Jest test coverage output contains no data

Question

I am unit testing in React using Jest. When I run npm test the test cases pass, but the coverage code does not contain any data:

How can I see the code coverage data?

My Component is:

import React, { Component } from 'react';
import Tooltip from '@material-ui/core/Tooltip';

export default class HeaderCreate extends Component {

  render() {

    const { name, description, closeRightSection } = this.props;

    return (

      <div className="header">
        <h1 className="header-text" title={name} data-testid="header">{name}</h1>
        <p data-testid= "description-para">{description}</p>

        <Tooltip title="Close Section">
          <div className="icon-close">
            <i className="material-icons" onClick={() => closeRightSection()} data-testid="id">close</i>
          </div>
        </Tooltip>
      </div>
    )
  }
}

Unit Test Case

import React from 'react'
import { render , fireEvent} from "@testing-library/react";

import HeaderCreate from '../components/createHeader';


test("render header correctly", () => {
    const { getByTestId } = render(<HeaderCreate name="My Name is Test"></CreateHeader>);
    expect(getByTestId('header').textContent).toBe('My Name is Test')
});

test("render Description Paragraph correctly", () => {
    const { getByTestId } = render(<HeaderCreate description="Hi I am Description box"></CreateHeader>);
    expect(getByTestId('description-para').textContent).toBe('Hi I am Description box')
});

test("render close tooltip correctly", () => {
    const { getByTestId } = render(<HeaderCreate closeRightSection=""></CreateHeader>);
    expect(getByTestId('id')).toBeTruthy();
});

Answer 1

Try this:

npm run test --coverage --watchAll=false

It's very likely a jest bug as mentioned here.