code: def _js_repr(val):
      """Return a javascript-safe string representation of val"""
      if val is True:
          return "true"
      elif val is False:
          return "false"
      elif val is None:
          return "null"
      elif isinstance(val, OperatorMixin):
          return val._to_expr()
      else:
          return repr(val)
  
imports: from ..utils import SchemaBase
label_desc: Use image node_id 1 for calling a global function with example usage: _js_repr(val) and returns: str, str, str, val, repr