vitest-dev/vitest · error · Error

Task instance was not found for

Error message

Task instance was not found for ${runnerTask.type} "${runnerTask.name}"

What it means

Internal invariant in `getReportedTask`: a `RunnerTask` handed to the reporter layer must previously have been registered in `vitest.state.reportedTasksMap` via `storeTask`. A lookup miss means the task reached a reporter/callback without being stored first — a Vitest-internal state desync, not a user configuration problem.

Solutions

Align all `@vitest/*` packages to the same version (`pnpm update -r @vitest/*@vitest/*`).
Disable custom reporters/plugins one by one to isolate which one touches the task lifecycle.
If it reproduces with stock Vitest, file an issue with the task `type`, `name`, and a minimal reproduction.

Defensive patterns

Strategy: try-catch

Try / catch

// In a custom reporter: guard task lookups so a missing reported entity doesn't kill the run.
function safeReportedTask(project, runnerTask) {
  try {
    return project.vitest.state.getReportedEntity(runnerTask)
  } catch {
    return null
  }
}

Prevention

Keep all `@vitest/*` packages on the same released version.
Prefer the public reporter event payloads over reaching into `vitest.state` for raw runner tasks.
If you build a custom reporter, register every task through the documented lifecycle before reading it.

When it happens

Trigger: A reporter or plugin iterating runner tasks receives a `RunnerTask` whose type/name was never passed through `storeTask`; typically arises from custom reporters/hooks that bypass the normal task lifecycle, or from a version mismatch between `vitest` and `@vitest/runner`/reporter packages.

Common situations: Third-party reporter plugins reading raw runner tasks; concurrent/sharded runs hitting a race; mixed `@vitest/*` package versions after a partial upgrade.

Related errors

AI-assisted analysis of vitest-dev/vitest@1fa9837ec2 (2026-08-11). Data as JSON: /api/errors/8758b46771599e50. Report an issue: GitHub.

Appendix: source

Thrown at packages/vitest/src/node/reporters/reported-tasks.ts:779

   */
  readonly workerId: number
}

function storeTask(
  project: TestProject,
  runnerTask: RunnerTask,
  reportedTask: TestCase | TestSuite | TestModule,
): void {
  project.vitest.state.reportedTasksMap.set(runnerTask, reportedTask)
}

function getReportedTask(
  project: TestProject,
  runnerTask: RunnerTask,
): TestCase | TestSuite | TestModule {
  const reportedTask = project.vitest.state.getReportedEntity(runnerTask)
  if (!reportedTask) {
    throw new Error(
      `Task instance was not found for ${runnerTask.type} "${runnerTask.name}"`,
    )
  }
  return reportedTask
}

function getSuiteState(task: RunnerTestSuite | RunnerTestFile): TestSuiteState {
  const mode = task.mode
  const state = task.result?.state
  if (mode === 'skip' || mode === 'todo' || state === 'skip' || state === 'todo') {
    return 'skipped'
  }
  if (state == null || state === 'run' || state === 'only') {
    return 'pending'
  }
  if (state === 'fail') {
    return 'failed'
  }

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