server.js

const express = require('express');
const fs = require('fs');
const initSqlJs = require('sql.js');

initSqlJs().then((sqlite) => {
  const filebuffer = fs.readFileSync('db/usda-nnd.sqlite3');

  const db = new sqlite.Database(filebuffer);

  const app = express();

  app.set('port', process.env.PORT || 3001);

  // Express only serves static assets in production
  if (process.env.NODE_ENV === 'production') {
    app.use(express.static('client/build'));
  }

  const COLUMNS = [
    'carbohydrate_g',
    'protein_g',
    'fa_sat_g',
    'fa_mono_g',
    'fa_poly_g',
    'kcal',
    'description',
  ];
  app.get('/api/food', (req, res) => {
    const param = req.query.q;

    if (!param) {
      res.json({
        error: 'Missing required parameter `q`',
      });
      return;
    }

    // WARNING: Not for production use! The following statement
    // is not protected against SQL injections.
    const r = db.exec(
      `
    select ${COLUMNS.join(', ')} from entries
    where description like '%${param}%'
    limit 100
  `,
    );

    if (r[0]) {
      res.json(
        r[0].values.map((entry) => {
          const e = {};
          COLUMNS.forEach((c, idx) => {
          // combine fat columns
            if (c.match(/^fa_/)) {
              e.fat_g = e.fat_g || 0.0;
              e.fat_g = (parseFloat(e.fat_g, 10)
              + parseFloat(entry[idx], 10)).toFixed(2);
            } else {
              e[c] = entry[idx];
            }
          });
          return e;
        }),
      );
    } else {
      res.json([]);
    }
  });

  app.listen(app.get('port'), () => {
    console.log(`Find the server at: http://localhost:${app.get('port')}/`); // eslint-disable-line no-console
  });
});