Interpreter fails if input value is "non-truthy"

[Marios]

An interpreted experiment will always return non-true values for non-truthy inputs, e.g. {userid: 0} or {userid: false}.

'use strict';

const planout = require('planout');

class Repro extends planout.Experiment {
  assign(params, args) {
    const script = {
      op: 'seq',
      seq: [
        {
          op: 'set',
          var: 'num_of_categories',
          value: {
            choices: {
              op: 'array',
              values: [1, 5, 10],
            },
            unit: {
              op: 'get',
              var: 'userid',
            },
            op: 'uniformChoice',
          },
        },
      ],
    };

    const interpreterInstance = new planout.Interpreter(
      script,
      this.getSalt(),
      args
    );
    const results = interpreterInstance.getParams();

    Object.keys(results).forEach(result => {
      params.set(result, results[result]);
    });
    return interpreterInstance.inExperiment;
  }

  // The equivalent works
  //assign(params, args) {
  //  params.set('num_of_categories', new planout.Ops.Random.UniformChoice({choices: [1,5,10], 
  //                                                                       'unit': args.userid})); 
  //}

  configureLogger() {
    return;
  }

  setup() {
    this.name = 'exp0';
  }

  log(event) {
    console.log(event);
  }

  getParamNames() {
    return this.getDefaultParamNames();
  }

  previouslyLogged() {
    return this._exposureLogged;
  }
}

// failure: will always return undefined
const try1 = new Repro({userid: 0});
console.log(try1.get('num_of_categories'));

// works
const try2 = new Repro({userid: '0'});
console.log(try2.get('num_of_categories'));

// works
const try3 = new Repro({userid: 1});
console.log(try3.get('num_of_categories'));

[Guy Aridor]

Thanks for reporting this, I'll look into it tonight