This is a Node.js version of the javascript (ES2015) version of ASCIImage by Charles Parnot. ASCIImage lets you create icons by defining some control points for drawing lines, paths, and circles. You can also style each shape individually. Read all about the original project, then read about cocoscii, then come back here.
node-cocoscii includes a commandline tool bin/saciimage.js for translating .asciimage files into png. It accepts .asciimage data via stdin, and outputs to its stdout a PNG image representation of the image.
npm install -g node-cocoscii
cat ./examples/cross.asciimage | asciimage.js | open -f -a /Applications/Preview.app
You'll see something like as follows:
There are also a number of other implementations of ASCIImage available at ASCIImage.org.