Unit tests for the home page.

Getting Started With Gatsby Testing -Unit tests for the home page.

import React from "react"
import { render } from "@testing-library/react"
import { useStaticQuery } from "gatsby"
 
import BlogIndexDetails from "../index"
 
describe("BlogIndex component", () => {
  beforeEach(() => {
    useStaticQuery.mockReturnValue({
      site: {
        siteMetadata: {
          title: `Gatsby Starter Blog for Freshers`,
          description: A starter blog demonstrating what Gatsby can do and the features offered. `,
          social: {
            twitter: `Irshad`,
          },
        },
      },
    })
  })
  it("renders the tests correctly", async () => {
    const mockData = {
      site: {
        siteMetadata: {
          author: "xyz",
        },
      },
      allMarkdownRemark: {
        nodes: [
          {
            excerpt: "This is my first attempt at excerpt writing",
            fields: {
              slug: "first-slug",
            },
            frontmatter: {
              date: "May 3, 2022",
              title: "My first blog post for readers",
              description: "My awesome blog description for readers",
            },
          },
          {
            excerpt: "This is my second attempt at excerpt writing",
            fields: {
              slug: "second-slug",
            },
            frontmatter: {
              date: "Nov 12, 2022",
              title: "My second blog post for reader friends",
              description: "My awesome second blog description for reader friends",
            },
          },
        ],
      },
    }
 
    const { getByTestId } = render(
      <BlogIndex data={mockData} location={window.location} />
    )
 
    const { nodes } = mockData.allMarkdownRemark
    const post1 = "first-slug-link"
    const post2 = "second-slug-desc"
 
    expect(getByTestId(post1)).toHaveTextContent(nodes[0].frontmatter.title)
    expect(getByTestId(post2)).toHaveTextContent(
      nodes[1].frontmatter.description
    )
    expect(nodes.length).toEqual(5)
  })
})