jest.config.mjs

const defaultConfig = {
  coverageDirectory: 'coverage',
  coverageProvider: 'v8',
  coverageReporters: [ 'text', 'lcov' ],
  coverageThreshold: {
    global:{
      branches: 100,
      functions: 100,
      lines: 100,
      statements: 100,
    }
  },
  maxWorkers: '50%',
  watchPathIgnorePatterns: [
    'node_modules'
  ],
  transformIgnorePatterns:[
    'node_modules'
  ]
}

export default{
  projects: [{
    ...defaultConfig,
    testEnvironment: 'node',
    displayName: 'backend',
    collectCoverageFrom:[
      "server/",
      "!server/index.js",
    ],
    transformIgnorePatterns:[
      ...defaultConfig.transformIgnorePatterns,
      'public'
    ],
    testMatch:[
      "**/tests/**/server/**/*.test.js"
    ]
  },
  {
    ...defaultConfig,
    testEnvironment: 'jsdom',
    displayName: 'frontend',
    collectCoverageFrom:[
      "public/"
    ],
    transformIgnorePatterns:[
      ...defaultConfig.transformIgnorePatterns,
      'server'
    ],
    testMatch:[
      "**/tests/**/public/**/*.test.js"
    ]
  }
]
}