Exception handling

Hello!

There is one more issue: exception.zip

What expects: that I catch exception and send it message to user. What happens:

/node_modules/bpmn-engine/lib/mapper.js:9
    throw new Error(`Unknown activity type ${type}`);
    ^

Error: Unknown activity type bpmn:SignalEventDefinition

and it exception kills whole server process.

Wrapping any part of my code by try {...} catch(e) {...} has no result, because exception produced somewhere in async code of bpmn-engine lib.

[paed01]

Not in master unfortunately. Sorry about that. But I have considered it when refactoring the engine in develop.

There is a deprecated work-around if you are running on node-6* https://nodejs.org/dist/latest-v6.x/docs/api/domain.html. Not elegant but could work.

[neonxp]

Oh, it fully resolves my trouble! Thank you. For history, my resolution:

import d from 'domain';
...
const d = domain.create();
d.on('error', (er) => {
  console.log(`Engine error: ${er.message}`);
  // Do cleanup here and send error to client
});
d.run(() => {
  const engine = new Bpmn.Engine({
    name: 'Script',
    source: XML,
    moddleOptions: {camunda}
  });
  engine.execute(
    this.getOptions(),
    (err, definition) => {
      debug(
        'Bpmn definition definition started with variables',
        definition && definition.getProcesses()[0].context.variables
      );
    });
});