u0131r.
\n* ES Mod\u00fclleri (ESM):<\/strong> JavaScript dilinin standart mod\u00fcl sistemidir. import<\/code> ve export<\/code> anahtar kelimeleri ile mod\u00fcller i\u00e7e ve d\u0131\u015fa aktar\u0131l\u0131r. Asenkron y\u00fcklemeyi destekler ve taray\u0131c\u0131 ortam\u0131nda da kullan\u0131lan standartt\u0131r. Node.js’te ES Mod\u00fcllerini kullanmak i\u00e7in genellikle package.json<\/code> dosyas\u0131nda \"type\": \"module\"<\/code> belirtilmesi veya .mjs<\/code> uzant\u0131s\u0131 kullan\u0131lmas\u0131 gerekir.<\/p>\n

Bu iki mod\u00fcl sistemi aras\u0131ndaki ge\u00e7i\u015f ve birlikte \u00e7al\u0131\u015fma, Node.js geli\u015ftiricileri i\u00e7in \u00f6nemli bir konudur.<\/p>\n

Basit Bir CommonJS Mod\u00fcl\u00fc Olu\u015fturma<\/h2>\n

CommonJS, Node.js’in varsay\u0131lan mod\u00fcl sistemidir ve hala bir\u00e7ok projede yayg\u0131n olarak kullan\u0131lmaktad\u0131r. Temel bir CommonJS mod\u00fcl\u00fc olu\u015fturmak olduk\u00e7a basittir.<\/p>\n

\u00d6ncelikle, bir fonksiyon veya de\u011feri d\u0131\u015fa aktarmak istedi\u011finiz bir JavaScript dosyas\u0131 olu\u015fturun. \u00d6rne\u011fin, matematik.js<\/code> ad\u0131nda bir dosya olu\u015ftural\u0131m:<\/p>\n

\/\/ matematik.js\nfunction topla(a, b) {\n  return a + b;\n}\n\nfunction cikar(a, b) {\n  return a - b;\n}\n\n\/\/ Bu fonksiyonlar\u0131 d\u0131\u015fa aktarman\u0131n yollar\u0131<\/code><\/pre>\n
module.exports<\/code> ve exports<\/code> Kullan\u0131m\u0131<\/h3>\n
CommonJS’te d\u0131\u015fa aktarma i\u00e7in iki ana y\u00f6ntem vard\u0131r: module.exports<\/code> ve exports<\/code>.<\/p>\n
*   module.exports<\/code>:<\/strong> Bu, bir mod\u00fcl\u00fcn d\u0131\u015fa aktard\u0131\u011f\u0131 ger\u00e7ek nesnedir. Bir mod\u00fclden tek bir \u015fey (bir fonksiyon, bir obje, bir s\u0131n\u0131f vb.) d\u0131\u015fa aktarmak istedi\u011finizde idealdir. module.exports<\/code>‘a bir de\u011fer atad\u0131\u011f\u0131n\u0131zda, bu de\u011fer mod\u00fcl\u00fcn kendisi olur.<\/p>\n
\/\/ matematik.js (module.exports ile tek bir nesne d\u0131\u015fa aktarma)\n    function topla(a, b) {\n      return a + b;\n    }\n\n    function cikar(a, b) {\n      return a - b;\n    }\n\n    const islemler = {\n      topla: topla,\n      cikar: cikar\n    };\n\n    module.exports = islemler;<\/code><\/pre>\n
    Bu durumda, matematik.js<\/code> mod\u00fcl\u00fcn\u00fc i\u00e7e aktard\u0131\u011f\u0131n\u0131zda, islemler<\/code> nesnesini al\u0131rs\u0131n\u0131z.<\/p>\n
*   exports<\/code>:<\/strong> Bu, module.exports<\/code>‘a bir referanst\u0131r (exports = module.exports = {}<\/code> ba\u015flang\u0131\u00e7ta). Genellikle, birden fazla \u00f6\u011feyi d\u0131\u015fa aktarmak i\u00e7in kullan\u0131l\u0131r. exports<\/code> nesnesine \u00f6zellikler ekleyerek (\u00f6rne\u011fin, exports.topla = topla;<\/code>) d\u0131\u015fa aktarma yapars\u0131n\u0131z.<\/p>\n
\/\/ matematik.js (exports ile birden fazla \u00f6\u011fe d\u0131\u015fa aktarma)\n    function topla(a, b) {\n      return a + b;\n    }\n\n    function cikar(a, b) {\n      return a - b;\n    }\n\n    exports.topla = topla;\n    exports.cikar = cikar;\n    \/\/ exports.carp = (a, b) => a * b; \/\/ Do\u011frudan da eklenebilir<\/code><\/pre>\n
    \u00d6nemli Not:<\/strong> exports<\/code> do\u011frudan module.exports<\/code>‘a bir referans oldu\u011fu i\u00e7in, exports = yeniDeger;<\/code> gibi bir atama yapmak, exports<\/code> referans\u0131n\u0131 keser ve beklenen d\u0131\u015fa aktarmay\u0131 yapmaz. Her zaman module.exports = yeniDeger;<\/code> kullan\u0131n veya exports.ozellik = deger;<\/code> \u015feklinde \u00f6zellik ekleyin.<\/p>\n
    Genellikle, tek bir de\u011fer d\u0131\u015fa aktar\u0131lacaksa module.exports = ...<\/code> kullan\u0131l\u0131rken, birden fazla adland\u0131r\u0131lm\u0131\u015f de\u011fer d\u0131\u015fa aktar\u0131lacaksa exports.ad = ...<\/code> kullan\u0131l\u0131r.<\/p>\n
Mod\u00fcl\u00fc Ba\u015fka Bir Dosyada Kullanma<\/h3>\n
Bir CommonJS mod\u00fcl\u00fcn\u00fc ba\u015fka bir dosyada kullanmak i\u00e7in require()<\/code> fonksiyonunu kullan\u0131r\u0131z.<\/p>\n
\/\/ app.js\nconst matematik = require('.\/matematik.js'); \/\/ .js uzant\u0131s\u0131 iste\u011fe ba\u011fl\u0131d\u0131r\n\nconsole.log('2 + 3 =', matematik.topla(2, 3)); \/\/ \u00c7\u0131kt\u0131: 2 + 3 = 5\nconsole.log('5 - 2 =', matematik.cikar(5, 2)); \/\/ \u00c7\u0131kt\u0131: 5 - 2 = 3\n\n\/\/ E\u011fer matematik.js dosyas\u0131nda sadece topla fonksiyonunu d\u0131\u015fa aktarm\u0131\u015f olsayd\u0131k:\n\/\/ module.exports = topla;\n\/\/ O zaman i\u00e7e aktarma \u015f\u00f6yle olurdu:\n\/\/ const topla = require('.\/matematik.js');\n\/\/ console.log(topla(2,3));<\/code><\/pre>\n
require()<\/code> fonksiyonuna verdi\u011fimiz yol, i\u00e7e aktar\u0131lacak mod\u00fcl\u00fcn bulundu\u011fu dizine g\u00f6receli olmal\u0131d\u0131r (\u00f6rn. .\/<\/code> veya ..\/<\/code>). E\u011fer bir npm paketi i\u00e7e aktar\u0131yorsak (\u00f6rn. express<\/code>), sadece paket ad\u0131n\u0131 belirtiriz ve Node.js bunu node_modules<\/code> dizininde arar.<\/p>\n
ES Mod\u00fcllerine Ge\u00e7i\u015f<\/h2>\n
ES Mod\u00fclleri, modern JavaScript geli\u015ftirmenin gelece\u011fidir ve hem taray\u0131c\u0131lar hem de Node.js taraf\u0131ndan desteklenmektedir. CommonJS’e g\u00f6re daha statik analiz dostu, asenkron ve daha esnek bir yap\u0131 sunarlar.<\/p>\n
package.json<\/code>‘da \"type\": \"module\"<\/code> Ayar\u0131<\/h3>\n
Node.js’te bir dizindeki t\u00fcm .js<\/code> dosyalar\u0131n\u0131 varsay\u0131lan olarak ES Mod\u00fcl\u00fc olarak ele almak i\u00e7in, projenizin package.json<\/code> dosyas\u0131na \"type\": \"module\"<\/code> eklemeniz gerekir:<\/p>\n
\/\/ package.json\n{\n  \"name\": \"es-module-ornek\",\n  \"version\": \"1.0.0\",\n  \"description\": \"ES Mod\u00fclleri ile Node.js uygulamas\u0131\",\n  \"main\": \"app.js\",\n  \"type\": \"module\", \/\/ Bu sat\u0131r \u00f6nemlidir\n  \"scripts\": {\n    \"start\": \"node app.js\"\n  },\n  \"keywords\": [],\n  \"author\": \"\",\n  \"license\": \"ISC\"\n}<\/code><\/pre>\n
E\u011fer \"type\": \"module\"<\/code> ayar\u0131n\u0131 yapmazsan\u0131z, .js<\/code> uzant\u0131l\u0131 dosyalar CommonJS olarak kabul edilir. Alternatif olarak, tek tek dosyalar\u0131 ES Mod\u00fcl\u00fc olarak i\u015faretlemek i\u00e7in .mjs<\/code> uzant\u0131s\u0131n\u0131 kullanabilirsiniz (\u00f6rn. matematik.mjs<\/code>). CommonJS mod\u00fclleri i\u00e7in ise .cjs<\/code> uzant\u0131s\u0131 kullan\u0131l\u0131r.<\/p>\n
import<\/code> ve export<\/code> S\u00f6zdizimi<\/h3>\n
ES Mod\u00fcllerinde d\u0131\u015fa ve i\u00e7e aktarma i\u00e7in export<\/code> ve import<\/code> anahtar kelimeleri kullan\u0131l\u0131r.<\/p>\n
*   Adland\u0131r\u0131lm\u0131\u015f D\u0131\u015fa Aktarmalar (Named Exports):<\/strong> Birden fazla \u00f6\u011feyi d\u0131\u015fa aktarmak i\u00e7in kullan\u0131l\u0131r.<\/p>\n
\/\/ matematik.js (ES Mod\u00fcl\u00fc)\n    export function topla(a, b) {\n      return a + b;\n    }\n\n    export function cikar(a, b) {\n      return a - b;\n    }\n\n    export const PI = 3.14159;<\/code><\/pre>\n
    \u0130\u00e7e aktarma:<\/p>\n
\/\/ app.js (ES Mod\u00fcl\u00fc)\n    import { topla, cikar, PI } from '.\/matematik.js';\n\n    console.log('2 + 3 =', topla(2, 3));\n    console.log('5 - 2 =', cikar(5, 2));\n    console.log('PI de\u011feri:', PI);\n\n    \/\/ Farkl\u0131 bir isimle i\u00e7e aktarma\n    \/\/ import { topla as add } from '.\/matematik.js';\n    \/\/ console.log(add(1,1));\n\n    \/\/ T\u00fcm adland\u0131r\u0131lm\u0131\u015f d\u0131\u015fa aktarmalar\u0131 bir obje olarak i\u00e7e aktarma\n    \/\/ import * as matematikIslemleri from '.\/matematik.js';\n    \/\/ console.log(matematikIslemleri.topla(10, 20));<\/code><\/pre>\n
*   Varsay\u0131lan D\u0131\u015fa Aktarmalar (Default Exports):<\/strong> Bir mod\u00fclden tek bir birincil \u00f6\u011feyi d\u0131\u015fa aktarmak i\u00e7in kullan\u0131l\u0131r. Her mod\u00fclde yaln\u0131zca bir varsay\u0131lan d\u0131\u015fa aktarma olabilir.<\/p>\n
\/\/ kullanici.js (ES Mod\u00fcl\u00fc)\n    class Kullanici {\n      constructor(ad, soyad) {\n        this.ad = ad;\n        this.soyad = soyad;\n      }\n\n      tamAd() {\n        return ${this.ad} ${this.soyad}<\/code>;\n      }\n    }\n\n    export default Kullanici; \/\/ Sadece bir tane default export olabilir<\/code><\/pre>\n
    \u0130\u00e7e aktarma:<\/p>\n
\/\/ app.js (ES Mod\u00fcl\u00fc)\n    import Kullanici from '.\/kullanici.js'; \/\/ S\u00fcsl\u00fc parantez olmadan, herhangi bir isimle i\u00e7e aktar\u0131labilir\n\n    const user = new Kullanici('Ay\u015fe', 'Y\u0131lmaz');\n    console.log(user.tamAd()); \/\/ \u00c7\u0131kt\u0131: Ay\u015fe Y\u0131lmaz<\/code><\/pre>\n
    Varsay\u0131lan ve adland\u0131r\u0131lm\u0131\u015f d\u0131\u015fa aktarmalar\u0131 ayn\u0131 mod\u00fclde birle\u015ftirmek de m\u00fcmk\u00fcnd\u00fcr:<\/p>\n
\/\/ servis.js\n    export const API_URL = 'https:\/\/api.example.com';\n\n    class Servis {\n      constructor() { \/ ... <\/em>\/ }\n      fetchData() { \/ ... <\/em>\/ }\n    }\n\n    export default Servis;<\/code><\/pre>\n
\/\/ app.js\n    import Servis, { API_URL } from '.\/servis.js';\n\n    console.log(API_URL);\n    const myService = new Servis();<\/code><\/pre>\n
CommonJS ve ES Mod\u00fcllerini Birlikte Kullanma<\/h3>\n
Node.js, farkl\u0131 mod\u00fcl sistemleri aras\u0131nda bir miktar birlikte \u00e7al\u0131\u015fabilirlik sunar.<\/p>\n
*   ES Mod\u00fcl\u00fcnden CommonJS Mod\u00fcl\u00fcn\u00fc \u0130\u00e7e Aktarma:<\/strong> Bir ES Mod\u00fcl\u00fc, import<\/code> s\u00f6zdizimi ile bir CommonJS mod\u00fcl\u00fcn\u00fc i\u00e7e aktarabilir. CommonJS mod\u00fcl\u00fcn\u00fcn module.exports<\/code> de\u011feri, ES Mod\u00fcl\u00fcn\u00fcn varsay\u0131lan d\u0131\u015fa aktarmas\u0131 olarak ele al\u0131n\u0131r. Adland\u0131r\u0131lm\u0131\u015f d\u0131\u015fa aktarmalar i\u00e7in ise CommonJS mod\u00fcl\u00fcn\u00fcn d\u0131\u015fa aktard\u0131\u011f\u0131 nesnenin \u00f6zellikleri kullan\u0131l\u0131r.<\/p>\n
\/\/ commonjs-modul.cjs (veya .js ve package.json'da \"type\": \"commonjs\" varsay\u0131m\u0131yla)\n    module.exports = {\n      selamla: (isim) => Merhaba, ${isim}!<\/code>,\n      versiyon: '1.0.0'\n    };<\/code><\/pre>\n
\/\/ es-modul.mjs (veya .js ve package.json'da \"type\": \"module\" varsay\u0131m\u0131yla)\n    import commonModule from '.\/commonjs-modul.cjs'; \/\/ Varsay\u0131lan i\u00e7e aktarma\n    \/\/ Veya adland\u0131r\u0131lm\u0131\u015f olarak:\n    \/\/ import { selamla, versiyon } from '.\/commonjs-modul.cjs';\n\n    console.log(commonModule.selamla('D\u00fcnya'));\n    console.log('Versiyon:', commonModule.versiyon);<\/code><\/pre>\n
*   CommonJS Mod\u00fcl\u00fcnden ES Mod\u00fcl\u00fcn\u00fc \u0130\u00e7e Aktarma:<\/strong> Bu durum biraz daha karma\u015f\u0131kt\u0131r \u00e7\u00fcnk\u00fc CommonJS senkron, ES Mod\u00fclleri ise asenkrondur. CommonJS mod\u00fclleri, do\u011frudan import<\/code> anahtar kelimesini kullanamaz. Bunun yerine, dinamik import()<\/code> fonksiyonunu kullanmalar\u0131 gerekir. Bu, bir Promise d\u00f6nd\u00fcr\u00fcr ve asenkron bir ba\u011flamda ele al\u0131nmal\u0131d\u0131r.<\/p>\n
\/\/ es-modul.mjs\n    export const mesaj = 'Bu bir ES Mod\u00fcl\u00fc mesaj\u0131d\u0131r.';\n    export default 'Varsay\u0131lan ES Mod\u00fcl\u00fc';<\/code><\/pre>\n
\/\/ commonjs-app.js\n    async function main() {\n      const esModule = await import('.\/es-modul.mjs');\n      console.log(esModule.default); \/\/ \u00c7\u0131kt\u0131: Varsay\u0131lan ES Mod\u00fcl\u00fc\n      console.log(esModule.mesaj);   \/\/ \u00c7\u0131kt\u0131: Bu bir ES Mod\u00fcl\u00fc mesaj\u0131d\u0131r.\n    }\n\n    main();<\/code><\/pre>\n
    Bu durum, top-level await<\/code> \u00f6zelli\u011finin Node.js 14 ve sonras\u0131 s\u00fcr\u00fcmlerinde ES mod\u00fcllerinde do\u011frudan kullan\u0131labilmesiyle daha da kolayla\u015fm\u0131\u015ft\u0131r, ancak CommonJS mod\u00fcllerinde hala async<\/code> fonksiyonlar i\u00e7inde await import()<\/code> kullanmak gereklidir.<\/p>\n
Mod\u00fclleri Daha Kapsaml\u0131 Hale Getirme<\/h2>\n
Mod\u00fcller sadece basit fonksiyonlar\u0131 d\u0131\u015fa aktarmakla kalmaz, ayn\u0131 zamanda daha karma\u015f\u0131k veri yap\u0131lar\u0131n\u0131 ve davran\u0131\u015flar\u0131 da i\u00e7erebilir.<\/p>\n
Birden Fazla Fonksiyon ve De\u011fi\u015fken D\u0131\u015fa Aktarma<\/h3>\n
Yukar\u0131daki \u00f6rneklerde g\u00f6rd\u00fc\u011f\u00fcm\u00fcz gibi, hem CommonJS hem de ES Mod\u00fcllerinde birden fazla fonksiyon, de\u011fi\u015fken veya sabit d\u0131\u015fa aktar\u0131labilir.<\/p>\n
CommonJS:<\/strong><\/p>\n
\/\/ util.js\nexports.sayHello = (name) => Hello, ${name}!<\/code>;\nexports.addNumbers = (a, b) => a + b;\nexports.APP_VERSION = '1.0.0';<\/code><\/pre>\n
ES Mod\u00fclleri:<\/strong><\/p>\n
\/\/ util.mjs\nexport const sayHello = (name) => Hello, ${name}!<\/code>;\nexport const addNumbers = (a, b) => a + b;\nexport const APP_VERSION = '1.0.0';<\/code><\/pre>\n
Varsay\u0131lan D\u0131\u015fa Aktarma (Default Exports)<\/h3>\n
ES Mod\u00fcllerine \u00f6zg\u00fc olan varsay\u0131lan d\u0131\u015fa aktarma, bir mod\u00fcl\u00fcn ana i\u015flevini veya ana nesnesini belirtmek i\u00e7in kullan\u0131l\u0131r. Mod\u00fcl\u00fc i\u00e7e aktar\u0131rken s\u00fcsl\u00fc parantez kullanmadan do\u011frudan bir isimle eri\u015filebilir.<\/p>\n
\/\/ database.mjs\nclass Database {\n  constructor(connectionString) {\n    this.connectionString = connectionString;\n  }\n\n  connect() {\n    console.log(Connecting to ${this.connectionString}...<\/code>);\n    \/\/ Ba\u011flant\u0131 mant\u0131\u011f\u0131\n  }\n\n  query(sql) {\n    console.log(Executing query: ${sql}<\/code>);\n    \/\/ Sorgu mant\u0131\u011f\u0131\n    return [];\n  }\n}\n\nexport default Database;<\/code><\/pre>\n
\/\/ app.mjs\nimport DB from '.\/database.mjs'; \/\/ \u0130stedi\u011fimiz bir isimle i\u00e7e aktarabiliriz\n\nconst myDb = new DB('mongodb:\/\/localhost:27017\/mydb');\nmyDb.connect();\nmyDb.query('SELECT * FROM users');<\/code><\/pre>\n
S\u0131n\u0131flar\u0131 ve Nesneleri D\u0131\u015fa Aktarma<\/h3>\n
Mod\u00fcller, JavaScript s\u0131n\u0131flar\u0131n\u0131 veya do\u011frudan nesne de\u011fi\u015fmezlerini (object literals) d\u0131\u015fa aktarmak i\u00e7in de kullan\u0131labilir. Bu, nesne tabanl\u0131 programlama prensiplerini uygularken olduk\u00e7a faydal\u0131d\u0131r.<\/p>\n
CommonJS ile S\u0131n\u0131f D\u0131\u015fa Aktarma:<\/strong><\/p>\n
\/\/ user.js\nclass User {\n  constructor(id, name) {\n    this.id = id;\n    this.name = name;\n  }\n\n  greet() {\n    return Hello, my name is ${this.name}.<\/code>;\n  }\n}\n\nmodule.exports = User;<\/code><\/pre>\n
\/\/ app.js\nconst User = require('.\/user.js');\nconst user1 = new User(1, 'Alice');\nconsole.log(user1.greet());<\/code><\/pre>\n
ES Mod\u00fclleri ile S\u0131n\u0131f D\u0131\u015fa Aktarma:<\/strong><\/p>\n
\/\/ product.mjs\nexport class Product {\n  constructor(id, name, price) {\n    this.id = id;\n    this.name = name; name;\n    this.price = price;\n  }\n\n  getPriceWithTax(taxRate) {\n    return this.price * (1 + taxRate);\n  }\n}<\/code><\/pre>\n
\/\/ app.mjs\nimport { Product } from '.\/product.mjs';\nconst item = new Product(101, 'Laptop', 1200);\nconsole.log(Laptop price with 18% tax: $${item.getPriceWithTax(0.18).toFixed(2)}<\/code>);<\/code><\/pre>\n
Nesne D\u0131\u015fa Aktarma (Hem CommonJS hem de ES Mod\u00fclleri):<\/strong><\/p>\n
\/\/ config.js (CommonJS)\nmodule.exports = {\n  dbHost: 'localhost',\n  dbPort: 5432,\n  apiTimeout: 5000\n};<\/code><\/pre>\n
\/\/ config.mjs (ES Mod\u00fcl\u00fc)\nconst config = {\n  dbHost: 'localhost',\n  dbPort: 5432,\n  apiTimeout: 5000\n};\nexport default config;\n\/\/ veya\n\/\/ export const dbHost = 'localhost';\n\/\/ export const dbPort = 5432;<\/code><\/pre>\n
Bu esneklik, mod\u00fcllerinizi uygulaman\u0131z\u0131n ihtiya\u00e7lar\u0131na g\u00f6re \u015fekillendirmenizi sa\u011flar.<\/p>\n
Mod\u00fcl Yollar\u0131 ve \u00c7\u00f6z\u00fcmleme<\/h2>\n
Node.js, require()<\/code> ve import<\/code> ifadelerindeki mod\u00fcl yollar\u0131n\u0131 nas\u0131l \u00e7\u00f6zd\u00fc\u011f\u00fcn\u00fc belirleyen karma\u015f\u0131k bir mekanizmaya sahiptir. Bu mekanizmay\u0131 anlamak, mod\u00fcllerinizi do\u011fru bir \u015fekilde i\u00e7e aktarman\u0131z i\u00e7in kritik \u00f6neme sahiptir.<\/p>\n
G\u00f6receli Yollar (Relative Paths)<\/h3>\n
.\/<\/code>, ..\/<\/code> veya \/<\/code> ile ba\u015flayan yollar g\u00f6receli yollard\u0131r. Bu yollar, i\u00e7e aktarma i\u015flemini yapan dosyan\u0131n konumuna g\u00f6re mod\u00fcl\u00fcn yerini belirtir.<\/p>\n
*   .\/modul.js<\/code>: Ayn\u0131 dizindeki modul.js<\/code> dosyas\u0131n\u0131 arar.
\n*   ..\/lib\/util.js<\/code>: Bir \u00fcst dizindeki lib<\/code> klas\u00f6r\u00fcndeki util.js<\/code> dosyas\u0131n\u0131 arar.
\n*   \/src\/data.js<\/code>: Projenin k\u00f6k dizininden (veya ge\u00e7erli \u00e7al\u0131\u015fma dizininden) ba\u015flayan mutlak bir yol gibi yorumlan\u0131r, ancak genellikle .<\/code> veya ..<\/code> ile ba\u015flayan g\u00f6receli yollar daha g\u00fcvenlidir.<\/p>\n
\u00d6rnek:<\/strong><\/p>\n
\/\/ proje-k\u00f6k\/\n\/\/ \u251c\u2500\u2500 src\/\n\/\/ \u2502   \u251c\u2500\u2500 components\/\n\/\/ \u2502   \u2502   \u2514\u2500\u2500 Button.js\n\/\/ \u2502   \u2514\u2500\u2500 utils\/\n\/\/ \u2502       \u2514\u2500\u2500 helper.js\n\/\/ \u2514\u2500\u2500 app.js<\/code><\/pre>\n
*   app.js<\/code> i\u00e7inden Button.js<\/code>‘i i\u00e7e aktarmak i\u00e7in: require('.\/src\/components\/Button.js')<\/code>
\n*   Button.js<\/code> i\u00e7inden helper.js<\/code>‘i i\u00e7e aktarmak i\u00e7in: require('..\/utils\/helper.js')<\/code><\/p>\n
Mutlak Yollar (Absolute Paths)<\/h3>\n
Mutlak yollar, dosya sisteminin k\u00f6k\u00fcnden ba\u015flar (\u00f6rn. \/home\/user\/project\/src\/module.js<\/code> veya C:\\Users\\user\\project\\src\\module.js<\/code>). Genellikle, __dirname<\/code> veya path<\/code> mod\u00fcl\u00fc ile olu\u015fturulurlar.<\/p>\n
\/\/ app.js\nconst path = require('path');\nconst myModule = require(path.join(__dirname, 'src', 'myModule.js'));<\/code><\/pre>\n
Bu y\u00f6ntem, dosyan\u0131n nerede \u00e7al\u0131\u015ft\u0131r\u0131ld\u0131\u011f\u0131na bak\u0131lmaks\u0131z\u0131n mod\u00fcl\u00fc do\u011fru bir \u015fekilde bulmay\u0131 sa\u011flar.<\/p>\n
node_modules<\/code> ve Dizine Dayal\u0131 \u00c7\u00f6z\u00fcmleme<\/h3>\n
E\u011fer require()<\/code> veya import<\/code> ifadesinde bir yol yerine sadece bir mod\u00fcl ad\u0131 (\u00f6rn. express<\/code>, lodash<\/code>) belirtilirse, Node.js bu mod\u00fcl\u00fc node_modules<\/code> dizininde arar. Arama s\u00fcreci \u015f\u00f6yledir:<\/p>\n
1.  Node.js, ge\u00e7erli dosyan\u0131n bulundu\u011fu dizinden ba\u015flayarak node_modules<\/code> dizinini arar.
\n2.  Bulamazsa, bir \u00fcst dizine \u00e7\u0131kar ve orada node_modules<\/code>‘u arar.
\n3.  Bu i\u015flem, dosya sisteminin k\u00f6k dizinine ula\u015fana kadar devam eder.<\/p>\n
Mod\u00fcl\u00fcn i\u00e7inde bir package.json<\/code> dosyas\u0131 varsa, Node.js bu dosyadaki \"main\"<\/code> (CommonJS i\u00e7in) veya \"exports\"<\/code> (ES Mod\u00fclleri i\u00e7in) alanlar\u0131n\u0131 kontrol ederek hangi dosyan\u0131n d\u0131\u015fa aktar\u0131lmas\u0131 gerekti\u011fini belirler. E\u011fer package.json<\/code> yoksa veya \"main\"<\/code> alan\u0131 belirtilmemi\u015fse, varsay\u0131lan olarak index.js<\/code> dosyas\u0131n\u0131 arar.<\/p>\n
\u00d6rnek:<\/strong><\/p>\n
\/\/ app.js\nconst express = require('express'); \/\/ node_modules'tan express paketini bulur\nconst _ = require('lodash');       \/\/ node_modules'tan lodash paketini bulur<\/code><\/pre>\n
NODE_PATH<\/code> ve Ortam De\u011fi\u015fkenleri<\/h3>\n
NODE_PATH<\/code> ortam de\u011fi\u015fkeni, Node.js’in mod\u00fclleri arayaca\u011f\u0131 ek dizinleri belirtmek i\u00e7in kullan\u0131labilir. Bu, global olarak y\u00fckl\u00fc mod\u00fcllere veya belirli bir projeye \u00f6zg\u00fc olmayan mod\u00fcllere eri\u015fmek i\u00e7in faydal\u0131 olabilir. Ancak, genellikle NODE_PATH<\/code> kullan\u0131m\u0131 \u00f6nerilmez \u00e7\u00fcnk\u00fc bu, mod\u00fcl \u00e7\u00f6z\u00fcmlemesini daha az tahmin edilebilir hale getirir ve ba\u011f\u0131ml\u0131l\u0131k y\u00f6netimini zorla\u015ft\u0131rabilir. Ba\u011f\u0131ml\u0131l\u0131klar\u0131 genellikle package.json<\/code> \u00fczerinden y\u00f6netmek ve node_modules<\/code> kullanmak en iyi uygulamad\u0131r.<\/p>\n
Asenkron Mod\u00fcller ve Geli\u015fmi\u015f Konular<\/h2>\n
Node.js, asenkron i\u015flemleri yo\u011fun bir \u015fekilde kullan\u0131r ve mod\u00fcl sistemi de bu paradigmay\u0131 destekler.<\/p>\n
Top-Level await<\/code> (\u00dcst D\u00fczey await<\/code>)<\/h3>\n
Node.js 14 ile birlikte, ES Mod\u00fcllerinde art\u0131k async<\/code> fonksiyonu i\u00e7ine almadan do\u011frudan await<\/code> anahtar kelimesini kullanmak m\u00fcmk\u00fcnd\u00fcr. Bu, mod\u00fcl\u00fcn ba\u015flang\u0131c\u0131nda asenkron kaynaklar\u0131 (veritaban\u0131 ba\u011flant\u0131s\u0131, API \u00e7a\u011fr\u0131s\u0131 vb.) y\u00fcklemeyi veya yap\u0131land\u0131rmay\u0131 kolayla\u015ft\u0131r\u0131r.<\/p>\n
\/\/ config.mjs\nimport { fetchData } from '.\/api.mjs';\n\nconsole.log('Mod\u00fcl y\u00fckleniyor...');\nconst initialConfig = await fetchData('\/settings'); \/\/ Mod\u00fcl seviyesinde await\n\nexport const appConfig = {\n  ...initialConfig,\n  port: process.env.PORT || 3000\n};\n\nconsole.log('Mod\u00fcl y\u00fcklendi ve yap\u0131land\u0131r\u0131ld\u0131.');<\/code><\/pre>\n
Bu \u00f6zellik yaln\u0131zca ES Mod\u00fclleri i\u00e7in ge\u00e7erlidir. CommonJS mod\u00fcllerinde hala async<\/code> fonksiyonlar i\u00e7inde await<\/code> kullanmak gerekir.<\/p>\n
Dinamik \u0130\u00e7e Aktarma (import()<\/code>)<\/h3>\n
import()<\/code> fonksiyonu, bir mod\u00fcl\u00fc \u00e7al\u0131\u015fma zaman\u0131nda (runtime) ko\u015fullu olarak veya iste\u011fe ba\u011fl\u0131 olarak y\u00fcklemek i\u00e7in kullan\u0131l\u0131r. Bir Promise d\u00f6nd\u00fcr\u00fcr ve mod\u00fcl\u00fcn y\u00fcklenmesi tamamland\u0131\u011f\u0131nda \u00e7\u00f6z\u00fcl\u00fcr. Bu, uygulaman\u0131z\u0131n ba\u015flang\u0131\u00e7 y\u00fckleme s\u00fcresini optimize etmek veya sadece belirli ko\u015fullar alt\u0131nda ihtiya\u00e7 duyulan mod\u00fclleri y\u00fcklemek i\u00e7in faydal\u0131d\u0131r.<\/p>\n
\/\/ app.js (CommonJS veya ES Mod\u00fcl\u00fc olabilir)\nconst userRole = 'admin'; \/\/ Bu bir veritaban\u0131 sorgusundan gelebilir\n\nasync function loadAdminModule() {\n  if (userRole === 'admin') {\n    const adminModule = await import('.\/admin-panel.mjs'); \/\/ Dinamik i\u00e7e aktarma\n    adminModule.showAdminDashboard();\n  } else {\n    console.log('Y\u00f6netici eri\u015fimi yok.');\n  }\n}\n\nloadAdminModule();<\/code><\/pre>\n
Dinamik import()<\/code> hem CommonJS hem de ES Mod\u00fcllerinde kullan\u0131labilir.<\/p>\n
Mod\u00fcl \u00d6nbellekleme (Module Caching)<\/h3>\n
Node.js, bir mod\u00fcl\u00fc ilk kez require()<\/code> veya import<\/code> etti\u011finde, mod\u00fcl\u00fc bellekte \u00f6nbelle\u011fe al\u0131r. Sonraki i\u00e7e aktarma istekleri, ayn\u0131 mod\u00fcl\u00fcn \u00f6nbelle\u011fe al\u0131nm\u0131\u015f kopyas\u0131n\u0131 d\u00f6nd\u00fcr\u00fcr. Bu, mod\u00fcl kodunun her seferinde yeniden y\u00fcr\u00fct\u00fclmesini \u00f6nler ve performans\u0131 art\u0131r\u0131r.<\/p>\n
\/\/ sayac.js\nlet count = 0;\nconsole.log('Sayac mod\u00fcl\u00fc y\u00fcklendi.'); \/\/ Bu sadece bir kez yazd\u0131r\u0131l\u0131r\n\nexports.increment = () => {\n  count++;\n  return count;\n};\n\nexports.getCount = () => count;<\/code><\/pre>\n
\/\/ app.js\nconst sayac1 = require('.\/sayac.js');\nconst sayac2 = require('.\/sayac.js'); \/\/ \u00d6nbellekten gelir\n\nconsole.log(sayac1.increment()); \/\/ \u00c7\u0131kt\u0131: 1\nconsole.log(sayac2.increment()); \/\/ \u00c7\u0131kt\u0131: 2 (ayn\u0131 \u00f6rnek \u00fczerinde \u00e7al\u0131\u015f\u0131yorlar)\nconsole.log(sayac1.getCount());  \/\/ \u00c7\u0131kt\u0131: 2<\/code><\/pre>\n
Mod\u00fcl \u00f6nbelle\u011fini manuel olarak temizlemek m\u00fcmk\u00fcnd\u00fcr (delete require.cache[modulePath]<\/code>), ancak genellikle bu \u00f6nerilmez ve sadece \u00e7ok \u00f6zel durumlarda (\u00f6rn. test senaryolar\u0131) kullan\u0131l\u0131r.<\/p>\n
Mod\u00fcl Y\u00fckleyici Kancalar\u0131 (Module Loader Hooks)<\/h3>\n
Node.js’in mod\u00fcl y\u00fckleme s\u00fcrecini daha derinlemesine kontrol etmek isteyen ileri d\u00fczey kullan\u0131c\u0131lar i\u00e7in mod\u00fcl y\u00fckleyici kancalar\u0131 mevcuttur. Bu kancalar, mod\u00fcllerin nas\u0131l \u00e7\u00f6z\u00fcld\u00fc\u011f\u00fcn\u00fc, y\u00fcklendi\u011fini ve d\u00f6n\u00fc\u015ft\u00fcr\u00fcld\u00fc\u011f\u00fcn\u00fc \u00f6zelle\u015ftirmeye olanak tan\u0131r. Genellikle \u00f6zel durumlar, \u00f6rne\u011fin TypeScript veya ba\u015fka bir dilin do\u011frudan Node.js’te d\u00f6n\u00fc\u015ft\u00fcr\u00fclerek \u00e7al\u0131\u015ft\u0131r\u0131lmas\u0131 gibi senaryolar i\u00e7in kullan\u0131l\u0131r. Bu, loader<\/code> mekanizmas\u0131 arac\u0131l\u0131\u011f\u0131yla node --experimental-loader .\/my-loader.js<\/code> gibi komutlarla etkinle\u015ftirilebilir. Bu, \u00f6zellikle transpiler’lar veya \u00f6zel dosya t\u00fcrlerini i\u015flemek i\u00e7in g\u00fc\u00e7l\u00fc bir ara\u00e7t\u0131r ancak kullan\u0131m\u0131 karma\u015f\u0131kt\u0131r ve genellikle \u00f6zel k\u00fct\u00fcphaneler taraf\u0131ndan soyutlan\u0131r (\u00f6rn. ts-node<\/code>).<\/p>\n
Mod\u00fcl Testi ve Dok\u00fcmantasyonu<\/h2>\n
G\u00fcvenilir ve s\u00fcrd\u00fcr\u00fclebilir mod\u00fcller olu\u015fturmak i\u00e7in test ve dok\u00fcmantasyon vazge\u00e7ilmezdir.<\/p>\n
Unit Testleri Yazma<\/h3>\n
Her bir mod\u00fcl\u00fcn beklenen \u015fekilde \u00e7al\u0131\u015ft\u0131\u011f\u0131ndan emin olmak i\u00e7in unit testleri yaz\u0131lmal\u0131d\u0131r. Pop\u00fcler test \u00e7er\u00e7eveleri aras\u0131nda Jest, Mocha ve Chai bulunur.<\/p>\n
Jest ile \u00d6rnek Test:<\/strong><\/p>\n
\/\/ matematik.js\nexports.topla = (a, b) => a + b;\nexports.carp = (a, b) => a * b;<\/code><\/pre>\n
\/\/ matematik.test.js\nconst matematik = require('.\/matematik');\n\ntest('iki say\u0131y\u0131 do\u011fru bir \u015fekilde toplar', () => {\n  expect(matematik.topla(1, 2)).toBe(3);\n});\n\ntest('iki say\u0131y\u0131 do\u011fru bir \u015fekilde \u00e7arpar', () => {\n  expect(matematik.carp(2, 3)).toBe(6);\n});\n\ntest('s\u0131f\u0131r ile \u00e7arp\u0131m s\u0131f\u0131r olmal\u0131', () => {\n  expect(matematik.carp(5, 0)).toBe(0);\n});<\/code><\/pre>\n
Testler, mod\u00fcl\u00fcn her bir fonksiyonunun veya metodunun izole bir \u015fekilde do\u011fru \u00e7al\u0131\u015ft\u0131\u011f\u0131n\u0131 do\u011frular. Bu, kodda de\u011fi\u015fiklik yap\u0131ld\u0131\u011f\u0131nda regresyon hatalar\u0131n\u0131 \u00f6nlemeye yard\u0131mc\u0131 olur.<\/p>\n
Dok\u00fcmantasyon Olu\u015fturma<\/h3>\n
Mod\u00fcl\u00fcn\u00fcz\u00fcn nas\u0131l kullan\u0131laca\u011f\u0131n\u0131, hangi fonksiyonlar\u0131 sundu\u011funu, parametrelerini ve d\u00f6n\u00fc\u015f de\u011ferlerini a\u00e7\u0131klayan iyi bir dok\u00fcmantasyon, di\u011fer geli\u015ftiricilerin (ve gelecekteki sizin) mod\u00fcl\u00fc anlamas\u0131n\u0131 ve kullanmas\u0131n\u0131 kolayla\u015ft\u0131r\u0131r. JSDoc gibi ara\u00e7lar, kodunuzdaki yorumlardan otomatik olarak dok\u00fcmantasyon olu\u015fturabilir.<\/p>\n
JSDoc \u00d6rne\u011fi:<\/strong><\/p>\n
\/<\/em>\n * \u0130ki say\u0131y\u0131 toplar.\n * @param {number} a - \u0130lk say\u0131.\n * @param {number} b - \u0130kinci say\u0131.\n * @returns {number} \u0130ki say\u0131n\u0131n toplam\u0131.\n *\/\nfunction topla(a, b) {\n  return a + b;\n}\n\n\/<\/em>\n * Kullan\u0131c\u0131 nesnesi.\n * @typedef {object} User\n * @property {number} id - Kullan\u0131c\u0131n\u0131n ID'si.\n * @property {string} name - Kullan\u0131c\u0131n\u0131n ad\u0131.\n *\/\n\n\/<\/em>\n * Yeni bir kullan\u0131c\u0131 olu\u015fturur.\n * @param {number} id - Kullan\u0131c\u0131n\u0131n benzersiz ID'si.\n * @param {string} name - Kullan\u0131c\u0131n\u0131n ad\u0131.\n * @returns {User} Yeni olu\u015fturulan kullan\u0131c\u0131 nesnesi.\n *\/\nfunction createUser(id, name) {\n  return { id, name };\n}\n\nmodule.exports = { topla, createUser };<\/code><\/pre>\n
Bu yorumlar, JSDoc arac\u0131 taraf\u0131ndan i\u015flenerek HTML, Markdown veya ba\u015fka formatlarda okunabilir bir dok\u00fcmantasyon haline getirilebilir.<\/p>\n
En \u0130yi Uygulamalar ve \u0130pu\u00e7lar\u0131<\/h2>\n
Node.js mod\u00fclleri geli\u015ftirirken g\u00f6z \u00f6n\u00fcnde bulundurman\u0131z gereken baz\u0131 en iyi uygulamalar ve ipu\u00e7lar\u0131:<\/p>\n
Mod\u00fcl Sorumlulu\u011fu<\/h3>\n
Her mod\u00fcl\u00fcn tek bir sorumlulu\u011fu olmal\u0131d\u0131r (Single Responsibility Principle – SRP). Bir mod\u00fcl, belirli bir g\u00f6revi veya bir dizi ili\u015fkili g\u00f6revi yerine getirmelidir. \u00d6rne\u011fin, bir mod\u00fcl sadece veritaban\u0131 i\u015flemleriyle ilgilenmeli, ba\u015fka bir mod\u00fcl ise kullan\u0131c\u0131 kimlik do\u011frulamas\u0131n\u0131 y\u00f6netmelidir. Bu, mod\u00fcllerin daha k\u00fc\u00e7\u00fck, daha y\u00f6netilebilir ve daha az hata yapmaya e\u011filimli olmas\u0131n\u0131 sa\u011flar.<\/p>\n
Ba\u011f\u0131ml\u0131l\u0131k Y\u00f6netimi<\/h3>\n
Mod\u00fcllerinizin ba\u011f\u0131ml\u0131l\u0131klar\u0131n\u0131 a\u00e7\u0131k\u00e7a belirtin ve y\u00f6netin. package.json<\/code> dosyas\u0131ndaki dependencies<\/code> ve devDependencies<\/code> alanlar\u0131n\u0131 do\u011fru bir \u015fekilde kullan\u0131n. M\u00fcmk\u00fcn oldu\u011funca, mod\u00fcllerin i\u00e7 ba\u011f\u0131ml\u0131l\u0131klar\u0131n\u0131 azalt\u0131n veya bunlar\u0131 soyutlay\u0131n. Ba\u011f\u0131ml\u0131l\u0131k enjeksiyonu (Dependency Injection) gibi desenler, mod\u00fcller aras\u0131 s\u0131k\u0131 ba\u011f\u0131ml\u0131l\u0131klar\u0131 gev\u015fetmek i\u00e7in kullan\u0131labilir.<\/p>\n
Hata Y\u00f6netimi<\/h3>\n
Mod\u00fcllerinizin i\u00e7indeki hatalar\u0131 uygun \u015fekilde ele al\u0131n. Bir mod\u00fcl bir hata durumuna d\u00fc\u015ft\u00fc\u011f\u00fcnde, bu hatay\u0131 \u00e7a\u011f\u0131ran koda bildirmeli veya uygun bir \u015fekilde loglamal\u0131d\u0131r. Callback’lerde hata objesini ilk parametre olarak d\u00f6nd\u00fcrmek (Node.js gelene\u011fi), Promise’leri reddetmek veya try-catch bloklar\u0131 kullanmak yayg\u0131n yakla\u015f\u0131mlard\u0131r.<\/p>\n
Performans \u0130pu\u00e7lar\u0131<\/h3>\n
*   Gereksiz Y\u00fcklemelerden Ka\u00e7\u0131n\u0131n:<\/strong> Yaln\u0131zca ihtiyac\u0131n\u0131z olan mod\u00fclleri i\u00e7e aktar\u0131n. Mod\u00fcl\u00fcn tamam\u0131n\u0131 i\u00e7e aktarmak yerine, sadece belirli fonksiyonlar\u0131 veya s\u0131n\u0131flar\u0131 i\u00e7e aktarabilirsiniz (ES Mod\u00fcllerinde import { func } from '.\/module.mjs';<\/code> gibi).
\n*   Mod\u00fcl \u00d6nbelle\u011fini Anlay\u0131n:<\/strong> Node.js mod\u00fcl \u00f6nbelleklemesini otomatik olarak yapar. Bu, bir mod\u00fcl\u00fc birden fazla kez require<\/code> veya import<\/code> etmenin ek bir maliyeti olmad\u0131\u011f\u0131 anlam\u0131na gelir. Ancak, mod\u00fcl\u00fcn ilk y\u00fcklenmesinde yap\u0131lan pahal\u0131 i\u015flemlerin (\u00f6rn. b\u00fcy\u00fck dosyalar\u0131 okuma, karma\u015f\u0131k hesaplamalar) yaln\u0131zca bir kez ger\u00e7ekle\u015fti\u011finden emin olun.
\n*   Dinamik \u0130\u00e7e Aktarmay\u0131 Kullan\u0131n:<\/strong> Uygulaman\u0131z\u0131n ba\u015flang\u0131\u00e7 s\u00fcresini k\u0131saltmak i\u00e7in, kritik olmayan veya nadiren kullan\u0131lan mod\u00fclleri dinamik olarak i\u00e7e aktarmay\u0131 d\u00fc\u015f\u00fcnebilirsiniz.<\/p>\n
Sonu\u00e7<\/h2>\n
Node.js mod\u00fcl sistemi, modern ve \u00f6l\u00e7eklenebilir uygulamalar geli\u015ftirmenin temelini olu\u015fturur. CommonJS’in geleneksel g\u00fcc\u00fcnden, ES Mod\u00fcllerinin modern esnekli\u011fine kadar, Node.js geli\u015ftiricilerine geni\u015f bir ara\u00e7 yelpazesi sunulmaktad\u0131r. Bu rehberde ele ald\u0131\u011f\u0131m\u0131z konular \u2013 mod\u00fcl tipleri, d\u0131\u015fa ve i\u00e7e aktarma y\u00f6ntemleri, mod\u00fcl yollar\u0131, ileri d\u00fczey asenkron konular, test ve dok\u00fcmantasyon \u2013 kendi Node.js mod\u00fcllerinizi olu\u015fturman\u0131z ve bunlar\u0131 projelerinizde etkin bir \u015fekilde kullanman\u0131z i\u00e7in size kapsaml\u0131 bir bilgi birikimi sa\u011flam\u0131\u015ft\u0131r.<\/p>\n
Mod\u00fcler programlama prensiplerini benimseyerek, kodunuzu daha okunabilir, bak\u0131m\u0131 daha kolay, yeniden kullan\u0131labilir ve i\u015fbirli\u011fine daha a\u00e7\u0131k hale getirebilirsiniz. Unutmay\u0131n ki iyi tasarlanm\u0131\u015f bir mod\u00fcl, sadece bir kod par\u00e7as\u0131 de\u011fil, ayn\u0131 zamanda uygulaman\u0131z\u0131n genel sa\u011fl\u0131\u011f\u0131na ve s\u00fcrd\u00fcr\u00fclebilirli\u011fine katk\u0131da bulunan de\u011ferli bir varl\u0131kt\u0131r. Kendi mod\u00fcllerinizi yazarken bu prensipleri g\u00f6z \u00f6n\u00fcnde bulundurarak, daha sa\u011flam ve ba\u015far\u0131l\u0131 Node.js uygulamalar\u0131 geli\u015ftireceksiniz.<\/body><\/p>\n","protected":false},"excerpt":{"rendered":"Node.js Mod\u00fcl\u00fc Olu\u015fturma Rehberi: Temellerden \u0130leri Seviyeye\nNode.js, sunucu taraf\u0131 uygulamalar geli\u015ftirmek i\u00e7in tasarlanm\u0131\u015f, olay tabanl\u0131,","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"csco_page_header_type":"","csco_page_load_nextpost":"","csco_page_subscribe_form":"","csco_page_contact_form":"","footnotes":""},"categories":[136],"tags":[],"class_list":{"0":"post-35010","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-node-js","7":"cs-entry","8":"cs-video-wrap"},"yoast_head":"\nNode.js Mod\u00fcl\u00fc Olu\u015fturma Rehberi: Temellerden \u0130leri Seviyeye - 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