Copy canvas to clipboard

copy_canvas.js

// 1. Save this to a bookmarklet with https://make-bookmarklets.com/
// 2. Run bookmarklet
// 3. Find the canvas in developer tool and "use it in console"
// 4. Run `copyCanvas(temp0)`
// 5. Click anywhere on the webpage (to workaround the restriction that
//    clipboard writes must be triggered some user interaction)
window.copyCanvas = canvas => (
  canvas.toBlob(blob => (
    window.addEventListener("click", () => (
      navigator.clipboard.write([
          new ClipboardItem({
              [blob.type]: blob
          })
      ]).then(() => console.log("Copied!"))
    ), { once: true })
  ))
)