Function handler

packages/vitest/src/node/plugins/runnerTransform.ts:18–76

(config)

    config: {
      order: 'post',
      handler(config) {
        testConfig = config.test || {}

        config.environments ??= {}

        const names = new Set(Object.keys(config.environments))
        names.add('client')
        names.add('ssr')

        const pool = config.test?.pool
        if (pool === 'vmForks' || pool === 'vmThreads') {
          names.add('__vitest_vm__')
        }

        let moduleDirectories = testConfig.deps?.moduleDirectories || []

        const envModuleDirectories
          = process.env.VITEST_MODULE_DIRECTORIES
            || process.env.npm_config_VITEST_MODULE_DIRECTORIES

        if (envModuleDirectories) {
          moduleDirectories.push(...envModuleDirectories.split(','))
        }

        moduleDirectories = moduleDirectories.map(
          (dir) => {
            if (dir[0] !== '/') {
              dir = `/${dir}`
            }
            if (!dir.endsWith('/')) {
              dir += '/'
            }
            return normalize(dir)
          },
        )
        if (!moduleDirectories.includes('/node_modules/')) {
          moduleDirectories.push('/node_modules/')
        }

        testConfig.deps ??= {}
        testConfig.deps.moduleDirectories = moduleDirectories

        for (const name of names) {
          config.environments[name] ??= {}

          const environment = config.environments[name]
          environment.dev ??= {}
          // vm tests run using the native import mechanism
          if (name === '__vitest_vm__') {
            environment.dev.moduleRunnerTransform = false
            environment.consumer = 'client'
          }
          else {
            environment.dev.moduleRunnerTransform = true
          }
          environment.dev.preTransformRequests = false
          environment.keepProcessEnv = true
        }