ojm OlivierJM

The introduction to Reactive Programming you've been missing

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.


	it('removes the zm country code', () => {
	expect(removePrefix("260923423")).toBe("923423")
	})

	it('removes the starting zero', () => {
	expect(removePrefix("0923423")).toBe("923423")
	})

	// in the above tests you can see that the end result is all the same.

	// zambian mobile numbers start with 09x in case the user typed it start with a 2
	// then its a country code prefixed

	// es6
	const removePrefix = num => num[0] == 2 ? num.substring(3) : num[0] == 0 ? num.substring(1) : num;

	// es5
	function removePrefix(num){
	if(num[0] == 2){ // check if it starts with a 2
	return num.substring(3) // remove numbers up to index 2 of the value

	import { removeSymbol } from '../utils'

	it("should remove the + symbol if it exists", () => {
	expect(removeSymbol("+260")).toBe("260")
	})

	it("should return the given value if not + symbol found", () => {
	expect(removeSymbol("500")).toBe("500")
	})
	// since the argument should be a string, let's test that as well

	function removeSymbol(number){
	// make sure we are getting a string
	if (typeof number !== "string") throw new TypeError("Expected string");
	// check if the number has the + sign and remove it
	if(number.includes("+")){
	return number.replace(/\+/gi, "")
	}
	return number
	}

	function add(a, b){
	return a + b
	}
	// test if the add really adds two numbers
	it('should add two given numbers', () => {
	expect(add(2, 5)).toBe(7)
	})

	import * as R from 'ramda'

	const appendCountryCode = R.curry((number, code) => `${code} ${number}`);

	import React, { useState } from "react";

	const removeSymbol = num => (num.includes("+") ? num.replace(/\+/gi, "") : num);
	const hasPrefix = num => num[0] == 2 ? num.substring(3) : num[0] == 0 ? num.substring(1) : num;

	function App() {
	const [number, setNumber] = useState("");
	function parseNumber({ target: { value } }) {
	setNumber(value);
	}

	function parseText(text) {
	let filterSpace = item => item.length > 1;
	let spacedWords = text
	.split(" ")
	.filter(filterSpace)
	.map(word => `${word} `);

	spacedWords.map((word, i) => {
	if (!word.indexOf("_")) {
	let newWord = <span style={{ color: "blue" }}>{word.substring(1)}</span>;

	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width">
	<title>JS Bin</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.js"></script>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/expect/1.20.2/expect.js"></script>
	</head>
	<body>