Node.js v24.2.0 documentation
- Node.js v24.2.0
- Other versions
- Options
Table of contents
- About this documentation
- Usage and example
- Assert
- Strict assertion mode
- Legacy assertion mode
- Class: assert.AssertionError
- Class:
assert.CallTracker assert(value[, message])assert.deepEqual(actual, expected[, message])assert.deepStrictEqual(actual, expected[, message])assert.doesNotMatch(string, regexp[, message])assert.doesNotReject(asyncFn[, error][, message])assert.doesNotThrow(fn[, error][, message])assert.equal(actual, expected[, message])assert.fail([message])assert.fail(actual, expected[, message[, operator[, stackStartFn]]])assert.ifError(value)assert.match(string, regexp[, message])assert.notDeepEqual(actual, expected[, message])assert.notDeepStrictEqual(actual, expected[, message])assert.notEqual(actual, expected[, message])assert.notStrictEqual(actual, expected[, message])assert.ok(value[, message])assert.rejects(asyncFn[, error][, message])assert.strictEqual(actual, expected[, message])assert.throws(fn[, error][, message])assert.partialDeepStrictEqual(actual, expected[, message])
- Asynchronous context tracking
- Introduction
- Class:
AsyncLocalStoragenew AsyncLocalStorage([options])- Static method:
AsyncLocalStorage.bind(fn) - Static method:
AsyncLocalStorage.snapshot() asyncLocalStorage.disable()asyncLocalStorage.getStore()asyncLocalStorage.enterWith(store)asyncLocalStorage.nameasyncLocalStorage.run(store, callback[, ...args])asyncLocalStorage.exit(callback[, ...args])- Usage with
async/await - Troubleshooting: Context loss
- Class:
AsyncResourcenew AsyncResource(type[, options])- Static method:
AsyncResource.bind(fn[, type[, thisArg]]) asyncResource.bind(fn[, thisArg])asyncResource.runInAsyncScope(fn[, thisArg, ...args])asyncResource.emitDestroy()asyncResource.asyncId()asyncResource.triggerAsyncId()- Using
AsyncResourcefor aWorkerthread pool - Integrating
AsyncResourcewithEventEmitter
- Async hooks
- Terminology
- Overview
async_hooks.createHook(callbacks)- Class:
AsyncHook - Promise execution tracking
- JavaScript embedder API
- Class:
AsyncLocalStorage
- Buffer
- Buffers and character encodings
- Buffers and TypedArrays
- Buffers and iteration
- Class:
Blob - Class:
Buffer- Static method:
Buffer.alloc(size[, fill[, encoding]]) - Static method:
Buffer.allocUnsafe(size) - Static method:
Buffer.allocUnsafeSlow(size) - Static method:
Buffer.byteLength(string[, encoding]) - Static method:
Buffer.compare(buf1, buf2) - Static method:
Buffer.concat(list[, totalLength]) - Static method:
Buffer.copyBytesFrom(view[, offset[, length]]) - Static method:
Buffer.from(array) - Static method:
Buffer.from(arrayBuffer[, byteOffset[, length]]) - Static method:
Buffer.from(buffer) - Static method:
Buffer.from(object[, offsetOrEncoding[, length]]) - Static method:
Buffer.from(string[, encoding]) - Static method:
Buffer.isBuffer(obj) - Static method:
Buffer.isEncoding(encoding) - Class property:
Buffer.poolSize buf[index]buf.bufferbuf.byteOffsetbuf.compare(target[, targetStart[, targetEnd[, sourceStart[, sourceEnd]]]])buf.copy(target[, targetStart[, sourceStart[, sourceEnd]]])buf.entries()buf.equals(otherBuffer)buf.fill(value[, offset[, end]][, encoding])buf.includes(value[, byteOffset][, encoding])buf.indexOf(value[, byteOffset][, encoding])buf.keys()buf.lastIndexOf(value[, byteOffset][, encoding])buf.lengthbuf.parentbuf.readBigInt64BE([offset])buf.readBigInt64LE([offset])buf.readBigUInt64BE([offset])buf.readBigUInt64LE([offset])buf.readDoubleBE([offset])buf.readDoubleLE([offset])buf.readFloatBE([offset])buf.readFloatLE([offset])buf.readInt8([offset])buf.readInt16BE([offset])buf.readInt16LE([offset])buf.readInt32BE([offset])buf.readInt32LE([offset])buf.readIntBE(offset, byteLength)buf.readIntLE(offset, byteLength)buf.readUInt8([offset])buf.readUInt16BE([offset])buf.readUInt16LE([offset])buf.readUInt32BE([offset])buf.readUInt32LE([offset])buf.readUIntBE(offset, byteLength)buf.readUIntLE(offset, byteLength)buf.subarray([start[, end]])buf.slice([start[, end]])buf.swap16()buf.swap32()buf.swap64()buf.toJSON()buf.toString([encoding[, start[, end]]])buf.values()buf.write(string[, offset[, length]][, encoding])buf.writeBigInt64BE(value[, offset])buf.writeBigInt64LE(value[, offset])buf.writeBigUInt64BE(value[, offset])buf.writeBigUInt64LE(value[, offset])buf.writeDoubleBE(value[, offset])buf.writeDoubleLE(value[, offset])buf.writeFloatBE(value[, offset])buf.writeFloatLE(value[, offset])buf.writeInt8(value[, offset])buf.writeInt16BE(value[, offset])buf.writeInt16LE(value[, offset])buf.writeInt32BE(value[, offset])buf.writeInt32LE(value[, offset])buf.writeIntBE(value, offset, byteLength)buf.writeIntLE(value, offset, byteLength)buf.writeUInt8(value[, offset])buf.writeUInt16BE(value[, offset])buf.writeUInt16LE(value[, offset])buf.writeUInt32BE(value[, offset])buf.writeUInt32LE(value[, offset])buf.writeUIntBE(value, offset, byteLength)buf.writeUIntLE(value, offset, byteLength)new Buffer(array)new Buffer(arrayBuffer[, byteOffset[, length]])new Buffer(buffer)new Buffer(size)new Buffer(string[, encoding])
- Static method:
- Class:
File node:buffermodule APIsBuffer.from(),Buffer.alloc(), andBuffer.allocUnsafe()
- C++ addons
- Node-API
- Implications of ABI stability
- Building
- Usage
- Node-API version matrix
- Environment life cycle APIs
- Basic Node-API data types
- Error handling
- Object lifetime management
- Module registration
- Working with JavaScript values
- Enum types
- Object creation functions
napi_create_arraynapi_create_array_with_lengthnapi_create_arraybuffernapi_create_buffernapi_create_buffer_copynapi_create_datenapi_create_externalnapi_create_external_arraybuffernapi_create_external_buffernapi_create_objectnapi_create_symbolnode_api_symbol_fornapi_create_typedarraynode_api_create_buffer_from_arraybuffernapi_create_dataview
- Functions to convert from C types to Node-API
napi_create_int32napi_create_uint32napi_create_int64napi_create_doublenapi_create_bigint_int64napi_create_bigint_uint64napi_create_bigint_wordsnapi_create_string_latin1node_api_create_external_string_latin1napi_create_string_utf16node_api_create_external_string_utf16napi_create_string_utf8
- Functions to create optimized property keys
- Functions to convert from Node-API to C types
napi_get_array_lengthnapi_get_arraybuffer_infonapi_get_buffer_infonapi_get_prototypenapi_get_typedarray_infonapi_get_dataview_infonapi_get_date_valuenapi_get_value_boolnapi_get_value_doublenapi_get_value_bigint_int64napi_get_value_bigint_uint64napi_get_value_bigint_wordsnapi_get_value_externalnapi_get_value_int32napi_get_value_int64napi_get_value_string_latin1napi_get_value_string_utf8napi_get_value_string_utf16napi_get_value_uint32
- Functions to get global instances
- Working with JavaScript values and abstract operations
- Working with JavaScript properties
- Structures
- Functions
napi_get_property_namesnapi_get_all_property_namesnapi_set_propertynapi_get_propertynapi_has_propertynapi_delete_propertynapi_has_own_propertynapi_set_named_propertynapi_get_named_propertynapi_has_named_propertynapi_set_elementnapi_get_elementnapi_has_elementnapi_delete_elementnapi_define_propertiesnapi_object_freezenapi_object_seal
- Working with JavaScript functions
- Object wrap
- Simple asynchronous operations
- Custom asynchronous operations
- Version management
- Memory management
- Promises
- Script execution
- libuv event loop
- Asynchronous thread-safe function calls
- Calling a thread-safe function
- Reference counting of thread-safe functions
- Deciding whether to keep the process running
napi_create_threadsafe_functionnapi_get_threadsafe_function_contextnapi_call_threadsafe_functionnapi_acquire_threadsafe_functionnapi_release_threadsafe_functionnapi_ref_threadsafe_functionnapi_unref_threadsafe_function
- Miscellaneous utilities
- C++ embedder API
- Child process
- Asynchronous process creation
- Synchronous process creation
- Class:
ChildProcess- Event:
'close' - Event:
'disconnect' - Event:
'error' - Event:
'exit' - Event:
'message' - Event:
'spawn' subprocess.channelsubprocess.connectedsubprocess.disconnect()subprocess.exitCodesubprocess.kill([signal])subprocess[Symbol.dispose]()subprocess.killedsubprocess.pidsubprocess.ref()subprocess.send(message[, sendHandle[, options]][, callback])subprocess.signalCodesubprocess.spawnargssubprocess.spawnfilesubprocess.stderrsubprocess.stdinsubprocess.stdiosubprocess.stdoutsubprocess.unref()
- Event:
maxBufferand Unicode- Shell requirements
- Default Windows shell
- Advanced serialization
- Cluster
- How it works
- Class:
Worker - Event:
'disconnect' - Event:
'exit' - Event:
'fork' - Event:
'listening' - Event:
'message' - Event:
'online' - Event:
'setup' cluster.disconnect([callback])cluster.fork([env])cluster.isMastercluster.isPrimarycluster.isWorkercluster.schedulingPolicycluster.settingscluster.setupMaster([settings])cluster.setupPrimary([settings])cluster.workercluster.workers
- Command-line API
- Synopsis
- Program entry point
- Options
-----abort-on-uncaught-exception--allow-addons--allow-child-process--allow-fs-read--allow-fs-write--allow-wasi--allow-worker--build-snapshot--build-snapshot-config-c,--check--completion-bash-C condition,--conditions=condition--cpu-prof--cpu-prof-dir--cpu-prof-interval--cpu-prof-name--diagnostic-dir=directory--disable-proto=mode--disable-sigusr1--disable-warning=code-or-type--disable-wasm-trap-handler--disallow-code-generation-from-strings--dns-result-order=order--enable-fips--enable-network-family-autoselection--enable-source-maps--entry-url--env-file-if-exists=config--env-file=config-e,--eval "script"--experimental-addon-modules--experimental-config-file=config--experimental-default-config-file--experimental-eventsource--experimental-import-meta-resolve--experimental-loader=module--experimental-network-inspection--experimental-print-required-tla--experimental-require-module--experimental-sea-config--experimental-shadow-realm--experimental-test-coverage--experimental-test-module-mocks--experimental-transform-types--experimental-vm-modules--experimental-wasi-unstable-preview1--experimental-wasm-modules--experimental-webstorage--experimental-worker-inspection--expose-gc--force-context-aware--force-fips--force-node-api-uncaught-exceptions-policy--frozen-intrinsics--heap-prof--heap-prof-dir--heap-prof-interval--heap-prof-name--heapsnapshot-near-heap-limit=max_count--heapsnapshot-signal=signal-h,--help--icu-data-dir=file--import=module--input-type=type--insecure-http-parser--inspect-brk[=[host:]port]--inspect-port=[host:]port--inspect-publish-uid=stderr,http--inspect-wait[=[host:]port]--inspect[=[host:]port]-i,--interactive--jitless--localstorage-file=file--max-http-header-size=size--napi-modules--network-family-autoselection-attempt-timeout--no-addons--no-async-context-frame--no-deprecation--no-experimental-detect-module--no-experimental-global-navigator--no-experimental-repl-await--no-experimental-require-module--no-experimental-sqlite--no-experimental-strip-types--no-experimental-websocket--no-extra-info-on-fatal-exception--no-force-async-hooks-checks--no-global-search-paths--no-network-family-autoselection--no-warnings--node-memory-debug--openssl-config=file--openssl-legacy-provider--openssl-shared-config--pending-deprecation--permission--preserve-symlinks--preserve-symlinks-main-p,--print "script"--prof--prof-process--redirect-warnings=file--report-compact--report-dir=directory,report-directory=directory--report-exclude-env--report-exclude-network--report-filename=filename--report-on-fatalerror--report-on-signal--report-signal=signal--report-uncaught-exception-r,--require module--run--secure-heap-min=n--secure-heap=n--snapshot-blob=path--test--test-concurrency--test-coverage-branches=threshold--test-coverage-exclude--test-coverage-functions=threshold--test-coverage-include--test-coverage-lines=threshold--test-force-exit--test-global-setup=module--test-isolation=mode--test-name-pattern--test-only--test-reporter--test-reporter-destination--test-shard--test-skip-pattern--test-timeout--test-update-snapshots--throw-deprecation