When I was doing first steps in k6, I wanted to see one example with values. 
So here is the sample, where my 'http://localhost:3000/#/' = OWASP Juice Shop (free web page for security testing training. Page that you can install and run locally):
import http from 'k6/http';
import { check, sleep } from 'k6';
import { Counter, Rate } from 'k6/metrics';
export const requests = new Counter('http_reqs');
const myFailRate = new Rate('failed requests');
export const options = {
  scenarios: {
    main: {  //Test Case 1
      executor: 'constant-vus',
      exec: 'main',
      vus: 30,
      duration: '90s',
    },
    login: {   //Test Case 2
      executor: 'constant-vus',
      exec: 'login',
      vus: 10,
      startTime: '15s',
      duration: '90s',
    },
    about: {   //Test Case 3
      executor: 'shared-iterations',
      exec: 'about',
      vus: 5,
      iterations: 50,
      startTime: '30s',
      maxDuration: '90s',      
    },
  }
}
export function main() { //Test Case 1
  const res = http.get('http://localhost:3000/#/');
  sleep(Math.random() * 5);
  myFailRate.add(res.status !== 200);
  const checkRes = check(res, {
    'status was 200': (r) => r.status == 200,
    'response body contains <OWASP Juice Shop>': (r) => r.body.indexOf('OWASP Juice Shop') !== -1,
    'duration was <=200ms(miliseconds)': (r) => r.timings.duration <= 200,
  });
}
export function login() { //Test Case 2
  const res = http.get('http://localhost:3000/#/login');
  sleep(Math.random() * 2);  
  myFailRate.add(res.status !== 200);
  const checkRes = check(res, {
    'status was 200': (r) => r.status == 200,
    'response body contains <Login1>': (r) => r.body.includes("Login"),  //Failure expected here. Not found, Yet I see it on the page
    'response body contains <Login2>': (r) => r.body.includes('Login'),  //Failure expected here. Not found, Yet I see it on the page
    'response body contains <Login3>': (r) => r.body.indexOf('Login') !== -1,  //Failure expected here. Not found, Yet I see it on the page
    'response body contains <Login4>': (r) => r.body.indexOf("Login") !== -1,  //Failure expected here. Not found, Yet I see it on the page
    'response body contains <OWASP Juice Shop> in the Login page': (r) => r.body.indexOf('OWASP Juice Shop') !== -1,
    'duration was <=200ms(Login)': (r) => r.timings.duration <= 200,
  });
}
export function about() { //Test Case 3
  const res = http.get('http://localhost:3000/#/about')
  sleep(Math.random() * 5);
  myFailRate.add(res.status !== 200);
  const checkRes = check(res, {
    'status was 200': (r) => r.status == 200,
    'response body contains <About Us>': (r) => r.body.includes('About Us'), //Failure expected here. Not found, Yet I see it on the page
    'response body contains <OWASP Juice Shop> in the About page': (r) => r.body.indexOf('OWASP Juice Shop') !== -1,
    'duration was <=200ms(About)': (r) => r.timings.duration <= 200,
  });
}
P.S. Solution tested with k6 v0.43.1 (2023.04.20)