app.js

let express = require('express')
let app = express()
let datas = require('./datas.json')
let fs = require('fs');
var cors = require('cors');

/********
 * 
 * Utilisez Nodemon.js
 * https://nodemon.io/
 * 
 *********/

// use it before all route definitions
app.use(cors({ origin: 'http://localhost:8080' }));


/**
 ****************************************** API ************************************************ 
 */


/**
 * "/" Home
 */
app.get('/', function (req, res) {
	res.json(datas);
});

/**
 * Limit de à
 */
app.get('/:debut-:fin', function (req, res) {
	let debut = req.params.debut;
	let fin = req.params.fin;

	let tab = datas.splice(debut, fin);
	res.json(tab);
});

/**
 * "/send": Add a posts 
 */
app.post('/', function (req, res) {

	res.json(datas);
});


/**
 * "/visible" visible
 */
app.get('/visible', function (req, res) {
	let visibles = datas.filter((task) => task.visible == true);
	res.json(visibles);
});

/**
 * "star" >= 7
 */
app.get('/stars', function (req, res) {
	let stars = datas.filter((task) => task.visible >= stars);
		return stars
});

/**
 * Route search
 */
app.get('/search/:word', function (req, res) {
	let word = req.params.word;
	if (!word) {
		res.json(datas);
	}
	let regex = new RegExp(word, 'i')
	let filtrer = datas.filter((task) => regex.test(task.title));

	res.json(filtrer);
});

/**
 * Visibilite
 */
app.get('/visibilite/:visible', function (req, res) {
	let visibility = req.params.visible;
	let filtrer = datas.filter((task) => task.visible == visibility);

	res.json(filtrer);
});



/**
 * Change title
 */
app.get('/change-title/:id/:title', function (req, res) {
	let id = req.params.id;
	let title = decodeURIComponent(req.params.title); // parse Boolean

	let post = datas.find((elt) => elt.id == id); // get reference of datas
	post.title = title;

	let json = JSON.stringify(datas);
	fs.writeFile('datas.json', json, 'utf8', () => {
		res.json(datas);
	});
});

app.get('/change-visibility/:id/:visible', function (req, res) {
	let id = req.params.id;
	let visible = req.params.visible === "true"; // parse Boolean
	let post = datas.find((elt) => elt.id == id); // get reference of datas
	post.visible = visible;

	let json = JSON.stringify(datas);
	fs.writeFile('datas.json', json, 'utf8', () => {
		res.json(datas);
	});
});

/**
 * Add post
 */
app.get('/post', function (req, res) {
	datas.push({
				"id": datas.length + 1,
				"title": "Test...",
				"visible": true,
				"note": 8
	});
	let json = JSON.stringify(datas);
	fs.writeFile('datas.json', json, 'utf8', () => {
		res.json(datas);
	});

});



app.listen(3000, function () {
	console.log('Le serveur des taches est lancé!')
})

datas.json

[
	{
		"id": 1,
		"title": "Blablablabla...",
		"category": "Sport",
		"visible": false,
		"note": 2
	},
	{
		"id": 2,
		"title": "ici...",
		"category": "Sport",
		"visible": false,
		"note": 5
	},
	{
		"id": 3,
		"title": "lala...",
		"category": "Insolite",
		"visible": true,
		"note": 7
	},
	{
		"id": 4,
		"title": "Test...",
		"category": "Insolite",
		"visible": true,
		"note": 8
	},
	{
		"id": 5,
		"title": "Test...",
		"category": "Insolite",
		"visible": true,
		"note": 8
	},
	{
		"id": 6,
		"title": "Test...",
		"category": "Economie",
		"visible": true,
		"note": 8
	},
	{
		"id": 7,
		"title": "Test...",
		"category": "Economie",
		"visible": true,
		"note": 8
	},
	{
		"id": 8,
		"title": "Alpha...",
		"category": "Cinema",
		"visible": false,
		"note": 6
	},
	{
		"id": 9,
		"title": "Beta...",
		"category": "Cinema",
		"visible": true,
		"note": 10
	},
	{
		"id": 10,
		"title": "coucou tu veux",
		"category": "People",
		"visible": true,
		"note": 8
	},
	{
		"id": 11,
		"title": "Omega...",
		"category": "People",
		"visible": true,
		"note": 2
	},
	{
		"id": 12,
		"title": "Test...",
		"visible": true,
		"note": 8
	},
	{
		"id": 13,
		"title": "Test...",
		"visible": true,
		"note": 8
	},
	{
		"id": 14,
		"title": "Test...",
		"visible": true,
		"note": 8
	},
	{
		"id": 15,
		"title": "Test...",
		"visible": true,
		"note": 8
	},
	{
		"id": 16,
		"title": "Test...",
		"visible": true,
		"note": 8
	},
	{
		"id": 17,
		"title": "Test...",
		"visible": true,
		"note": 8
	},
	{
		"id": 18,
		"title": "Test...",
		"visible": true,
		"note": 8
	}
]

package.json

{
  "dependencies": {
    "cors": "^2.8.3",
    "express": "^4.15.2"
  }
}