Getting Started With Gatsby Testing -

Getting Started With Gatsby Testing - Writing the unit tests for the Sample component.

// components/__tests__/sample.js
import React from "react"
import { render } from "@testing-library/react"
import { useStaticQuery } from "gatsby"
 
import Helmet from "react-helmet"
import Sample from "../sample"
 
describe("Sample component", () => {
  beforeAll(() => {
    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", () => {
    const mockTitle = "All posts | Gatsby Starter Blog for Freshers"
    const mockDescription = "A starter blog demonstrating what Gatsby can do and the features offered."
    const mockTwitterHandler = "Irshad"
 
    render(<SEO title="All posts" />)
    const { title, metaTags } = Helmet.peek()
 
    expect(title).toBe(mockTitle)
    expect(metaTags[0].content).toBe(mockDescription)
    expect(metaTags[5].content).toBe(mockTwitterHandler)
    expect(metaTags.length).toBe(10)
  })
})