Test BPMN with Deno

[oberien]

BPMN is a standard for business process specification. There is a bpmn-js library for creating and rendering the flows, which could be used for integration into heradoc. However, it would be nice if we were able to avoid nodejs as a required system dependency. One possibility could be using deno, a work in progress js / ts runtime based on V8. It is being worked on by the creator of nodejs and written in rust. We should test if it is possible to run bpmn-js with deno without any system dependencies.

Problem 1 - It should run in Deno or at least NodeJS

• only render implementation I found was bpmn-js
• only works in browsers
• uses ES6 directory-imports which aren't supported by nodejs or deno
• could be fixed by packing its source into a single file (see Problem 2)
• only cli-tool I could find was bpmn-to-image which internally just launches a headless browser to use bpmn-js in the browser for rendering

Problem 2 - It should be a single file

• heradoc shouldn't carry around hundreds of small js files which import each other
• should be packed into a single file instead
• js packing frameworks are plenty but one more horrific than the other
• I wasn't able to get a single js file as output with several I tried in less than an hour each
• why is this so hard?!?!?!

Problem 3 - Should include all dependencies

• similar to Problem 2 the single js file needs to include all dependencies
• → we need to use a packer
• → back to Problem 2…

One idea I haven't tried yet is to use bpmn-js-cli as a basis for packing. Its readme states

Use an ES module aware bundler such as Webpack or Rollup to bundle it for the browser.