nock

Postconditions — what we check

• nock · unmatched-request-throws

  error
  WhenAn HTTP request is made that does not match any defined interceptor and nock.disableNetConnect() has been called
  ThrowsNetConnectNotAllowedError (error.code === 'ENETUNREACH')
  Required handlingTest assertions MUST account for this error. The most common cause is a URL path, method, query parameter, header, or body mismatch between the real request and the mock definition. Fix the mock to match the actual request, or allow the specific host with nock.enableNetConnect(host).
  costmediumin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[1][2]
• disableNetConnect · real-requests-blocked

  info
  Whencalled without arguments
  Returnsundefined; all subsequent unmatched HTTP requests will throw
  Required handlingNo action required — use the returned value as needed.
  costmediumin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[1]
• cleanAll · all-interceptors-removed

  info
  Whencalled at any point
  Returnsundefined; all pending interceptors are cleared
  Required handlingNo action required — use the returned value as needed.
  costmediumin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[3]
• restore · interception-deactivated

  info
  Whencalled after interception is no longer needed
  Returnsundefined; http module is restored to its original state
  Required handlingNo action required — use the returned value as needed.
  costmediumin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[4]
• isDone · returns-false-for-unused-mocks

  warning
  Whenone or more interceptors on the scope have not been matched by any request
  Returnsfalse
  Required handlingTests SHOULD assert scope.isDone() after the code under test runs. A false return indicates the code did not make the expected request, the mock URL/method/body does not match the real request, or there is a bug in the test logic.
  costmediumin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[5][6]
• isDone · returns-true-when-all-consumed

  info
  Whenall interceptors on the scope have been matched at least once
  Returnstrue
  Required handlingNo action required — use the returned value as needed.
  costmediumin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[5]
• load · load-file-not-found

  error
  WhenThe path argument does not point to an existing file, or the process lacks read permission for the file
  ThrowsError with code ENOENT from fs.readFileSync — "no such file or directory, open '<path>'"
  Required handlingWrap nock.load() in a try-catch. A missing fixture file means all interceptors are absent and all HTTP calls in the test will fail or hit the real network. Test setup MUST validate the fixture path exists before calling load().
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[7][8]
• load · load-invalid-json

  error
  WhenThe fixture file exists but contains invalid JSON (e.g. truncated recording, manual edit error, encoding issue)
  ThrowsSyntaxError from JSON.parse — "Unexpected token ... in JSON at position N"
  Required handlingValidate fixture files are well-formed JSON before committing them. A SyntaxError from nock.load() crashes the entire test suite setup (beforeAll/beforeEach fails), causing all tests in the suite to error rather than fail, making the root cause harder to diagnose.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[7]
• loadDefs · loaddefs-file-not-found

  error
  WhenThe path argument does not point to an existing file
  ThrowsError with code ENOENT from fs.readFileSync
  Required handlingSame as nock.load() — wrap in try-catch. Missing fixture means all definitions are absent. Callers that transform definitions before passing to nock.define() must guard against this error in the transformation pipeline.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[7]
• Scope.done · scope-done-unused-mocks-throw

  error
  WhenOne or more interceptors on the scope have not been matched by a real HTTP request when scope.done() is called
  ThrowsAssertionError: "Mocks not yet satisfied:\n<method> <url>" — lists each pending mock
  Required handlingCall scope.done() only after the code under test has had the opportunity to make all expected HTTP calls. If done() throws, the test has a logic error: either the code under test did not make the expected request, or the mock URL/method/body does not match the actual request. Do not suppress the AssertionError — it is an intentional test signal.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[5]
• Scope.done · scope-done-swallowed-in-async-callback

  warning
  Whenscope.done() is called inside an async callback (setTimeout, promise .then, or event handler) without the test framework being aware of the async assertion
  Required handlingAlways call scope.done() synchronously at the end of the test body, or ensure the test framework is awaiting async assertions (use expect.assertions(n) in Jest, or return the promise from the test function).
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilitysilent
  Sources[5]
• back · back-fixtures-not-set

  error
  Whennock.back.fixtures has not been set to a directory path before calling nock.back()
  ThrowsError: "Back requires nock.back.fixtures to be set\n\tnock.back.fixtures = '/path/to/fixtures/'"
  Required handlingSet nock.back.fixtures = path.join(__dirname, 'fixtures') in a top-level beforeAll hook before any test that uses nock.back(). Missing this causes an immediate throw (not a rejected Promise) — the error surfaces synchronously during the call.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[9]
• back · back-unknown-mode

  error
  Whennock.back.setMode() is called with a string that is not one of 'wild', 'dryrun', 'record', 'update', or 'lockdown'
  ThrowsError — "Unknown mode: <value>"
  Required handlingUse only the five documented BackMode values. The mode is typically set from an environment variable (process.env.NOCK_BACK_MODE). Validate the env var value against the allowed set before passing to setMode().
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[9]

Sources

Every postcondition cites at least one of these. Numbered to match the footnotes above.

1. [1]github.com/nock/nockhttps://github.com/nock/nock#disabling-real-http-requests
2. [2]github.com/nock/nockhttps://github.com/nock/nock/issues/884
3. [3]github.com/nock/nockhttps://github.com/nock/nock#cleanall
4. [4]github.com/nock/nockhttps://github.com/nock/nock#restoring-http-intercepting
5. [5]github.com/nock/nockhttps://github.com/nock/nock#asserting-expectations-after-execution
6. [6]snyk.io/advisor/npm-packagehttps://snyk.io/advisor/npm-package/nock/functions/nock.isDone
7. [7]github.com/nock/nockhttps://github.com/nock/nock#saving-and-loading-interceptors
8. [8]nodejs.org/api/fs.htmlhttps://nodejs.org/api/fs.html#fsreadfilesyncpath-options
9. [9]github.com/nock/nockhttps://github.com/nock/nock#nock-back
10. [10]github.com/nock/nockhttps://github.com/nock/nock/issues/2077