Webpack-dev-server not refreshing the page, why?

Question

JavaScript

https://github.com/DmitriiKholodov/exmo.me-api.git
Good evening, there is a simple structure:

exmo.me-api/
├── src/
│        ├── exmo-api.js
│        └── index.js
├── node-modules/
│        ├──  ...
├── index.html
├── package.json
├── package-lock.json
├── webpack.config.js
├── README.md
├── LICENSE.md

package.json

{
  "name": "exmo.me-api",
  "version": "1.0.0",
  "description": "getting data from public exmo.me api to your project",
  "main": "script.js",
  "scripts": {
    "dev": "webpack-dev-server --mode development --open --watch",
    "build": "webpack --mode production"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/DmitriiKholodov/exmo.me-api.git"
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/DmitriiKholodov/exmo.me-api/issues"
  },
  "homepage": "https://github.com/DmitriiKholodov/exmo.me-api#readme",
  "devDependencies": {
    "path": "^0.12.7",
    "webpack": "^4.18.0",
    "webpack-cli": "^3.1.0",
    "webpack-dev-server": "^3.1.8"
  },
  "dependencies": {}
}

connected webpack with the following config
webpack.config.js

let path = require('path');

let conf = {
  entry: path.resolve(__dirname, './src/index.js'),
  output: {
    path: path.resolve(__dirname, './dist'),
    filename: 'main.js',
    publicPath: 'dist/'
  },
  devServer: {
      hot: true
  }
};

module.exports = conf;

exmo-api.js

'use strict'

const baseUrl = 'https://api.exmo.com/v1/' // {api_name}?{api_params}

function getData(url) {
  fetch(url)
    .then(function(response) {
      return response.json()
    })
    .then(function(data) {
    	  return data
    })
    .catch(alert)
}
  

const exmo = {}

exmo.ticker = function ticker() {
  const url = baseUrl + 'ticker'
  return getData(url) 
} // example - https://api.exmo.com/v1/ticker
exmo.trades = function trades(...pairs){
  const url = baseUrl + 'trades/' + '?pair=' + pairs
  return getData(url)
} // example - https://api.exmo.com/v1/trades/?pair=BTC_USD,BTC_EUR
exmo.order_book = function order_book(limit, ...pairs){
  const url = baseUrl + 'trades/' + '?pair=' + pairs + '&limit=' + limit
  return getData(url)
} // example - https://api.exmo.com/v1/order_book/?pair=BTC_USD,BTC_EUR&limit=1000
exmo.pair_settings = function pair_settings(){
  const url = baseUrl + 'pair_settings'
  return getData(url)
} // example - https://api.exmo.com/v1/pair_settings
exmo.currency = function currency(){
  const url = baseUrl + 'currency'
  return getData(url)
} // example - https://api.exmo.com/v1/currency

let v = function a(a,b) {
  return a + b
}

export default { v };

index.js

'use strict'

import v from './exmo-api';

let f = v(3,5)
alert("asd")
console.log(f);

As a result, when you run npm run dev, everything starts successfully, localhost opens, changes in / src are tracked (but the page does not reload).
in the console at startup, not everything is so smooth -

everything else is not worked out

alert("asd")
console.log(f)

Advise something, never worked with it earlier. Thank you!

Answer 1

when I run npm run build I get a working main.js with the result

console.log(f) 
alert("asd")

when running npm run dev there is console.log(f)neitheralert("asd")