Author here - it does but it doesn't, which is why it doesn't always work so well. It never actually keeps track of the shapes in a seperate data model - the text itself is the only data model. When you resize, it retraces out the lines that need editing. I did this as the expected use case is for diagrams in code, where diagrams may be copy pasted in and out of the tool and I'd lose any underlying models that I was working with. For fun: https://github.com/lewish/asciiflow2/blob/master/js-lib/draw...