Arquivo que contém as rotas.

index.js

const express = require('express');
const { uuid, isUuid } = require('uuidv4');

const projects = [];

const app = express();

app.use(express.json());

app.get('/projects', (request, response) => {
	console.log(3);
	const { title, owner } = request.query;
	
	const results = title ? projects.filter(project => project.title.includes(title)) : projects;

	return response.json(results);
});

app.post('/projects', (request, response) => {
	const { title, owner } = request.body;

	const project = { id: uuid(), title, owner };

	projects.push(project);

	return response.json(project);
});

app.put('/projects/:id', (request, response) => {
	const { id } = request.params;

	let projectIndex = projects.findIndex( project => project.id === id );

	if ( projectIndex < 0 ) return response.status(400).json({ error: 'Project not found.' });

	const project = {
		id,
		title,
		owner
	};

	projects[projectIndex] = project;

	return response.json(project); 
});

app.delete('/projects/:id', (request, response) => {
	const { id } = request.params;

	let projectIndex = projects.findIndex( project => project.id === id );

	if ( projectIndex < 0 ) return response.status(400).json({ error: 'Can not delete.' });

	projects.splice(projectIndex, 1);

	return response.send();
});

app.listen(3333, () => {
	console.log('back-end started! 🚀');
});