# Node.js Core Test Common Modules
This directory contains modules used to test the Node.js implementation.
## Table of Contents
* [Common module API ](#common-module-api )
* [WPT module ](#wpt-module )
## Common Module API
The `common` module is used by tests for consistency across repeated
tasks.
### allowGlobals(...whitelist)
* `whitelist` [<Array> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array ) Array of Globals
* return [<Array> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array )
Takes `whitelist` and concats that with predefined `knownGlobals` .
### arrayStream
A stream to push an array into a REPL
### busyLoop(time)
* `time` [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type )
Blocks for `time` amount of time.
### canCreateSymLink
API to indicate whether the current running process can create
symlinks. On Windows, this returns false if the process running
doesn't have privileges to create symlinks (specifically
[SeCreateSymbolicLinkPrivilege ](https://msdn.microsoft.com/en-us/library/windows/desktop/bb530716(v=vs.85 ).aspx)).
On non-Windows platforms, this currently returns true.
### crashOnUnhandledRejection()
Installs a `process.on('unhandledRejection')` handler that crashes the process
after a tick. This is useful for tests that use Promises and need to make sure
no unexpected rejections occur, because currently they result in silent
failures.
### ddCommand(filename, kilobytes)
* return [<Object> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object )
Platform normalizes the `dd` command
### enoughTestMem
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Check if there is more than 1gb of total memory.
### expectsError(settings)
* `settings` [<Object> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object )
with the following optional properties:
* `code` [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
expected error must have this value for its `code` property
* `type` [<Function> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function )
expected error must be an instance of `type`
* `message` [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
or [<RegExp> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp )
if a string is provided for `message` , expected error must have it for its
`message` property; if a regular expression is provided for `message` , the
regular expression must match the `message` property of the expected error
* return function suitable for use as a validation function passed as the second
argument to `assert.throws()`
The expected error should be [subclassed by the `internal/errors` module ](https://github.com/nodejs/node/blob/master/doc/guides/using-internal-errors.md#api ).
### expectWarning(name, expected)
* `name` [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
* `expected` [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type ) | [<Array> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array )
Tests whether `name` and `expected` are part of a raised warning.
### fileExists(pathname)
* pathname [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks if `pathname` exists
### fixturesDir
* return [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
Path to the 'fixtures' directory.
### getArrayBufferViews(buf)
* `buf` [<Buffer> ](https://nodejs.org/api/buffer.html#buffer_class_buffer )
* return [<ArrayBufferView[]> ](https://developer.mozilla.org/en-US/docs/Web/API/ArrayBufferView )
Returns an instance of all possible `ArrayBufferView` s of the provided Buffer.
### globalCheck
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Turn this off if the test should not check for global leaks.
### hasCrypto
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks for 'openssl'.
### hasFipsCrypto
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks `hasCrypto` and `crypto` with fips.
### hasIntl
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks if [internationalization] is supported.
### hasSmallICU
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks `hasIntl` and `small-icu` is supported.
### hasIPv6
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks whether `IPv6` is supported on this platform.
### hasMultiLocalhost
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks if there are multiple localhosts available.
### hijackStderr(listener)
* `listener` [< Function>][MDN-Function]: a listener with a single parameter called `data` .
Eavesdrop to `process.stderr.write` calls. Once `process.stderr.write` is
called, `listener` will also be called and the `data` of `write` function will
be passed to `listener` . What's more, `process.stderr.writeTimes` is a count of
the number of calls.
### hijackStdout(listener)
* `listener` [< Function>][MDN-Function]: a listener with a single parameter called `data` .
Eavesdrop to `process.stdout.write` calls. Once `process.stdout.write` is
called, `listener` will also be called and the `data` of `write` function will
be passed to `listener` . What's more, `process.stdout.writeTimes` is a count of
the number of calls.
### inFreeBSDJail
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks whether free BSD Jail is true or false.
### isAix
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for Advanced Interactive eXecutive (AIX).
### isAlive(pid)
* `pid` [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type )
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Attempts to 'kill' `pid`
### isFreeBSD
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for Free BSD.
### isLinux
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for Linux.
### isLinuxPPCBE
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for Linux on PowerPC.
### isOSX
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for macOS.
### isSunOS
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for SunOS.
### isWindows
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for Windows.
### isWOW64
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Platform check for Windows 32-bit on Windows 64-bit.
### leakedGlobals
* return [<Array> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array )
Checks whether any globals are not on the `knownGlobals` list.
### localhostIPv4
* return [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
Gets IP of localhost
### localIPv6Hosts
* return [<Array> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array )
Array of IPV6 hosts.
### mustCall([fn][, exact])
* `fn` [<Function> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function ) default = `common.noop`
* `exact` [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type ) default = 1
* return [<Function> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function )
Returns a function that calls `fn` . If the returned function has not been called
exactly `expected` number of times when the test is complete, then the test will
fail.
If `fn` is not provided, `common.noop` will be used.
### mustCallAtLeast([fn][, minimum])
* `fn` [<Function> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function ) default = `common.noop`
* `minimum` [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type ) default = 1
* return [<Function> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function )
Returns a function that calls `fn` . If the returned function has not been called
at least `minimum` number of times when the test is complete, then the test will
fail.
If `fn` is not provided, `common.noop` will be used.
### mustNotCall([msg])
* `msg` [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type ) default = 'function should not have been called'
* return [<Function> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function )
Returns a function that triggers an `AssertionError` if it is invoked. `msg` is used as the error message for the `AssertionError` .
### nodeProcessAborted(exitCode, signal)
* `exitCode` [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type )
* `signal` [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Returns `true` if the exit code `exitCode` and/or signal name `signal` represent the exit code and/or signal name of a node process that aborted, `false` otherwise.
### noop
A non-op `Function` that can be used for a variety of scenarios.
For instance,
<!-- eslint - disable strict, no - undef -->
```js
const common = require('../common');
someAsyncAPI('foo', common.mustCall(common.noop));
```
### opensslCli
* return [<Boolean> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type )
Checks whether 'opensslCli' is supported.
### platformTimeout(ms)
* `ms` [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type )
* return [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type )
Platform normalizes timeout.
### PIPE
* return [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
Path to the test sock.
### PORT
* return [<Number> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type ) default = `12346`
Port tests are running on.
### refreshTmpDir
* return [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
Deletes the 'tmp' dir and recreates it
### restoreStderr()
Restore the original `process.stderr.write` .
### restoreStdout()
Restore the original `process.stdout.write` .
### rootDir
* return [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
Path to the 'root' directory. either `/` or `c:\\` (windows)
### skip(msg)
* `msg` [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
Logs '1..0 # Skipped: ' + `msg`
### spawnPwd(options)
* `options` [<Object> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object )
* return [<Object> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object )
Platform normalizes the `pwd` command.
### spawnSyncPwd(options)
* `options` [<Object> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object )
* return [<Object> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object )
Synchronous version of `spawnPwd` .
### tmpDir
* return [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
The realpath of the 'tmp' directory.
### tmpDirName
* return [<String> ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type )
Name of the temp directory used by tests.
## WPT Module
The wpt.js module is a port of parts of
[W3C testharness.js ](https://github.com/w3c/testharness.js ) for testing the
Node.js
[WHATWG URL API ](https://nodejs.org/api/url.html#url_the_whatwg_url_api )
implementation with tests from
[W3C Web Platform Tests ](https://github.com/w3c/web-platform-tests ).
[MDN-Function]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Normal_objects_and_functions
[internationalization]: https://github.com/nodejs/node/wiki/Intl