CodeMirror electricInput does not match expression with leading whitespace

Question

In my custom mode for CodeMirror, I want the electricInput event to fire when the user types a line starting with the word bank (with optional leading whitespace).

I have electricInput set up like this: electricInput: /\s*bank$/i

The event DOES fire when the user types bank at the beginning of a line. It does NOT fire when there are spaces before the word bank. Why?

(the RegEx seems to be fine. I have a grammar rule in that mode with the same RegEx, and it matches the token as expected, regardless of leading white spaces:

CodeMirror.defineSimpleMode("myMode", {
  start: [
    {regex: /\s*bank$/i, token: 'bank', sol: true, indent: true}

Answer 1

Thanks to Marijn's kind help on the CodeMirror discussions forum, I was able to solve this: a custom indent function needs to be passed to defineSimpleMode. Then, we still need to set electricInput (because otherwise the indent function does not get called when typing bank). But no event handler for onElectricInput is required.

CodeMirror.defineSimpleMode("myMode", {
  start: [
    ...
  ],
  meta: {
    electricInput: /\s*bank$/i,
    indent: function (state, textAfter, line) {
      if (textAfter.substring(0, 4).toLowerCase() === 'bank') return 0
      return 2;
    }
  }  
});