MockErrors

undici raises a dedicated error when a mocked request cannot be matched against any registered interceptor. The mock error classes are exposed through the mockErrors namespace of the package:

import { mockErrors } from 'undici'

if (err instanceof mockErrors.MockNotMatchedError) {
  // handle an unmatched mocked request
}

Like every other undici error, the classes in this namespace extend UndiciError and carry a stable code string, so failures can be distinguished programmatically without relying on the error message.

class MockNotMatchedError extends UndiciError

Thrown when a request issued against a MockAgent does not match any of the registered mock dispatches and the agent is configured to disable net connect.

new MockNotMatchedError(message?): void

Creates a new MockNotMatchedError. When message is omitted, a default message describing the unmatched request is used.

import { mockErrors } from 'undici'

try {
  // ... perform a request that no mock matches ...
} catch (err) {
  if (err.code === 'UND_MOCK_ERR_MOCK_NOT_MATCHED') {
    console.error('No registered mock matched the request')
  }
}