vitest-dev/vitest · error · TypeError

Expected config.test.coverage.thresholds to be an object

Error message

Expected config.test.coverage.thresholds to be an object

What it means

resolveThresholds (coverage.ts:862) asserts that config.test.coverage.thresholds is an object before reading its keys. Anything else (boolean, array, number, undefined when autoUpdate walks the config file) throws a TypeError.

Source

Thrown at packages/vitest/src/node/coverage.ts:862

      'functions' in thresholds && typeof thresholds.functions === 'number'
        ? thresholds.functions
        : undefined,
    statements:
      'statements' in thresholds && typeof thresholds.statements === 'number'
        ? thresholds.statements
        : undefined,
  }
}

function assertConfigurationModule(config: unknown): asserts config is {
  test: {
    coverage: { thresholds: NonNullable<CoverageOptions['thresholds']> }
  }
} {
  try {
    // @ts-expect-error -- Intentional unsafe null pointer check as wrapped in try-catch
    if (typeof config.test.coverage.thresholds !== 'object') {
      throw new TypeError(
        'Expected config.test.coverage.thresholds to be an object',
      )
    }
  }
  catch (error) {
    const message = error instanceof Error ? error.message : String(error)
    throw new Error(
      `Unable to parse thresholds from configuration file: ${message}`,
    )
  }
}

function resolveConfig(configModule: any) {
  const mod = configModule.exports.default

  try {
    // Check for "export default { test: {...} }"
    if (mod.$type === 'object') {

View on GitHub (pinned to d568f8ce37)

Solutions

1. Set coverage.thresholds to an object, e.g. { lines: 80, functions: 80, branches: 75, statements: 80 }.
2. Remove the thresholds key entirely if you don't enforce thresholds.
3. Re-run after fixing; the message tells you exactly what failed.

Example fix

// before
test: { coverage: { thresholds: true } }

// after
test: { coverage: { thresholds: { lines: 80, functions: 80 } } }

const t = config.test?.coverage?.thresholds
if (t != null && (typeof t !== 'object' || Array.isArray(t))) {
  throw new TypeError('coverage.thresholds must be an object')
}

function isThresholdsObject(t: unknown): t is Record<string, number> {
  return t != null && typeof t === 'object' && !Array.isArray(t)
}

When it happens

Trigger: Config file (or magicast-parsed module) has coverage.thresholds set to a non-object value such as true, null, or an array, and vitest tries to read/update thresholds from it.

Common situations: Setting thresholds: true as a shortcut; copying partial config from docs; autoUpdate walking a misshapen config.

Related errors

• Missing configurationFile. The "coverage.thresholds.autoUpda
• Unable to parse thresholds from configuration file: ${messag
• ${error instanceof Error ? error.message : String(error)}
• Failed to update coverage thresholds. Configuration file is
• Environment "${name}" is not a valid environment. Path "${pa

AI-assisted analysis of vitest-dev/vitest@d568f8ce37 (2026-08-03). Data as JSON: /data/errors/f57d458d6aa74c9e.json. Report an issue: GitHub.