My data in Json file is not permanently saved (Express REST API) - json

Question

I built a REST API using Express, a JSON file (database), and deployed it on Heroku. I consume this API from my React.JS app which I run on localhost. It seems my data is not persist after I restart my React.JS app.
Here is my server.js file:
const express = require('express');
const bodyParser = require('body-parser');
const path = require('path');
const fs = require('fs');
const port = process.env.PORT || 3000;
const app = express();
app.use((req, res, next) => {
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
res.header('Access-Control-Allow-Methods', 'GET, PUT, POST, DELETE, PATCH, OPTIONS');
if (req.method === 'OPTIONS') {
res.send(200);
} else {
next();
}
});
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
// GET ALL TODOS
app.get('/api/todos', (req, res) => {
let data = '';
fs.readFile(path.resolve(__dirname, 'data.json'), (err, resp) => {
if (err) return console.log('Error::reading tasks from data.json file ', err);
data = JSON.parse(resp);
res.send(data.todos);
});
});
// GET A TODO
app.get('/api/todos/:id', (req, res) => {
fs.readFile(path.resolve(__dirname, 'data.json'), (err, resp) => {
if (err) return console.log('Error::reading tasks from data.json file ', err);
let data = JSON.parse(resp);
let todoData = data.todos.filter(todo => todo.id === parseInt(req.params.id))
if (todoData.length > 0) {
res.status(200).send(todoData[0]);
} else {
res.status(500).send({ message: 'Error: not found any task with that id' });
}
});
});
// POST A TODO
app.post('/api/todo', (req, res) => {
fs.readFile(path.resolve(__dirname, 'data.json'), (err, resp) => {
if (err) return console.log('Error::reading tasks from data.json file ', err);
const { id, task, status } = req.body
if (id && task && status) {
let json = JSON.parse(resp);
json.todos.push(req.body);
fs.writeFile(path.resolve(__dirname, 'data.json'), JSON.stringify(json), err => {
if (err) return console.log('Error::writing task to the data.json file ', err);
});
res.status(200).send({ message: 'Success: data have been added' });
} else {
res.status(500).send({ message: 'Error: all fields must be filled with data' })
}
});
});
// EDIT A TODO
app.put('/api/todo/:id', (req, res) => {
fs.readFile(path.resolve(__dirname, 'data.json'), (err, resp) => {
if (err) return console.log('Error::reading tasks from data.json file ', err);
const id = parseInt(req.params.id)
const { task, status } = req.body
if (task && status) {
let json = JSON.parse(resp);
let newTodo = json.todos.map(todo => {
if(todo.id === id) {
return {
id,
task,
status
}
} else {
return todo
}
})
let result = {
todos: newTodo
}
fs.writeFile(path.resolve(__dirname, 'data.json'), JSON.stringify(result), err => {
if (err) return console.log('Error::editing task to the data.json file ', err);
res.status(200).send({ message: 'Success: task have been edited' });
});
} else {
res.status(500).send({
message: 'Error: all fields must be filled with data'
})
}
});
});
// DELETE A TODO
app.delete('/api/todo/:id', (req, res) => {
fs.readFile(path.resolve(__dirname, 'data.json'), (err, resp) => {
if (err) return console.log('Error::reading tasks from data.json file ', err);
let json = JSON.parse(resp);
let isDataExist = json.todos.some(todo => todo.id === parseInt(req.params.id))
if (isDataExist) {
let leftTodo = json.todos.filter(todo => todo.id !== parseInt(req.params.id))
let result = {
todos: leftTodo
}
fs.writeFile(path.resolve(__dirname, 'data.json'), JSON.stringify(result), err => {
if (err) return console.log('Error::deleting task to the data.json file ', err);
res.status(200).send({ message: 'Success: a task has been deleted' });
});
} else {
res.status(500).send({ message: 'Error: a task you want to delete is not exist' })
}
});
});
app
.listen(port, () => {
console.info(`Your api server is running on http://localhost:${port}`);
})
.on('error', () => {
console.error('Error::server ', error);
});
I save the data in data.json file. You could see the logic in every API block URL / route. What are wrong in my server code?
Note: If you want to see my repo for this project: https://github.com/ridoansaleh/api

Answer 1

a JSON file (database)
A JSON file isn't a proper database, and Heroku's ephemeral filesystem makes this an especially bad choice: any changes you make to it will be lost the next time your dyno restarts. This happens frequently (at least once per day).
If you want to persist data permanently you need to use a proper client-server database. Heroku provides a hosted PostgreSQL service that has a free tier. I recommend starting there.