Customise node module and build is not working

I have to customize an npm module that is available on GitHub.For this, i have done the following steps.

1.Download the entire file from https://github.com/HsuanXyz/ion2-calendar

2.install modules using npm install

3.made some changes on the files located in ./src/components

4.for creating the build npm run-script build

the 4’th step executed and dist folder was created without having the change I have added, and the entire changes in my src were gone and old code was there.what is wrong with this? do i need to do any other steps?

Post the package.json.

package.json

{
  "name": "ion2-calendar",
  "version": "2.1.6",
  "description": "A date picker component for ionic2 ",
  "main": "./dist/index.js",
  "typings": "./dist/index.d.ts",
  "scripts": {
    "start": "cd ./dev && ionic serve",
    "clean:dist": "rm -rf dist",
    "demo:link": "npm link && cd ./demo && npm link ion2-calendar",
    "demo:serve": "cd ./demo && ionic serve",
    "build": "run-s clean:dist build:copy-sources build:ts && gulp copy-scss ",
    "build:ts": "tsc && ngc",
    "build:copy-sources": "gulp copy-sources",
    "test": "echo \"Error: no test specified\"",
    "lint": "tslint -c tslint.json 'src/**/*.ts'"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/HsuanXyz/ion2-calendar.git"
  },
  "devDependencies": {
    "@angular/common": "4.4.6",
    "@angular/compiler": "4.4.6",
    "@angular/compiler-cli": "4.4.6",
    "@angular/core": "4.4.6",
    "@angular/forms": "4.4.6",
    "@angular/http": "4.4.6",
    "@angular/platform-browser": "4.4.6",
    "@angular/platform-browser-dynamic": "4.4.6",
    "gulp": "^3.9.1",
    "gulp-bump": "^3.0.0",
    "ionic-angular": "3.7.1",
    "ionicons": "~3.0.0",
    "moment": "^2.19.1",
    "npm-run-all": "^4.1.2",
    "rxjs": "5.5.2",
    "tslint": "~5.7.0",
    "tslint-eslint-rules": "^4.1.1",
    "typescript": "^2.5.3",
    "zone.js": "0.8.18"
  },
  "keywords": [
    "ionic2",
    "calendar",
    "Datepicker",
    "date-range"
  ],
  "author": "HsuanLee",
  "license": "MIT",
  "dependencies": {
    "moment": "^2.19.3"
  }
}

Ionic no longer uses gulp, so the build scripts look out of date. I’ve never used gulp either, so I don’t know the best way to fix this. But your step 4 looks wrong. If I had this problem, I’d change the scripts section so it looked like an Ionic starter app, and see what effect that had.

but this plugin look like updated in 3 weeks https://www.npmjs.com/package/ion2-calendar

Maybe because its focus is Ionic 2? Ionic switched to gulp “permanently” for Ionic 2, but now, in Ionic 3, ionic app-scripts is building with webpack 3.6.