jest.config.js

const modulesToBeIgnored = ["gatsby", "gatsby-material-ui-components", "react-helmet"].join("|")

module.exports = {
  transform: {
    "^.+\\.jsx?$": `<rootDir>/jest-preprocess.js`,
  },
  moduleNameMapper: {
    ".+\\.(css|styl|less|sass|scss)$": `identity-obj-proxy`,
    ".+\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": `<rootDir>/tests/support/__mocks__/file-mock.js`,
  },
  testPathIgnorePatterns: [`node_modules`, `\\.cache`, `<rootDir>.*/public`],
  transformIgnorePatterns: [`/node_modules/(?!${modulesToBeIgnored})`],
  globals: {
    __PATH_PREFIX__: ``,
  },
  testURL: `http://localhost`,
  // The setupFiles array lets you list files that will be included before all tests are run
  setupFiles: [`<rootDir>/loadershim.js`, `<rootDir>/tests/support/env-variables.js`],
  collectCoverage: true,
  coveragePathIgnorePatterns: ["/node_modules/", "/public/", "/.cache/"],
  coverageReporters: ["json", "lcov", "text", "text-summary"],
  collectCoverageFrom: ["src/**/*.{js,jsx,ts,tsx}"],
  setupFilesAfterEnv: ["<rootDir>/setup-test-env.js"],
}