text: const path = require('path');
  const fs = require('fs');
  const { promisify } = require('util');
  
  const readFile = promisify(fs.readFile);
  
  async function loadPixels() {
    const filePath = path.resolve(__dirname, '../_data/pixels.json');
    const pixelJsonString = await readFile(filePath, 'utf8');
    return JSON.parse(pixelJsonString);
  }
  
  describe('pixels', () => {
    test('every username should only claim one pixel', async () => {
      const pixels = await loadPixels();
      const usernameSet = new Set();
      for (const pixel of pixels.data) {
        if (pixel.username !== '<UNCLAIMED>') {
          expect(usernameSet.has(pixel.username)).toBeFalsy();
        }
        usernameSet.add(pixel.username);
      }
    });
  });
  