# Node.js Core Test Common Modules This directory contains modules used to test the Node.js implementation. ## Table of Contents * [Benchmark module](#benchmark-module) * [Common module API](#common-module-api) * [Countdown module](#countdown-module) * [DNS module](#dns-module) * [Duplex pair helper](#duplex-pair-helper) * [Fixtures module](#fixtures-module) * [Heap dump checker module](#heap-dump-checker-module) * [HTTP2 module](#http2-module) * [Internet module](#internet-module) * [tmpdir module](#tmpdir-module) * [WPT module](#wpt-module) ## Benchmark Module The `benchmark` module is used by tests to run benchmarks. ### runBenchmark(name, args, env) * `name` [<string>] Name of benchmark suite to be run. * `args` [<Array>] Array of environment variable key/value pairs (ex: `n=1`) to be applied via `--set`. * `env` [<Object>] Environment variables to be applied during the run. ## Common Module API The `common` module is used by tests for consistency across repeated tasks. ### allowGlobals(...whitelist) * `whitelist` [<Array>] Array of Globals * return [<Array>] Takes `whitelist` and concats that with predefined `knownGlobals`. ### busyLoop(time) * `time` [<number>] Blocks for `time` amount of time. ### canCreateSymLink() * return [<boolean>] Checks whether the current running process can create symlinks. On Windows, this returns `false` if the process running doesn't have privileges to create symlinks ([SeCreateSymbolicLinkPrivilege](https://msdn.microsoft.com/en-us/library/windows/desktop/bb530716(v=vs.85).aspx)). On non-Windows platforms, this always returns `true`. ### ddCommand(filename, kilobytes) * return [<Object>] Platform normalizes the `dd` command ### disableCrashOnUnhandledRejection() Removes the `process.on('unhandledRejection')` handler that crashes the process after a tick. The handler is useful for tests that use Promises and need to make sure no unexpected rejections occur, because currently they result in silent failures. However, it is useful in some rare cases to disable it, for example if the `unhandledRejection` hook is directly used by the test. ### enoughTestMem * [<boolean>] Indicates if there is more than 1gb of total memory. ### expectsError([fn, ]settings[, exact]) * `fn` [<Function>] a function that should throw. * `settings` [<Object>] that must contain the `code` property plus any of the other following properties (some properties only apply for `AssertionError`): * `code` [<string>] expected error must have this value for its `code` property. * `type` [<Function>] expected error must be an instance of `type` and must be an Error subclass. * `message` [<string>] or [<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. * `name` [<string>] expected error must have this value for its `name` property. * `info` <Object> expected error must have the same `info` property that is deeply equal to this value. * `generatedMessage` [<string>] (`AssertionError` only) expected error must have this value for its `generatedMessage` property. * `actual` <any> (`AssertionError` only) expected error must have this value for its `actual` property. * `expected` <any> (`AssertionError` only) expected error must have this value for its `expected` property. * `operator` <any> (`AssertionError` only) expected error must have this value for its `operator` property. * `exact` [<number>] default = 1 * return [<Function>] If `fn` is provided, it will be passed to `assert.throws` as first argument and `undefined` will be returned. Otherwise a function suitable as callback or for use as a validation function passed as the second argument to `assert.throws()` will be returned. If the returned function has not been called exactly `exact` number of times when the test is complete, then the test will fail. ### expectWarning(name, expected, code) * `name` [<string>] * `expected` [<string>] | [<Array>] * `code` [<string>] Tests whether `name`, `expected`, and `code` are part of a raised warning. If an expected warning does not have a code then `common.noWarnCode` can be used to indicate this. ### getArrayBufferViews(buf) * `buf` [<Buffer>] * return [<ArrayBufferView[]>] Returns an instance of all possible `ArrayBufferView`s of the provided Buffer. ### getBufferSources(buf) * `buf` [<Buffer>] * return [<BufferSource[]>] Returns an instance of all possible `BufferSource`s of the provided Buffer, consisting of all `ArrayBufferView` and an `ArrayBuffer`. ### getCallSite(func) * `func` [<Function>] * return [<string>] Returns the file name and line number for the provided Function. ### getTTYfd() Attempts to get a valid TTY file descriptor. Returns `-1` if it fails. The TTY file descriptor is assumed to be capable of being writable. ### hasCrypto * [<boolean>] Indicates whether OpenSSL is available. ### hasFipsCrypto * [<boolean>] Indicates `hasCrypto` and `crypto` with fips. ### hasIntl * [<boolean>] Indicates if [internationalization] is supported. ### hasSmallICU * [<boolean>] Indicates `hasIntl` and `small-icu` are supported. ### hasIPv6 * [<boolean>] Indicates whether `IPv6` is supported on this platform. ### hasMultiLocalhost * [<boolean>] Indicates if there are multiple localhosts available. ### hijackStderr(listener) * `listener` [<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>]: 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 * [<boolean>] Checks whether free BSD Jail is true or false. ### isAIX * [<boolean>] Platform check for Advanced Interactive eXecutive (AIX). ### isAlive(pid) * `pid` [<number>] * return [<boolean>] Attempts to 'kill' `pid` ### isFreeBSD * [<boolean>] Platform check for Free BSD. ### isLinux * [<boolean>] Platform check for Linux. ### isLinuxPPCBE * [<boolean>] Platform check for Linux on PowerPC. ### isOSX * [<boolean>] Platform check for macOS. ### isSunOS * [<boolean>] Platform check for SunOS. ### isWindows * [<boolean>] Platform check for Windows. ### isWOW64 * [<boolean>] Platform check for Windows 32-bit on Windows 64-bit. ### isCPPSymbolsNotMapped * [<boolean>] Platform check for C++ symbols are mapped or not. ### leakedGlobals() * return [<Array>] Indicates whether any globals are not on the `knownGlobals` list. ### localhostIPv4 * [<string>] IP of `localhost`. ### localIPv6Hosts * [<Array>] Array of IPV6 representations for `localhost`. ### mustCall([fn][, exact]) * `fn` [<Function>] default = () => {} * `exact` [<number>] default = 1 * return [<Function>] Returns a function that calls `fn`. If the returned function has not been called exactly `exact` number of times when the test is complete, then the test will fail. If `fn` is not provided, an empty function will be used. ### mustCallAsync([fn][, exact]) * `fn` [<Function>] * `exact` [<number>] default = 1 * return [<Function>] The same as `mustCall()`, except that it is also checked that the Promise returned by the function is fulfilled for each invocation of the function. The return value of the wrapped function is the return value of the original function, if necessary wrapped as a promise. ### mustCallAtLeast([fn][, minimum]) * `fn` [<Function>] default = () => {} * `minimum` [<number>] default = 1 * return [<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, an empty function will be used. ### mustNotCall([msg]) * `msg` [<string>] default = 'function should not have been called' * return [<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>] * `signal` [<string>] * return [<boolean>] 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. ### noWarnCode See `common.expectWarning()` for usage. ### onGC(target, listener) * `target` [<Object>] * `listener` [<Object>] * `ongc` [<Function>] Installs a GC listener for the collection of `target`. This uses `async_hooks` for GC tracking. This means that it enables `async_hooks` tracking, which may affect the test functionality. It also means that between a `global.gc()` call and the listener being invoked a full `setImmediate()` invocation passes. `listener` is an object to make it easier to use a closure; the target object should not be in scope when `listener.ongc()` is created. ### opensslCli * [<boolean>] Indicates whether 'opensslCli' is supported. ### platformTimeout(ms) * `ms` [<number>] * return [<number>] Platform normalizes timeout. ### PIPE * [<string>] Path to the test socket. ### PORT * [<number>] A port number for tests to use if one is needed. ### printSkipMessage(msg) * `msg` [<string>] Logs '1..0 # Skipped: ' + `msg` ### restoreStderr() Restore the original `process.stderr.write`. Used to restore `stderr` to its original state after calling [`common.hijackStdErr()`][]. ### restoreStdout() Restore the original `process.stdout.write`. Used to restore `stdout` to its original state after calling [`common.hijackStdOut()`][]. ### rootDir * [<string>] Path to the 'root' directory. either `/` or `c:\\` (windows) ### runWithInvalidFD(func) * `func` [<Function>] Runs `func` with an invalid file descriptor that is an unsigned integer and can be used to trigger `EBADF` as the first argument. If no such file descriptor could be generated, a skip message will be printed and the `func` will not be run. ### skip(msg) * `msg` [<string>] Logs '1..0 # Skipped: ' + `msg` and exits with exit code `0`. ### skipIfEslintMissing() Skip the rest of the tests in the current file when `ESLint` is not available at `tools/node_modules/eslint` ### skipIfInspectorDisabled() Skip the rest of the tests in the current file when the Inspector was disabled at compile time. ### skipIf32Bits() Skip the rest of the tests in the current file when the Node.js executable was compiled with a pointer size smaller than 64 bits. ### spawnPwd(options) * `options` [<Object>] * return [<Object>] Platform normalizes the `pwd` command. ### spawnSyncPwd(options) * `options` [<Object>] * return [<Object>] Synchronous version of `spawnPwd`. ## ArrayStream Module The `ArrayStream` module provides a simple `Stream` that pushes elements from a given array. ```js const ArrayStream = require('../common/arraystream'); const stream = new ArrayStream(); stream.run(['a', 'b', 'c']); ``` It can be used within tests as a simple mock stream. ## Countdown Module The `Countdown` module provides a simple countdown mechanism for tests that require a particular action to be taken after a given number of completed tasks (for instance, shutting down an HTTP server after a specific number of requests). The Countdown will fail the test if the remainder did not reach 0. ```js const Countdown = require('../common/countdown'); function doSomething() { console.log('.'); } const countdown = new Countdown(2, doSomething); countdown.dec(); countdown.dec(); ``` ### new Countdown(limit, callback) * `limit` {number} * `callback` {function} Creates a new `Countdown` instance. ### Countdown.prototype.dec() Decrements the `Countdown` counter. ### Countdown.prototype.remaining Specifies the remaining number of times `Countdown.prototype.dec()` must be called before the callback is invoked. ## DNS Module The `DNS` module provides utilities related to the `dns` built-in module. ### errorLookupMock(code, syscall) * `code` [<string>] Defaults to `dns.mockedErrorCode`. * `syscall` [<string>] Defaults to `dns.mockedSysCall`. * return [<Function>] A mock for the `lookup` option of `net.connect()` that would result in an error with the `code` and the `syscall` specified. Returns a function that has the same signature as `dns.lookup()`. ### mockedErrorCode The default `code` of errors generated by `errorLookupMock`. ### mockedSysCall The default `syscall` of errors generated by `errorLookupMock`. ### readDomainFromPacket(buffer, offset) * `buffer` [<Buffer>] * `offset` [<number>] * return [<Object>] Reads the domain string from a packet and returns an object containing the number of bytes read and the domain. ### parseDNSPacket(buffer) * `buffer` [<Buffer>] * return [<Object>] Parses a DNS packet. Returns an object with the values of the various flags of the packet depending on the type of packet. ### writeIPv6(ip) * `ip` [<string>] * return [<Buffer>] Reads an IPv6 String and returns a Buffer containing the parts. ### writeDomainName(domain) * `domain` [<string>] * return [<Buffer>] Reads a Domain String and returns a Buffer containing the domain. ### writeDNSPacket(parsed) * `parsed` [<Object>] * return [<Buffer>] Takes in a parsed Object and writes its fields to a DNS packet as a Buffer object. ## Duplex pair helper The `common/duplexpair` module exports a single function `makeDuplexPair`, which returns an object `{ clientSide, serverSide }` where each side is a `Duplex` stream connected to the other side. There is no difference between client or server side beyond their names. ## Fixtures Module The `common/fixtures` module provides convenience methods for working with files in the `test/fixtures` directory. ### fixtures.fixturesDir * [<string>] The absolute path to the `test/fixtures/` directory. ### fixtures.path(...args) * `...args` [<string>] Returns the result of `path.join(fixtures.fixturesDir, ...args)`. ### fixtures.readSync(args[, enc]) * `args` [<string>] | [<Array>] Returns the result of `fs.readFileSync(path.join(fixtures.fixturesDir, ...args), 'enc')`. ### fixtures.readKey(arg[, enc]) * `arg` [<string>] Returns the result of `fs.readFileSync(path.join(fixtures.fixturesDir, 'keys', arg), 'enc')`. ## Heap dump checker module This provides utilities for checking the validity of heap dumps. This requires the usage of `--expose-internals`. ### heap.recordState() Create a heap dump and an embedder graph copy for inspection. The returned object has a `validateSnapshotNodes` function similar to the one listed below. (`heap.validateSnapshotNodes(...)` is a shortcut for `heap.recordState().validateSnapshotNodes(...)`.) ### heap.validateSnapshotNodes(name, expected, options) * `name` [<string>] Look for this string as the name of heap dump nodes. * `expected` [<Array>] A list of objects, possibly with an `children` property that points to expected other adjacent nodes. * `options` [<Array>] * `loose` [<boolean>] Do not expect an exact listing of occurrences of nodes with name `name` in `expected`. Create a heap dump and an embedder graph copy and validate occurrences. ```js validateSnapshotNodes('TLSWRAP', [ { children: [ { name: 'enc_out' }, { name: 'enc_in' }, { name: 'TLSWrap' } ] } ]); ``` ## HTTP/2 Module The http2.js module provides a handful of utilities for creating mock HTTP/2 frames for testing of HTTP/2 endpoints ```js const http2 = require('../common/http2'); ``` ### Class: Frame The `http2.Frame` is a base class that creates a `Buffer` containing a serialized HTTP/2 frame header. ```js // length is a 24-bit unsigned integer // type is an 8-bit unsigned integer identifying the frame type // flags is an 8-bit unsigned integer containing the flag bits // id is the 32-bit stream identifier, if any. const frame = new http2.Frame(length, type, flags, id); // Write the frame data to a socket socket.write(frame.data); ``` The serialized `Buffer` may be retrieved using the `frame.data` property. ### Class: DataFrame extends Frame The `http2.DataFrame` is a subclass of `http2.Frame` that serializes a `DATA` frame. ```js // id is the 32-bit stream identifier // payload is a Buffer containing the DATA payload // padlen is an 8-bit integer giving the number of padding bytes to include // final is a boolean indicating whether the End-of-stream flag should be set, // defaults to false. const frame = new http2.DataFrame(id, payload, padlen, final); socket.write(frame.data); ``` ### Class: HeadersFrame The `http2.HeadersFrame` is a subclass of `http2.Frame` that serializes a `HEADERS` frame. ```js // id is the 32-bit stream identifier // payload is a Buffer containing the HEADERS payload (see either // http2.kFakeRequestHeaders or http2.kFakeResponseHeaders). // padlen is an 8-bit integer giving the number of padding bytes to include // final is a boolean indicating whether the End-of-stream flag should be set, // defaults to false. const frame = new http2.HeadersFrame(id, payload, padlen, final); socket.write(frame.data); ``` ### Class: SettingsFrame The `http2.SettingsFrame` is a subclass of `http2.Frame` that serializes an empty `SETTINGS` frame. ```js // ack is a boolean indicating whether or not to set the ACK flag. const frame = new http2.SettingsFrame(ack); socket.write(frame.data); ``` ### http2.kFakeRequestHeaders Set to a `Buffer` instance that contains a minimal set of serialized HTTP/2 request headers to be used as the payload of a `http2.HeadersFrame`. ```js const frame = new http2.HeadersFrame(1, http2.kFakeRequestHeaders, 0, true); socket.write(frame.data); ``` ### http2.kFakeResponseHeaders Set to a `Buffer` instance that contains a minimal set of serialized HTTP/2 response headers to be used as the payload a `http2.HeadersFrame`. ```js const frame = new http2.HeadersFrame(1, http2.kFakeResponseHeaders, 0, true); socket.write(frame.data); ``` ### http2.kClientMagic Set to a `Buffer` containing the preamble bytes an HTTP/2 client must send upon initial establishment of a connection. ```js socket.write(http2.kClientMagic); ``` ## Internet Module The `common/internet` module provides utilities for working with internet-related tests. ### internet.addresses * [<Object>] * `INET_HOST` [<string>] A generic host that has registered common DNS records, supports both IPv4 and IPv6, and provides basic HTTP/HTTPS services * `INET4_HOST` [<string>] A host that provides IPv4 services * `INET6_HOST` [<string>] A host that provides IPv6 services * `INET4_IP` [<string>] An accessible IPv4 IP, defaults to the Google Public DNS IPv4 address * `INET6_IP` [<string>] An accessible IPv6 IP, defaults to the Google Public DNS IPv6 address * `INVALID_HOST` [<string>] An invalid host that cannot be resolved * `MX_HOST` [<string>] A host with MX records registered * `SRV_HOST` [<string>] A host with SRV records registered * `PTR_HOST` [<string>] A host with PTR records registered * `NAPTR_HOST` [<string>] A host with NAPTR records registered * `SOA_HOST` [<string>] A host with SOA records registered * `CNAME_HOST` [<string>] A host with CNAME records registered * `NS_HOST` [<string>] A host with NS records registered * `TXT_HOST` [<string>] A host with TXT records registered * `DNS4_SERVER` [<string>] An accessible IPv4 DNS server * `DNS6_SERVER` [<string>] An accessible IPv6 DNS server A set of addresses for internet-related tests. All properties are configurable via `NODE_TEST_*` environment variables. For example, to configure `internet.addresses.INET_HOST`, set the environment variable `NODE_TEST_INET_HOST` to a specified host. ## tmpdir Module The `tmpdir` module supports the use of a temporary directory for testing. ### path * [<string>] The realpath of the testing temporary directory. ### refresh() Deletes and recreates the testing temporary directory. ## 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). [<Array>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array [<ArrayBufferView[]>]: https://developer.mozilla.org/en-US/docs/Web/API/ArrayBufferView [<Buffer>]: https://nodejs.org/api/buffer.html#buffer_class_buffer [<Function>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function [<Object>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object [<RegExp>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp [<boolean>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type [<number>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type [<string>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type [`common.hijackStdErr()`]: #hijackstderrlistener [`common.hijackStdOut()`]: #hijackstdoutlistener [internationalization]: https://github.com/nodejs/node/wiki/Intl