title: Property 'forEach' does not exist on type 'void'
body: <p>The following code is: 1. Reading a folder. 2. Merging and auto-cropping images. 3. Saving the final images into png files.</p>
  <pre><code>const filenames = fs.readdirSync('./in').map(filename =&gt; {
    return path.parse(filename).name
  })
  
  const finalImages = filenames.forEach(async filename =&gt; {
    const bottomImage = await jimp.read(`./in/${filename}.png`)
    const topImage = await jimp.read('./dots.png')
    const file = bottomImage
      .composite(topImage, 0, 0)
      .autocrop(false)
    return {
      filename,
      file
    }
  })
  
  finalImages.forEach((finalImage: any) =&gt; {
    finalImage.file.write(`./out/${finalImage.filename}.png`)
  })
  </code></pre>
  <p>I'm getting this typescript error:</p>
  <p><a href="https://i.stack.imgur.com/WyKmc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WyKmc.png" alt="enter image description here" /></a></p>
  <blockquote>
  <p>Property 'forEach' does not exist on type 'void'.</p>
  </blockquote>
  <p>What could be the reason, and how to fix it?</p>