In the previous article How To Use Node Package Manager, we have learned what NPM is and how to use it to install, uninstall, update and search third-party NPM modules. This article will tell you how to create your own NPM modules.
1. NPM Module Directory Structure.
- If you install a third-party node module like Async locally, you can see a directory which name is async is created in your project node_modules folder. In that folder, there are a lot of JS files and particularly a package.json file.
- Each node module must contain a package.json file. It is a JSON format text file that describes the node module-related information such as author, homepage, license, main file, version, name, keywords, dependencies, repository, etc.
- Below is the async module package.json file content.
{ "_from": "async", "_id": "[email protected]", "_inBundle": false, "_integrity": "sha512-xAfGg1/NTLBBKlHFmnd7PlmUW9KhVQIUuSrYem9xzFUZy13ScvtyGGejaae9iAVRiRq9+Cx7DPFaAAhCpyxyPw==", "_location": "/async", "_phantomChildren": {}, "_requested": { "type": "tag", "registry": true, "raw": "async", "name": "async", "escapedName": "async", "rawSpec": "", "saveSpec": null, "fetchSpec": "latest" }, "_requiredBy": [ "#USER" ], "_resolved": "https://registry.npmjs.org/async/-/async-2.6.0.tgz", "_shasum": "61a29abb6fcc026fea77e56d1c6ec53a795951f4", "_spec": "async", "_where": "/Users/zhaosong/Documents/WorkSpace/dev2qa.com-example-code/JavaScriptExampleWorkspace/NodeJSWorkspace/AsyncExecute", "author": { "name": "Caolan McMahon" }, "bugs": { "url": "https://github.com/caolan/async/issues" }, "bundleDependencies": false, "dependencies": { "lodash": "^4.14.0" }, "deprecated": false, "description": "Higher-order functions and common patterns for asynchronous code", "devDependencies": { "babel-cli": "^6.24.0", "babel-core": "^6.24.0", "babel-plugin-add-module-exports": "^0.2.1", "babel-plugin-istanbul": "^2.0.1", "babel-plugin-transform-es2015-modules-commonjs": "^6.3.16", "babel-preset-es2015": "^6.3.13", "babel-preset-es2017": "^6.22.0", "babelify": "^7.2.0", "benchmark": "^2.1.1", "bluebird": "^3.4.6", "chai": "^3.1.0", "cheerio": "^0.22.0", "coveralls": "^2.11.2", "es6-promise": "^2.3.0", "eslint": "^2.13.1", "fs-extra": "^0.26.7", "gh-pages-deploy": "^0.4.2", "jsdoc": "^3.4.0", "karma": "^1.3.0", "karma-browserify": "^5.1.0", "karma-firefox-launcher": "^1.0.0", "karma-mocha": "^1.2.0", "karma-mocha-reporter": "^2.2.0", "mocha": "^3.1.2", "native-promise-only": "^0.8.0-a", "nyc": "^7.0.0", "recursive-readdir": "^1.3.0", "rimraf": "^2.5.0", "rollup": "^0.36.3", "rollup-plugin-node-resolve": "^2.0.0", "rollup-plugin-npm": "^2.0.0", "rsvp": "^3.0.18", "semver": "^4.3.6", "uglify-js": "~2.7.3", "vinyl-buffer": "^1.0.0", "vinyl-source-stream": "^1.1.0", "watchify": "^3.7.0", "yargs": "~3.9.1" }, "gh-pages-deploy": { "staticpath": "docs" }, "homepage": "https://caolan.github.io/async/", "keywords": [ "async", "callback", "module", "utility" ], "license": "MIT", "main": "dist/async.js", "name": "async", "nyc": { "exclude": [ "mocha_test" ] }, "repository": { "type": "git", "url": "git+https://github.com/caolan/async.git" }, "scripts": { "coverage": "nyc npm run mocha-node-test -- --grep @nycinvalid --invert", "coveralls": "npm run coverage && nyc report --reporter=text-lcov | coveralls", "jsdoc": "jsdoc -c ./support/jsdoc/jsdoc.json && node support/jsdoc/jsdoc-fix-html.js", "lint": "eslint lib/ mocha_test/ perf/memory.js perf/suites.js perf/benchmark.js support/build/ support/*.js karma.conf.js", "mocha-browser-test": "karma start", "mocha-node-test": "mocha mocha_test/ --compilers js:babel-core/register", "mocha-test": "npm run mocha-node-test && npm run mocha-browser-test", "test": "npm run lint && npm run mocha-node-test" }, "version": "2.6.0" }
2. Create Custom NPM Module.
- Run the below command in a terminal, it will create a module custom_module_1‘s package.json file in the current project node_modules folder.
$ mkdir node_modules $ cd node_modules $ mkdir custom_module_1 $ cd custom_module_1 $ npm init This utility will walk you through creating a package.json file. It only covers the most common items, and tries to guess sensible defaults. See `npm help json` for definitive documentation on these fields and exactly what they do. Use `npm install <pkg>` afterwards to install a package and save it as a dependency in the package.json file. Press ^C at any time to quit. package name: (node_modules) custom_module_1 version: (1.0.0) description: This is a custom node module just for example entry point: (index.js) test command: make test.js git repository: keywords: test example author: jerry zhao license: (ISC) Apache Sorry, license should be a valid SPDX license expression (without "LicenseRef"), "UNLICENSED", or "SEE LICENSE IN <filename>" and license is similar to the valid expression "Apache-2.0". license: (ISC) ISC About to write to /Users/zhaosong/Documents/WorkSpace/dev2qa.com-example-code/JavaScriptExampleWorkspace/NodeJSWorkspace/AsyncExecute/node_modules/package.json: { "name": "custom_module_1", "version": "1.0.0", "description": "This is a custom node module just for example", "main": "index.js", "scripts": { "test": "make test.js" }, "keywords": [ "test", "example" ], "author": "jerry zhao", "license": "ISC" } Is this OK? (yes) - After running the above code, you can see the custom module’s package.json file is created in node_modules/custom_module_1 directory with the below content.
- package.json file content example.
{ "name": "custom_module_1", "version": "1.0.0", "description": "This is a custom node module just for example", "main": "index.js", "scripts": { "test": "make test.js" }, "keywords": [ "test", "example" ], "author": "jerry zhao", "license": "ISC" }
3. Publish Custom NPM Module To NPM Repository.
- If you want to publish the created custom node module to the npmjs.com repository. You can execute the command $ npm adduser to achieve it.
$ npm adduser Username: jerry-zhao Password: Email: (this IS public) [email protected] Logged in as jerry-zhao on https://registry.npmjs.org/.
- This command will add a user in the npmjs.com repository, just follow the prompt and input related user info.
- Please note npmjs.com will send a verification email to your email box to verify that you are a real valid user.
- Remember the user name and password carefully, you will use them later.
- Then execute command $ npm publish in node_modules/custom_module_1 directory to publish the node module to npmjs.com repository.
- After that login to www.npmjs.com with the just-created user name and password and then you can see your NPM module in it.