Types of property 'theme' are incompatible in cucumber-html-reporter

Question

Hi I'm new to cucumber framework and I was trying to generate a html report using cucumber-html-reporter. But the 'theme' property in options of cucumber-html-reporter is giving me an error telling that Type 'string' is not assignable to type '"bootstrap" | "hierarchy" | "foundation" | "simple"'. But I have given 'theme' as a string type because in the docs they have mentioned as string type. Can anyone please help me where I'm going wrong?

This is how my cucumber config.ts look like:

import { Config } from 'protractor';
import * as reporter from 'cucumber-html-reporter';


export let config: Config = {
  directConnect: true, 
  seleniumAddress: 'http://localhost:4444/wd/hub', 
  framework: 'custom',
  frameworkPath: require.resolve('protractor-cucumber-framework'),
  specs: ['../features/demo.feature'], 
  capabilities:
    {
      browserName: "chrome", 
      'goog:chromeOptions': {
        w3c: false
       },
    }, 
  cucumberOpts: {
    tags: "@CalculatorTesting",
    format: "json:./cucumberReport.json", 
    // html reporter
    onComplete: () => {
      let options = {
        theme: "hierarchy",
        jsonFile: './tmp/cucumber_report.json',
        output: '../cucumber_report.html',
        reportSuiteAsScenarios: true,
        scenarioTimestamp: true,
        launchReport: true,
        metadata: {
            "App Version":"0.3.2",
            "Test Environment": "STAGING",
            "Browser": "Chrome  54.0.2840.98",
            "Platform": "Windows 10",
            "Parallel": "Scenarios",
            "Executed": "Remote"
        }
    };
    reporter.generate(options);
    }, 

    require: [
      './stepDefinitions/*.js'
    ]
  }
};

Answer 1

From index.d.ts of cucumber-html-reporter as following, I think this syntax theme: 'bootstrap' | 'hierarchy' | 'foundation' | 'simple' should be supported when Nodejs version high than specific one.

What's the nodejs version you used to run test?

interface Options {
  theme: 'bootstrap' | 'hierarchy' | 'foundation' | 'simple',
  jsonFile?: string,