expo-api-routes

Here's a set of API routes for a fitness tracking application in Expo that handles user authentication, workout logging, and data synchronization with Firebase. The routes include JWT-based authentication, input validation, and error handling.

```javascript
// routes/auth.js
const express = require('express');
const router = express.Router();
const jwt = require('jsonwebtoken');
const bcrypt = require('bcrypt');
const User = require('../models/User');

router.post('/register', async (req, res) => {
  try {
    const { email, password } = req.body;
    const hashedPassword = await bcrypt.hash(password, 10);
    const user = new User({ email, password: hashedPassword });
    await user.save();
    res.status(201).send('User registered successfully');
  } catch (error) {
    res.status(400).send('Error registering user');
  }
});

router.post('/login', async (req, res) => {
  try {
    const { email, password } = req.body;
    const user = await User.findOne({ email });
    if (!user) {
      return res.status(401).send('Invalid credentials');
    }
    const isMatch = await bcrypt.compare(password, user.password);
    if (!isMatch) {
      return res.status(401).send('Invalid credentials');
    }
    const token = jwt.sign({ userId: user._id }, process.env.JWT_SECRET, { expiresIn: '1h' });
    res.send({ token });
  } catch (error) {
    res.status(500).send('Error logging in');
  }
});

module.exports = router;

// routes/workouts.js
const express = require('express');
const router = express.Router();
const Workout = require('../models/Workout');
const auth = require('../middleware/auth');

router.use(auth);

router.post('/', async (req, res) => {
  try {
    const { type, duration, calories } = req.body;
    const workout = new Workout({ type, duration, calories, user: req.user._id });
    await workout.save();
    res.status(201).send(workout);
  } catch (error) {
    res.status(400).send('Error creating workout');
  }
});

router.get('/', async (req, res) => {
  try {
    const workouts = await Workout.find({ user: req.user._id });
    res.send(workouts);
  } catch (error) {
    res.status(500).send('Error fetching workouts');
  }
});

module.exports = router;

// routes/sync.js
const express = require('express');
const router = express.Router();
const Workout = require('../models/Workout');
const auth = require('../middleware/auth');
const admin = require('firebase-admin');

router.use(auth);

router.post('/firebase', async (req, res) => {
  try {
    const { data } = req.body;
    const workout = new Workout({ ...data, user: req.user._id });
    await workout.save();
    await admin.firestore().collection('workouts').add({ ...data, userId: req.user._id });
    res.status(201).send(workout);
  } catch (error) {
    res.status(400).send('Error syncing workout');
  }
});

module.exports = router;
```