vitest-dev/vitest · error · TypeError

Environment ${environment.name} doesn't provide "getVmContex

Error message

Environment ${environment.name} doesn't provide "getVmContext" method. It should return a context created by "vm.createContext" method.

What it means

After calling environment.setupVM(...) in the VM pool (vm.ts:73-77), Vitest expects the returned object to expose a getVmContext() method that yields the vm.Context. If that method is missing, this TypeError is thrown. The environment implemented setupVM but returned an object of the wrong shape.

Source

Thrown at packages/vitest/src/runtime/workers/vm.ts:74

  }

  const vm = await traces.$(
    'vitest.runtime.environment.setup',
    {
      attributes: {
        'vitest.environment': environment.name,
        'vitest.environment.vite_environment': environment.viteEnvironment || environment.name,
      },
    },
    () => environment.setupVM!(ctx.environment.options || ctx.config.environmentOptions || {}),
  )

  state.durations.environment = performance.now() - beforeEnvironmentTime

  process.env.VITEST_VM_POOL = '1'

  if (!vm.getVmContext) {
    throw new TypeError(
      `Environment ${environment.name} doesn't provide "getVmContext" method. It should return a context created by "vm.createContext" method.`,
    )
  }

  const context: Context | null = vm.getVmContext()

  if (!isContext(context)) {
    throw new TypeError(
      `Environment ${environment.name} doesn't provide a valid context. It should be created by "vm.createContext" method.`,
    )
  }

  provideWorkerState(context, state)

  // this is unfortunately needed for our own dependencies
  // we need to find a way to not rely on this by default
  // because browser doesn't provide these globals
  context.process = process

View on GitHub (pinned to d568f8ce37)

Solutions

1. Make setupVM return an object exposing getVmContext: () => vm.createContext(...).
2. Follow the Environment type (getVmContext is part of the VMEnvironment contract) rather than ad-hoc shapes.
3. Add a teardown() method too so the VM context can be cleaned up.

Example fix

// before: returns context directly
setupVM(options) {
  return vm.createContext({})
}

// after: returns object with getVmContext
setupVM(options) {
  const context = vm.createContext({})
  return { getVmContext: () => context }
}

interface VmEnvironmentResult { getVmContext: () => unknown; teardown?: () => void }

function hasGetVmContext(value: unknown): value is VmEnvironmentResult {
  return !!value && typeof (value as any).getVmContext === 'function'
}

When it happens

Trigger: A custom environment whose setupVM returns an object without a getVmContext function — e.g. returns the context directly, or returns { context } instead of { getVmContext: () => context }.

Common situations: Implementing setupVM for the first time and returning the bare context; following an outdated guide; copy-pasting a setup-style return into setupVM.

Related errors

• Environment "${ctx.environment.name}" is not a valid environ
• Environment ${environment.name} doesn't provide a valid cont
• Not called in the browser
• Vitest mocker was not initialized in this environment. vi.${
• Environment "${name}" is not a valid environment. Path "${pa

AI-assisted analysis of vitest-dev/vitest@d568f8ce37 (2026-08-03). Data as JSON: /data/errors/8a0708a659313d60.json. Report an issue: GitHub.