Testing React Apps with Jest and React Testing Library/

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Checking Arrays

Checking Arrays

Learn various approaches for checking an array result in a test in this lesson.

We'll cover the following...

Checking the length of the array

The project for this lesson contains a function called searchPeople, which returns matched people objects in an array for some criteria. A test has been partially implemented that checks whether the correct array is returned when a first name is passed as the criteria.

A copy of the starter project is in the code widget below:

const people = [
  {
    id: 1,
    firstName: "Bill",
    lastName: "Peters",
  },
  {
    id: 2,
    firstName: "Jane",
    lastName: "Sheers",
  },
];

function wait(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

export async function searchPeople(criteria) {
  await wait(200);
  const found = people.filter(
    (p) =>
      p.firstName.toLowerCase().indexOf(criteria.toLowerCase()) > -1 ||
      p.lastName.toLowerCase().indexOf(criteria.toLowerCase()) > -1
  );
  return found;
}
Partially implemented test

As an exercise, use the toBe matcher in the test to check the people array has a ...