80 KiB
Errors
Applications running in Node.js will generally experience four categories of errors:
- Standard JavaScript errors such as {EvalError}, {SyntaxError}, {RangeError}, {ReferenceError}, {TypeError}, and {URIError}.
- System errors triggered by underlying operating system constraints such as attempting to open a file that does not exist or attempting to send data over a closed socket.
- User-specified errors triggered by application code.
AssertionError
s are a special class of error that can be triggered when Node.js detects an exceptional logic violation that should never occur. These are raised typically by theassert
module.
All JavaScript and System errors raised by Node.js inherit from, or are instances of, the standard JavaScript {Error} class and are guaranteed to provide at least the properties available on that class.
Error Propagation and Interception
Node.js supports several mechanisms for propagating and handling errors that
occur while an application is running. How these errors are reported and
handled depends entirely on the type of Error
and the style of the API that is
called.
All JavaScript errors are handled as exceptions that immediately generate
and throw an error using the standard JavaScript throw
mechanism. These
are handled using the try…catch
construct provided by the
JavaScript language.
// Throws with a ReferenceError because z is not defined.
try {
const m = 1;
const n = m + z;
} catch (err) {
// Handle the error here.
}
Any use of the JavaScript throw
mechanism will raise an exception that
must be handled using try…catch
or the Node.js process will exit
immediately.
With few exceptions, Synchronous APIs (any blocking method that does not
accept a callback
function, such as fs.readFileSync
), will use throw
to report errors.
Errors that occur within Asynchronous APIs may be reported in multiple ways:
- Most asynchronous methods that accept a
callback
function will accept anError
object passed as the first argument to that function. If that first argument is notnull
and is an instance ofError
, then an error occurred that should be handled.
const fs = require('fs');
fs.readFile('a file that does not exist', (err, data) => {
if (err) {
console.error('There was an error reading the file!', err);
return;
}
// Otherwise handle the data
});
-
When an asynchronous method is called on an object that is an
EventEmitter
, errors can be routed to that object's'error'
event.const net = require('net'); const connection = net.connect('localhost'); // Adding an 'error' event handler to a stream: connection.on('error', (err) => { // If the connection is reset by the server, or if it can't // connect at all, or on any sort of error encountered by // the connection, the error will be sent here. console.error(err); }); connection.pipe(process.stdout);
-
A handful of typically asynchronous methods in the Node.js API may still use the
throw
mechanism to raise exceptions that must be handled usingtry…catch
. There is no comprehensive list of such methods; please refer to the documentation of each method to determine the appropriate error handling mechanism required.
The use of the 'error'
event mechanism is most common for stream-based
and event emitter-based APIs, which themselves represent a series of
asynchronous operations over time (as opposed to a single operation that may
pass or fail).
For all EventEmitter
objects, if an 'error'
event handler is not
provided, the error will be thrown, causing the Node.js process to report an
uncaught exception and crash unless either: The domain
module is
used appropriately or a handler has been registered for the
'uncaughtException'
event.
const EventEmitter = require('events');
const ee = new EventEmitter();
setImmediate(() => {
// This will crash the process because no 'error' event
// handler has been added.
ee.emit('error', new Error('This will crash'));
});
Errors generated in this way cannot be intercepted using try…catch
as
they are thrown after the calling code has already exited.
Developers must refer to the documentation for each method to determine exactly how errors raised by those methods are propagated.
Error-first callbacks
Most asynchronous methods exposed by the Node.js core API follow an idiomatic
pattern referred to as an error-first callback. With this pattern, a callback
function is passed to the method as an argument. When the operation either
completes or an error is raised, the callback function is called with the
Error
object (if any) passed as the first argument. If no error was raised,
the first argument will be passed as null
.
const fs = require('fs');
function errorFirstCallback(err, data) {
if (err) {
console.error('There was an error', err);
return;
}
console.log(data);
}
fs.readFile('/some/file/that/does-not-exist', errorFirstCallback);
fs.readFile('/some/file/that/does-exist', errorFirstCallback);
The JavaScript try…catch
mechanism cannot be used to intercept errors
generated by asynchronous APIs. A common mistake for beginners is to try to
use throw
inside an error-first callback:
// THIS WILL NOT WORK:
const fs = require('fs');
try {
fs.readFile('/some/file/that/does-not-exist', (err, data) => {
// Mistaken assumption: throwing here...
if (err) {
throw err;
}
});
} catch (err) {
// This will not catch the throw!
console.error(err);
}
This will not work because the callback function passed to fs.readFile()
is
called asynchronously. By the time the callback has been called, the
surrounding code, including the try…catch
block, will have already exited.
Throwing an error inside the callback can crash the Node.js process in most
cases. If domains are enabled, or a handler has been registered with
process.on('uncaughtException')
, such errors can be intercepted.
Class: Error
A generic JavaScript {Error} object that does not denote any specific
circumstance of why the error occurred. Error
objects capture a "stack trace"
detailing the point in the code at which the Error
was instantiated, and may
provide a text description of the error.
All errors generated by Node.js, including all System and JavaScript errors,
will either be instances of, or inherit from, the Error
class.
new Error(message)
message
{string}
Creates a new Error
object and sets the error.message
property to the
provided text message. If an object is passed as message
, the text message
is generated by calling message.toString()
. The error.stack
property will
represent the point in the code at which new Error()
was called. Stack traces
are dependent on V8's stack trace API. Stack traces extend only to either
(a) the beginning of synchronous code execution, or (b) the number of frames
given by the property Error.stackTraceLimit
, whichever is smaller.
Error.captureStackTrace(targetObject[, constructorOpt])
targetObject
{Object}constructorOpt
{Function}
Creates a .stack
property on targetObject
, which when accessed returns
a string representing the location in the code at which
Error.captureStackTrace()
was called.
const myObject = {};
Error.captureStackTrace(myObject);
myObject.stack; // Similar to `new Error().stack`
The first line of the trace will be prefixed with
${myObject.name}: ${myObject.message}
.
The optional constructorOpt
argument accepts a function. If given, all frames
above constructorOpt
, including constructorOpt
, will be omitted from the
generated stack trace.
The constructorOpt
argument is useful for hiding implementation
details of error generation from an end user. For instance:
function MyError() {
Error.captureStackTrace(this, MyError);
}
// Without passing MyError to captureStackTrace, the MyError
// frame would show up in the .stack property. By passing
// the constructor, we omit that frame, and retain all frames below it.
new MyError().stack;
Error.stackTraceLimit
- {number}
The Error.stackTraceLimit
property specifies the number of stack frames
collected by a stack trace (whether generated by new Error().stack
or
Error.captureStackTrace(obj)
).
The default value is 10
but may be set to any valid JavaScript number. Changes
will affect any stack trace captured after the value has been changed.
If set to a non-number value, or set to a negative number, stack traces will not capture any frames.
error.code
- {string}
The error.code
property is a string label that identifies the kind of error.
error.code
is the most stable way to identify an error. It will only change
between major versions of Node.js. In contrast, error.message
strings may
change between any versions of Node.js. See Node.js Error Codes for details
about specific codes.
error.message
- {string}
The error.message
property is the string description of the error as set by
calling new Error(message)
. The message
passed to the constructor will also
appear in the first line of the stack trace of the Error
, however changing
this property after the Error
object is created may not change the first
line of the stack trace (for example, when error.stack
is read before this
property is changed).
const err = new Error('The message');
console.error(err.message);
// Prints: The message
error.stack
- {string}
The error.stack
property is a string describing the point in the code at which
the Error
was instantiated.
Error: Things keep happening!
at /home/gbusey/file.js:525:2
at Frobnicator.refrobulate (/home/gbusey/business-logic.js:424:21)
at Actor.<anonymous> (/home/gbusey/actors.js:400:8)
at increaseSynergy (/home/gbusey/actors.js:701:6)
The first line is formatted as <error class name>: <error message>
, and
is followed by a series of stack frames (each line beginning with "at ").
Each frame describes a call site within the code that lead to the error being
generated. V8 attempts to display a name for each function (by variable name,
function name, or object method name), but occasionally it will not be able to
find a suitable name. If V8 cannot determine a name for the function, only
location information will be displayed for that frame. Otherwise, the
determined function name will be displayed with location information appended
in parentheses.
Frames are only generated for JavaScript functions. If, for example, execution
synchronously passes through a C++ addon function called cheetahify
which
itself calls a JavaScript function, the frame representing the cheetahify
call
will not be present in the stack traces:
const cheetahify = require('./native-binding.node');
function makeFaster() {
// `cheetahify()` *synchronously* calls speedy.
cheetahify(function speedy() {
throw new Error('oh no!');
});
}
makeFaster();
// will throw:
// /home/gbusey/file.js:6
// throw new Error('oh no!');
// ^
// Error: oh no!
// at speedy (/home/gbusey/file.js:6:11)
// at makeFaster (/home/gbusey/file.js:5:3)
// at Object.<anonymous> (/home/gbusey/file.js:10:1)
// at Module._compile (module.js:456:26)
// at Object.Module._extensions..js (module.js:474:10)
// at Module.load (module.js:356:32)
// at Function.Module._load (module.js:312:12)
// at Function.Module.runMain (module.js:497:10)
// at startup (node.js:119:16)
// at node.js:906:3
The location information will be one of:
native
, if the frame represents a call internal to V8 (as in[].forEach
).plain-filename.js:line:column
, if the frame represents a call internal to Node.js./absolute/path/to/file.js:line:column
, if the frame represents a call in a user program, or its dependencies.
The string representing the stack trace is lazily generated when the
error.stack
property is accessed.
The number of frames captured by the stack trace is bounded by the smaller of
Error.stackTraceLimit
or the number of available frames on the current event
loop tick.
Class: AssertionError
- Extends: {errors.Error}
Indicates the failure of an assertion. For details, see
Class: assert.AssertionError
.
Class: RangeError
- Extends: {errors.Error}
Indicates that a provided argument was not within the set or range of acceptable values for a function; whether that is a numeric range, or outside the set of options for a given function parameter.
require('net').connect(-1);
// Throws "RangeError: "port" option should be >= 0 and < 65536: -1"
Node.js will generate and throw RangeError
instances immediately as a form
of argument validation.
Class: ReferenceError
- Extends: {errors.Error}
Indicates that an attempt is being made to access a variable that is not defined. Such errors commonly indicate typos in code, or an otherwise broken program.
While client code may generate and propagate these errors, in practice, only V8 will do so.
doesNotExist;
// Throws ReferenceError, doesNotExist is not a variable in this program.
Unless an application is dynamically generating and running code,
ReferenceError
instances should always be considered a bug in the code
or its dependencies.
Class: SyntaxError
- Extends: {errors.Error}
Indicates that a program is not valid JavaScript. These errors may only be
generated and propagated as a result of code evaluation. Code evaluation may
happen as a result of eval
, Function
, require
, or vm. These errors
are almost always indicative of a broken program.
try {
require('vm').runInThisContext('binary ! isNotOk');
} catch (err) {
// 'err' will be a SyntaxError.
}
SyntaxError
instances are unrecoverable in the context that created them –
they may only be caught by other contexts.
Class: SystemError
- Extends: {errors.Error}
Node.js generates system errors when exceptions occur within its runtime environment. These usually occur when an application violates an operating system constraint. For example, a system error will occur if an application attempts to read a file that does not exist.
address
{string} If present, the address to which a network connection failedcode
{string} The string error codedest
{string} If present, the file path destination when reporting a file system errorerrno
{number|string} The system-provided error numberinfo
{Object} If present, extra details about the error conditionmessage
{string} A system-provided human-readable description of the errorpath
{string} If present, the file path when reporting a file system errorport
{number} If present, the network connection port that is not availablesyscall
{string} The name of the system call that triggered the error
error.address
- {string}
If present, error.address
is a string describing the address to which a
network connection failed.
error.code
- {string}
The error.code
property is a string representing the error code.
error.dest
- {string}
If present, error.dest
is the file path destination when reporting a file
system error.
error.errno
- {string|number}
The error.errno
property is a number or a string. If it is a number, it is a
negative value which corresponds to the error code defined in
libuv Error handling
. See the libuv errno.h
header file
(deps/uv/include/uv/errno.h
in the Node.js source tree) for details. In case
of a string, it is the same as error.code
.
error.info
- {Object}
If present, error.info
is an object with details about the error condition.
error.message
- {string}
error.message
is a system-provided human-readable description of the error.
error.path
- {string}
If present, error.path
is a string containing a relevant invalid pathname.
error.port
- {number}
If present, error.port
is the network connection port that is not available.
error.syscall
- {string}
The error.syscall
property is a string describing the syscall that failed.
Common System Errors
This is a list of system errors commonly-encountered when writing a Node.js
program. For a comprehensive list, see the errno
(3) man page.
-
EACCES
(Permission denied): An attempt was made to access a file in a way forbidden by its file access permissions. -
EADDRINUSE
(Address already in use): An attempt to bind a server (net
,http
, orhttps
) to a local address failed due to another server on the local system already occupying that address. -
ECONNREFUSED
(Connection refused): No connection could be made because the target machine actively refused it. This usually results from trying to connect to a service that is inactive on the foreign host. -
ECONNRESET
(Connection reset by peer): A connection was forcibly closed by a peer. This normally results from a loss of the connection on the remote socket due to a timeout or reboot. Commonly encountered via thehttp
andnet
modules. -
EEXIST
(File exists): An existing file was the target of an operation that required that the target not exist. -
EISDIR
(Is a directory): An operation expected a file, but the given pathname was a directory. -
EMFILE
(Too many open files in system): Maximum number of file descriptors allowable on the system has been reached, and requests for another descriptor cannot be fulfilled until at least one has been closed. This is encountered when opening many files at once in parallel, especially on systems (in particular, macOS) where there is a low file descriptor limit for processes. To remedy a low limit, runulimit -n 2048
in the same shell that will run the Node.js process. -
ENOENT
(No such file or directory): Commonly raised byfs
operations to indicate that a component of the specified pathname does not exist. No entity (file or directory) could be found by the given path. -
ENOTDIR
(Not a directory): A component of the given pathname existed, but was not a directory as expected. Commonly raised byfs.readdir
. -
ENOTEMPTY
(Directory not empty): A directory with entries was the target of an operation that requires an empty directory, usuallyfs.unlink
. -
ENOTFOUND
(DNS lookup failed): Indicates a DNS failure of eitherEAI_NODATA
orEAI_NONAME
. This is not a standard POSIX error. -
EPERM
(Operation not permitted): An attempt was made to perform an operation that requires elevated privileges. -
EPIPE
(Broken pipe): A write on a pipe, socket, or FIFO for which there is no process to read the data. Commonly encountered at thenet
andhttp
layers, indicative that the remote side of the stream being written to has been closed. -
ETIMEDOUT
(Operation timed out): A connect or send request failed because the connected party did not properly respond after a period of time. Usually encountered byhttp
ornet
. Often a sign that asocket.end()
was not properly called.
Class: TypeError
- Extends {errors.Error}
Indicates that a provided argument is not an allowable type. For example,
passing a function to a parameter which expects a string would be considered
a TypeError
.
require('url').parse(() => { });
// Throws TypeError, since it expected a string.
Node.js will generate and throw TypeError
instances immediately as a form
of argument validation.
Exceptions vs. Errors
A JavaScript exception is a value that is thrown as a result of an invalid
operation or as the target of a throw
statement. While it is not required
that these values are instances of Error
or classes which inherit from
Error
, all exceptions thrown by Node.js or the JavaScript runtime will be
instances of Error
.
Some exceptions are unrecoverable at the JavaScript layer. Such exceptions
will always cause the Node.js process to crash. Examples include assert()
checks or abort()
calls in the C++ layer.
OpenSSL Errors
Errors originating in crypto
or tls
are of class Error
, and in addition to
the standard .code
and .message
properties, may have some additional
OpenSSL-specific properties.
error.opensslErrorStack
An array of errors that can give context to where in the OpenSSL library an error originates from.
error.function
The OpenSSL function the error originates in.
error.library
The OpenSSL library the error originates in.
error.reason
A human-readable string describing the reason for the error.
Node.js Error Codes
ERR_AMBIGUOUS_ARGUMENT
A function argument is being used in a way that suggests that the function
signature may be misunderstood. This is thrown by the assert
module when the
message
parameter in assert.throws(block, message)
matches the error message
thrown by block
because that usage suggests that the user believes message
is the expected message rather than the message the AssertionError
will
display if block
does not throw.
ERR_ARG_NOT_ITERABLE
An iterable argument (i.e. a value that works with for...of
loops) was
required, but not provided to a Node.js API.
ERR_ASSERTION
A special type of error that can be triggered whenever Node.js detects an
exceptional logic violation that should never occur. These are raised typically
by the assert
module.
ERR_ASYNC_CALLBACK
An attempt was made to register something that is not a function as an
AsyncHooks
callback.
ERR_ASYNC_TYPE
The type of an asynchronous resource was invalid. Users are also able to define their own types if using the public embedder API.
ERR_BROTLI_COMPRESSION_FAILED
Data passed to a Brotli stream was not successfully compressed.
ERR_BROTLI_INVALID_PARAM
An invalid parameter key was passed during construction of a Brotli stream.
ERR_BUFFER_CONTEXT_NOT_AVAILABLE
An attempt was made to create a Node.js Buffer
instance from addon or embedder
code, while in a JS engine Context that is not associated with a Node.js
instance. The data passed to the Buffer
method will have been released
by the time the method returns.
When encountering this error, a possible alternative to creating a Buffer
instance is to create a normal Uint8Array
, which only differs in the
prototype of the resulting object. Uint8Array
s are generally accepted in all
Node.js core APIs where Buffer
s are; they are available in all Contexts.
ERR_BUFFER_OUT_OF_BOUNDS
An operation outside the bounds of a Buffer
was attempted.
ERR_BUFFER_TOO_LARGE
An attempt has been made to create a Buffer
larger than the maximum allowed
size.
ERR_CANNOT_WATCH_SIGINT
Node.js was unable to watch for the SIGINT
signal.
ERR_CHILD_CLOSED_BEFORE_REPLY
A child process was closed before the parent received a reply.
ERR_CHILD_PROCESS_IPC_REQUIRED
Used when a child process is being forked without specifying an IPC channel.
ERR_CHILD_PROCESS_STDIO_MAXBUFFER
Used when the main process is trying to read data from the child process's
STDERR/STDOUT, and the data's length is longer than the maxBuffer
option.
ERR_CONSOLE_WRITABLE_STREAM
Console
was instantiated without stdout
stream, or Console
has a
non-writable stdout
or stderr
stream.
ERR_CONSTRUCT_CALL_REQUIRED
A constructor for a class was called without new
.
ERR_CONSTRUCT_CALL_INVALID
A class constructor was called that is not callable.
ERR_CPU_USAGE
The native call from process.cpuUsage
could not be processed.
ERR_CRYPTO_CUSTOM_ENGINE_NOT_SUPPORTED
A client certificate engine was requested that is not supported by the version of OpenSSL being used.
ERR_CRYPTO_ECDH_INVALID_FORMAT
An invalid value for the format
argument was passed to the crypto.ECDH()
class getPublicKey()
method.
ERR_CRYPTO_ECDH_INVALID_PUBLIC_KEY
An invalid value for the key
argument has been passed to the
crypto.ECDH()
class computeSecret()
method. It means that the public
key lies outside of the elliptic curve.
ERR_CRYPTO_ENGINE_UNKNOWN
An invalid crypto engine identifier was passed to
require('crypto').setEngine()
.
ERR_CRYPTO_FIPS_FORCED
The --force-fips
command-line argument was used but there was an attempt
to enable or disable FIPS mode in the crypto
module.
ERR_CRYPTO_FIPS_UNAVAILABLE
An attempt was made to enable or disable FIPS mode, but FIPS mode was not available.
ERR_CRYPTO_HASH_FINALIZED
hash.digest()
was called multiple times. The hash.digest()
method must
be called no more than one time per instance of a Hash
object.
ERR_CRYPTO_HASH_UPDATE_FAILED
hash.update()
failed for any reason. This should rarely, if ever, happen.
ERR_CRYPTO_INCOMPATIBLE_KEY
The given crypto keys are incompatible with the attempted operation.
ERR_CRYPTO_INCOMPATIBLE_KEY_OPTIONS
The selected public or private key encoding is incompatible with other options.
ERR_CRYPTO_INVALID_DIGEST
An invalid crypto digest algorithm was specified.
ERR_CRYPTO_INVALID_KEY_OBJECT_TYPE
The given crypto key object's type is invalid for the attempted operation.
ERR_CRYPTO_INVALID_STATE
A crypto method was used on an object that was in an invalid state. For
instance, calling cipher.getAuthTag()
before calling cipher.final()
.
ERR_CRYPTO_PBKDF2_ERROR
The PBKDF2 algorithm failed for unspecified reasons. OpenSSL does not provide more details and therefore neither does Node.js.
ERR_CRYPTO_SCRYPT_INVALID_PARAMETER
One or more crypto.scrypt()
or crypto.scryptSync()
parameters are
outside their legal range.
ERR_CRYPTO_SCRYPT_NOT_SUPPORTED
Node.js was compiled without scrypt
support. Not possible with the official
release binaries but can happen with custom builds, including distro builds.
ERR_CRYPTO_SIGN_KEY_REQUIRED
A signing key
was not provided to the sign.sign()
method.
ERR_CRYPTO_TIMING_SAFE_EQUAL_LENGTH
crypto.timingSafeEqual()
was called with Buffer
, TypedArray
, or
DataView
arguments of different lengths.
ERR_CRYPTO_UNKNOWN_CIPHER
An unknown cipher was specified.
ERR_CRYPTO_UNKNOWN_DH_GROUP
An unknown Diffie-Hellman group name was given. See
crypto.getDiffieHellman()
for a list of valid group names.
ERR_DIR_CLOSED
The fs.Dir
was previously closed.
ERR_DIR_CONCURRENT_OPERATION
A synchronous read or close call was attempted on an fs.Dir
which has
ongoing asynchronous operations.
ERR_DNS_SET_SERVERS_FAILED
c-ares
failed to set the DNS server.
ERR_DOMAIN_CALLBACK_NOT_AVAILABLE
The domain
module was not usable since it could not establish the required
error handling hooks, because
process.setUncaughtExceptionCaptureCallback()
had been called at an
earlier point in time.
ERR_DOMAIN_CANNOT_SET_UNCAUGHT_EXCEPTION_CAPTURE
process.setUncaughtExceptionCaptureCallback()
could not be called
because the domain
module has been loaded at an earlier point in time.
The stack trace is extended to include the point in time at which the
domain
module had been loaded.
ERR_ENCODING_INVALID_ENCODED_DATA
Data provided to TextDecoder()
API was invalid according to the encoding
provided.
ERR_ENCODING_NOT_SUPPORTED
Encoding provided to TextDecoder()
API was not one of the
WHATWG Supported Encodings.
ERR_EXECUTION_ENVIRONMENT_NOT_AVAILABLE
The JS execution context is not associated with a Node.js environment. This may occur when Node.js is used as an embedded library and some hooks for the JS engine are not set up properly.
ERR_FALSY_VALUE_REJECTION
A Promise
that was callbackified via util.callbackify()
was rejected with a
falsy value.
ERR_FS_FILE_TOO_LARGE
An attempt has been made to read a file whose size is larger than the maximum
allowed size for a Buffer
.
ERR_FS_INVALID_SYMLINK_TYPE
An invalid symlink type was passed to the fs.symlink()
or
fs.symlinkSync()
methods.
ERR_HTTP_HEADERS_SENT
An attempt was made to add more headers after the headers had already been sent.
ERR_HTTP_INVALID_HEADER_VALUE
An invalid HTTP header value was specified.
ERR_HTTP_INVALID_STATUS_CODE
Status code was outside the regular status code range (100-999).
ERR_HTTP_TRAILER_INVALID
The Trailer
header was set even though the transfer encoding does not support
that.
ERR_HTTP2_ALTSVC_INVALID_ORIGIN
HTTP/2 ALTSVC frames require a valid origin.
ERR_HTTP2_ALTSVC_LENGTH
HTTP/2 ALTSVC frames are limited to a maximum of 16,382 payload bytes.
ERR_HTTP2_CONNECT_AUTHORITY
For HTTP/2 requests using the CONNECT
method, the :authority
pseudo-header
is required.
ERR_HTTP2_CONNECT_PATH
For HTTP/2 requests using the CONNECT
method, the :path
pseudo-header is
forbidden.
ERR_HTTP2_CONNECT_SCHEME
For HTTP/2 requests using the CONNECT
method, the :scheme
pseudo-header is
forbidden.
ERR_HTTP2_ERROR
A non-specific HTTP/2 error has occurred.
ERR_HTTP2_GOAWAY_SESSION
New HTTP/2 Streams may not be opened after the Http2Session
has received a
GOAWAY
frame from the connected peer.
ERR_HTTP2_HEADERS_AFTER_RESPOND
An additional headers was specified after an HTTP/2 response was initiated.
ERR_HTTP2_HEADERS_SENT
An attempt was made to send multiple response headers.
ERR_HTTP2_HEADER_SINGLE_VALUE
Multiple values were provided for an HTTP/2 header field that was required to have only a single value.
ERR_HTTP2_INFO_STATUS_NOT_ALLOWED
Informational HTTP status codes (1xx
) may not be set as the response status
code on HTTP/2 responses.
ERR_HTTP2_INVALID_CONNECTION_HEADERS
HTTP/1 connection specific headers are forbidden to be used in HTTP/2 requests and responses.
ERR_HTTP2_INVALID_HEADER_VALUE
An invalid HTTP/2 header value was specified.
ERR_HTTP2_INVALID_INFO_STATUS
An invalid HTTP informational status code has been specified. Informational
status codes must be an integer between 100
and 199
(inclusive).
ERR_HTTP2_INVALID_ORIGIN
HTTP/2 ORIGIN
frames require a valid origin.
ERR_HTTP2_INVALID_PACKED_SETTINGS_LENGTH
Input Buffer
and Uint8Array
instances passed to the
http2.getUnpackedSettings()
API must have a length that is a multiple of
six.
ERR_HTTP2_INVALID_PSEUDOHEADER
Only valid HTTP/2 pseudoheaders (:status
, :path
, :authority
, :scheme
,
and :method
) may be used.
ERR_HTTP2_INVALID_SESSION
An action was performed on an Http2Session
object that had already been
destroyed.
ERR_HTTP2_INVALID_SETTING_VALUE
An invalid value has been specified for an HTTP/2 setting.
ERR_HTTP2_INVALID_STREAM
An operation was performed on a stream that had already been destroyed.
ERR_HTTP2_MAX_PENDING_SETTINGS_ACK
Whenever an HTTP/2 SETTINGS
frame is sent to a connected peer, the peer is
required to send an acknowledgment that it has received and applied the new
SETTINGS
. By default, a maximum number of unacknowledged SETTINGS
frames may
be sent at any given time. This error code is used when that limit has been
reached.
ERR_HTTP2_NESTED_PUSH
An attempt was made to initiate a new push stream from within a push stream. Nested push streams are not permitted.
ERR_HTTP2_NO_SOCKET_MANIPULATION
An attempt was made to directly manipulate (read, write, pause, resume, etc.) a
socket attached to an Http2Session
.
ERR_HTTP2_ORIGIN_LENGTH
HTTP/2 ORIGIN
frames are limited to a length of 16382 bytes.
ERR_HTTP2_OUT_OF_STREAMS
The number of streams created on a single HTTP/2 session reached the maximum limit.
ERR_HTTP2_PAYLOAD_FORBIDDEN
A message payload was specified for an HTTP response code for which a payload is forbidden.
ERR_HTTP2_PING_CANCEL
An HTTP/2 ping was canceled.
ERR_HTTP2_PING_LENGTH
HTTP/2 ping payloads must be exactly 8 bytes in length.
ERR_HTTP2_PSEUDOHEADER_NOT_ALLOWED
An HTTP/2 pseudo-header has been used inappropriately. Pseudo-headers are header
key names that begin with the :
prefix.
ERR_HTTP2_PUSH_DISABLED
An attempt was made to create a push stream, which had been disabled by the client.
ERR_HTTP2_SEND_FILE
An attempt was made to use the Http2Stream.prototype.responseWithFile()
API to
send a directory.
ERR_HTTP2_SEND_FILE_NOSEEK
An attempt was made to use the Http2Stream.prototype.responseWithFile()
API to
send something other than a regular file, but offset
or length
options were
provided.
ERR_HTTP2_SESSION_ERROR
The Http2Session
closed with a non-zero error code.
ERR_HTTP2_SETTINGS_CANCEL
The Http2Session
settings canceled.
ERR_HTTP2_SOCKET_BOUND
An attempt was made to connect a Http2Session
object to a net.Socket
or
tls.TLSSocket
that had already been bound to another Http2Session
object.
ERR_HTTP2_SOCKET_UNBOUND
An attempt was made to use the socket
property of an Http2Session
that
has already been closed.
ERR_HTTP2_STATUS_101
Use of the 101
Informational status code is forbidden in HTTP/2.
ERR_HTTP2_STATUS_INVALID
An invalid HTTP status code has been specified. Status codes must be an integer
between 100
and 599
(inclusive).
ERR_HTTP2_STREAM_CANCEL
An Http2Stream
was destroyed before any data was transmitted to the connected
peer.
ERR_HTTP2_STREAM_ERROR
A non-zero error code was been specified in an RST_STREAM
frame.
ERR_HTTP2_STREAM_SELF_DEPENDENCY
When setting the priority for an HTTP/2 stream, the stream may be marked as a dependency for a parent stream. This error code is used when an attempt is made to mark a stream and dependent of itself.
ERR_HTTP2_TRAILERS_ALREADY_SENT
Trailing headers have already been sent on the Http2Stream
.
ERR_HTTP2_TRAILERS_NOT_READY
The http2stream.sendTrailers()
method cannot be called until after the
'wantTrailers'
event is emitted on an Http2Stream
object. The
'wantTrailers'
event will only be emitted if the waitForTrailers
option
is set for the Http2Stream
.
ERR_HTTP2_UNSUPPORTED_PROTOCOL
http2.connect()
was passed a URL that uses any protocol other than http:
or
https:
.
ERR_INTERNAL_ASSERTION
There was a bug in Node.js or incorrect usage of Node.js internals. To fix the error, open an issue at https://github.com/nodejs/node/issues.
ERR_INCOMPATIBLE_OPTION_PAIR
An option pair is incompatible with each other and cannot be used at the same time.
ERR_INPUT_TYPE_NOT_ALLOWED
Stability: 1 - Experimental
The --input-type
flag was used to attempt to execute a file. This flag can
only be used with input via --eval
, --print
or STDIN
.
ERR_INSPECTOR_ALREADY_CONNECTED
While using the inspector
module, an attempt was made to connect when the
inspector was already connected.
ERR_INSPECTOR_CLOSED
While using the inspector
module, an attempt was made to use the inspector
after the session had already closed.
ERR_INSPECTOR_COMMAND
An error occurred while issuing a command via the inspector
module.
ERR_INSPECTOR_NOT_ACTIVE
The inspector
is not active when inspector.waitForDebugger()
is called.
ERR_INSPECTOR_NOT_AVAILABLE
The inspector
module is not available for use.
ERR_INSPECTOR_NOT_CONNECTED
While using the inspector
module, an attempt was made to use the inspector
before it was connected.
ERR_INSPECTOR_NOT_WORKER
An API was called on the main thread that can only be used from the worker thread.
ERR_INVALID_ADDRESS_FAMILY
The provided address family is not understood by the Node.js API.
ERR_INVALID_ARG_TYPE
An argument of the wrong type was passed to a Node.js API.
ERR_INVALID_ARG_VALUE
An invalid or unsupported value was passed for a given argument.
ERR_INVALID_ASYNC_ID
An invalid asyncId
or triggerAsyncId
was passed using AsyncHooks
. An id
less than -1 should never happen.
ERR_INVALID_BUFFER_SIZE
A swap was performed on a Buffer
but its size was not compatible with the
operation.
ERR_INVALID_CALLBACK
A callback function was required but was not been provided to a Node.js API.
ERR_INVALID_CHAR
Invalid characters were detected in headers.
ERR_INVALID_CURSOR_POS
A cursor on a given stream cannot be moved to a specified row without a specified column.
ERR_INVALID_FD
A file descriptor ('fd') was not valid (e.g. it was a negative value).
ERR_INVALID_FD_TYPE
A file descriptor ('fd') type was not valid.
ERR_INVALID_FILE_URL_HOST
A Node.js API that consumes file:
URLs (such as certain functions in the
fs
module) encountered a file URL with an incompatible host. This
situation can only occur on Unix-like systems where only localhost
or an empty
host is supported.
ERR_INVALID_FILE_URL_PATH
A Node.js API that consumes file:
URLs (such as certain functions in the
fs
module) encountered a file URL with an incompatible path. The exact
semantics for determining whether a path can be used is platform-dependent.
ERR_INVALID_HANDLE_TYPE
An attempt was made to send an unsupported "handle" over an IPC communication
channel to a child process. See subprocess.send()
and process.send()
for more information.
ERR_INVALID_HTTP_TOKEN
An invalid HTTP token was supplied.
ERR_INVALID_IP_ADDRESS
An IP address is not valid.
ERR_INVALID_MODULE_SPECIFIER
The imported module string is an invalid URL, package name, or package subpath specifier.
ERR_INVALID_OPT_VALUE
An invalid or unexpected value was passed in an options object.
ERR_INVALID_OPT_VALUE_ENCODING
An invalid or unknown file encoding was passed.
ERR_INVALID_PACKAGE_CONFIG
An invalid package.json
file was found which failed parsing.
ERR_INVALID_PACKAGE_TARGET
The package.json
exports field contains an invalid target mapping value
for the attempted module resolution.
ERR_INVALID_PERFORMANCE_MARK
While using the Performance Timing API (perf_hooks
), a performance mark is
invalid.
ERR_INVALID_PROTOCOL
An invalid options.protocol
was passed to http.request()
.
ERR_INVALID_REPL_EVAL_CONFIG
Both breakEvalOnSigint
and eval
options were set in the REPL
config,
which is not supported.
ERR_INVALID_REPL_INPUT
The input may not be used in the REPL
. All prohibited inputs are
documented in the REPL
's documentation.
ERR_INVALID_RETURN_PROPERTY
Thrown in case a function option does not provide a valid value for one of its returned object properties on execution.
ERR_INVALID_RETURN_PROPERTY_VALUE
Thrown in case a function option does not provide an expected value type for one of its returned object properties on execution.
ERR_INVALID_RETURN_VALUE
Thrown in case a function option does not return an expected value type on execution, such as when a function is expected to return a promise.
ERR_INVALID_SYNC_FORK_INPUT
A Buffer
, TypedArray
, DataView
or string
was provided as stdio input to
an asynchronous fork. See the documentation for the child_process
module
for more information.
ERR_INVALID_THIS
A Node.js API function was called with an incompatible this
value.
const urlSearchParams = new URLSearchParams('foo=bar&baz=new');
const buf = Buffer.alloc(1);
urlSearchParams.has.call(buf, 'foo');
// Throws a TypeError with code 'ERR_INVALID_THIS'
ERR_INVALID_TRANSFER_OBJECT
An invalid transfer object was passed to postMessage()
.
ERR_INVALID_TUPLE
An element in the iterable
provided to the WHATWG
URLSearchParams
constructor did not
represent a [name, value]
tuple – that is, if an element is not iterable, or
does not consist of exactly two elements.
ERR_INVALID_URI
An invalid URI was passed.
ERR_INVALID_URL
An invalid URL was passed to the WHATWG
URL
constructor to be parsed. The thrown error object
typically has an additional property 'input'
that contains the URL that failed
to parse.
ERR_INVALID_URL_SCHEME
An attempt was made to use a URL of an incompatible scheme (protocol) for a
specific purpose. It is only used in the WHATWG URL API support in the
fs
module (which only accepts URLs with 'file'
scheme), but may be used
in other Node.js APIs as well in the future.
ERR_IPC_CHANNEL_CLOSED
An attempt was made to use an IPC communication channel that was already closed.
ERR_IPC_DISCONNECTED
An attempt was made to disconnect an IPC communication channel that was already
disconnected. See the documentation for the child_process
module
for more information.
ERR_IPC_ONE_PIPE
An attempt was made to create a child Node.js process using more than one IPC
communication channel. See the documentation for the child_process
module
for more information.
ERR_IPC_SYNC_FORK
An attempt was made to open an IPC communication channel with a synchronously
forked Node.js process. See the documentation for the child_process
module
for more information.
ERR_MANIFEST_ASSERT_INTEGRITY
An attempt was made to load a resource, but the resource did not match the integrity defined by the policy manifest. See the documentation for policy manifests for more information.
ERR_MANIFEST_DEPENDENCY_MISSING
An attempt was made to load a resource, but the resource was not listed as a dependency from the location that attempted to load it. See the documentation for policy manifests for more information.
ERR_MANIFEST_INTEGRITY_MISMATCH
An attempt was made to load a policy manifest, but the manifest had multiple entries for a resource which did not match each other. Update the manifest entries to match in order to resolve this error. See the documentation for policy manifests for more information.
ERR_MANIFEST_INVALID_RESOURCE_FIELD
A policy manifest resource had an invalid value for one of its fields. Update the manifest entry to match in order to resolve this error. See the documentation for policy manifests for more information.
ERR_MANIFEST_PARSE_POLICY
An attempt was made to load a policy manifest, but the manifest was unable to be parsed. See the documentation for policy manifests for more information.
ERR_MANIFEST_TDZ
An attempt was made to read from a policy manifest, but the manifest initialization has not yet taken place. This is likely a bug in Node.js.
ERR_MANIFEST_UNKNOWN_ONERROR
A policy manifest was loaded, but had an unknown value for its "onerror" behavior. See the documentation for policy manifests for more information.
ERR_MEMORY_ALLOCATION_FAILED
An attempt was made to allocate memory (usually in the C++ layer) but it failed.
ERR_METHOD_NOT_IMPLEMENTED
A method is required but not implemented.
ERR_MISSING_ARGS
A required argument of a Node.js API was not passed. This is only used for
strict compliance with the API specification (which in some cases may accept
func(undefined)
but not func()
). In most native Node.js APIs,
func(undefined)
and func()
are treated identically, and the
ERR_INVALID_ARG_TYPE
error code may be used instead.
ERR_MISSING_DYNAMIC_INSTANTIATE_HOOK
Stability: 1 - Experimental
An ES Module loader hook specified format: 'dynamic'
but did not provide
a dynamicInstantiate
hook.
ERR_MISSING_OPTION
For APIs that accept options objects, some options might be mandatory. This code is thrown if a required option is missing.
ERR_MISSING_MESSAGE_PORT_IN_TRANSFER_LIST
A MessagePort
was found in the object passed to a postMessage()
call,
but not provided in the transferList
for that call.
ERR_MISSING_PASSPHRASE
An attempt was made to read an encrypted key without specifying a passphrase.
ERR_MISSING_PLATFORM_FOR_WORKER
The V8 platform used by this instance of Node.js does not support creating Workers. This is caused by lack of embedder support for Workers. In particular, this error will not occur with standard builds of Node.js.
ERR_MODULE_NOT_FOUND
Stability: 1 - Experimental
An ES Module could not be resolved.
ERR_MULTIPLE_CALLBACK
A callback was called more than once.
A callback is almost always meant to only be called once as the query can either be fulfilled or rejected but not both at the same time. The latter would be possible by calling a callback more than once.
ERR_NAPI_CONS_FUNCTION
While using N-API
, a constructor passed was not a function.
ERR_NAPI_INVALID_DATAVIEW_ARGS
While calling napi_create_dataview()
, a given offset
was outside the bounds
of the dataview or offset + length
was larger than a length of given buffer
.
ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT
While calling napi_create_typedarray()
, the provided offset
was not a
multiple of the element size.
ERR_NAPI_INVALID_TYPEDARRAY_LENGTH
While calling napi_create_typedarray()
, (length * size_of_element) + byte_offset
was larger than the length of given buffer
.
ERR_NAPI_TSFN_CALL_JS
An error occurred while invoking the JavaScript portion of the thread-safe function.
ERR_NAPI_TSFN_GET_UNDEFINED
An error occurred while attempting to retrieve the JavaScript undefined
value.
ERR_NAPI_TSFN_START_IDLE_LOOP
On the main thread, values are removed from the queue associated with the thread-safe function in an idle loop. This error indicates that an error has occurred when attempting to start the loop.
ERR_NAPI_TSFN_STOP_IDLE_LOOP
Once no more items are left in the queue, the idle loop must be suspended. This error indicates that the idle loop has failed to stop.
ERR_NO_CRYPTO
An attempt was made to use crypto features while Node.js was not compiled with OpenSSL crypto support.
ERR_NO_ICU
An attempt was made to use features that require ICU, but Node.js was not compiled with ICU support.
ERR_NON_CONTEXT_AWARE_DISABLED
A non-context-aware native addon was loaded in a process that disallows them.
ERR_OUT_OF_RANGE
A given value is out of the accepted range.
ERR_PACKAGE_PATH_NOT_EXPORTED
The package.json
exports field does not export the requested subpath.
Because exports are encapsulated, private internal modules that are not exported
cannot be imported through the package resolution, unless using an absolute URL.
ERR_PROTO_ACCESS
Accessing Object.prototype.__proto__
has been forbidden using
--disable-proto=throw
. Object.getPrototypeOf
and
Object.setPrototypeOf
should be used to get and set the prototype of an
object.
ERR_REQUIRE_ESM
Stability: 1 - Experimental
An attempt was made to require()
an ES Module.
ERR_SCRIPT_EXECUTION_INTERRUPTED
Script execution was interrupted by SIGINT
(For example, when Ctrl+C was
pressed).
ERR_SCRIPT_EXECUTION_TIMEOUT
Script execution timed out, possibly due to bugs in the script being executed.
ERR_SERVER_ALREADY_LISTEN
The server.listen()
method was called while a net.Server
was already
listening. This applies to all instances of net.Server
, including HTTP, HTTPS,
and HTTP/2 Server
instances.
ERR_SERVER_NOT_RUNNING
The server.close()
method was called when a net.Server
was not
running. This applies to all instances of net.Server
, including HTTP, HTTPS,
and HTTP/2 Server
instances.
ERR_SOCKET_ALREADY_BOUND
An attempt was made to bind a socket that has already been bound.
ERR_SOCKET_BAD_BUFFER_SIZE
An invalid (negative) size was passed for either the recvBufferSize
or
sendBufferSize
options in dgram.createSocket()
.
ERR_SOCKET_BAD_PORT
An API function expecting a port >= 0 and < 65536 received an invalid value.
ERR_SOCKET_BAD_TYPE
An API function expecting a socket type (udp4
or udp6
) received an invalid
value.
ERR_SOCKET_BUFFER_SIZE
While using dgram.createSocket()
, the size of the receive or send Buffer
could not be determined.
ERR_SOCKET_CANNOT_SEND
Data could be sent on a socket.
ERR_SOCKET_CLOSED
An attempt was made to operate on an already closed socket.
ERR_SOCKET_DGRAM_IS_CONNECTED
A dgram.connect()
call was made on an already connected socket.
ERR_SOCKET_DGRAM_NOT_CONNECTED
A dgram.disconnect()
or dgram.remoteAddress()
call was made on a
disconnected socket.
ERR_SOCKET_DGRAM_NOT_RUNNING
A call was made and the UDP subsystem was not running.
ERR_SRI_PARSE
A string was provided for a Subresource Integrity check, but was unable to be parsed. Check the format of integrity attributes by looking at the Subresource Integrity specification.
ERR_STREAM_CANNOT_PIPE
An attempt was made to call stream.pipe()
on a Writable
stream.
ERR_STREAM_DESTROYED
A stream method was called that cannot complete because the stream was
destroyed using stream.destroy()
.
ERR_STREAM_NULL_VALUES
An attempt was made to call stream.write()
with a null
chunk.
ERR_STREAM_PREMATURE_CLOSE
An error returned by stream.finished()
and stream.pipeline()
, when a stream
or a pipeline ends non gracefully with no explicit error.
ERR_STREAM_PUSH_AFTER_EOF
An attempt was made to call stream.push()
after a null
(EOF) had been
pushed to the stream.
ERR_STREAM_UNSHIFT_AFTER_END_EVENT
An attempt was made to call stream.unshift()
after the 'end'
event was
emitted.
ERR_STREAM_WRAP
Prevents an abort if a string decoder was set on the Socket or if the decoder
is in objectMode
.
const Socket = require('net').Socket;
const instance = new Socket();
instance.setEncoding('utf8');
ERR_STREAM_WRITE_AFTER_END
An attempt was made to call stream.write()
after stream.end()
has been
called.
ERR_STRING_TOO_LONG
An attempt has been made to create a string longer than the maximum allowed length.
ERR_SYNTHETIC
An artificial error object used to capture the call stack for diagnostic reports.
ERR_SYSTEM_ERROR
An unspecified or non-specific system error has occurred within the Node.js
process. The error object will have an err.info
object property with
additional details.
ERR_TLS_CERT_ALTNAME_INVALID
While using TLS, the host name/IP of the peer did not match any of the
subjectAltNames
in its certificate.
ERR_TLS_DH_PARAM_SIZE
While using TLS, the parameter offered for the Diffie-Hellman (DH
)
key-agreement protocol is too small. By default, the key length must be greater
than or equal to 1024 bits to avoid vulnerabilities, even though it is strongly
recommended to use 2048 bits or larger for stronger security.
ERR_TLS_HANDSHAKE_TIMEOUT
A TLS/SSL handshake timed out. In this case, the server must also abort the connection.
ERR_TLS_INVALID_CONTEXT
The context must be a SecureContext
.
ERR_TLS_INVALID_STATE
The TLS socket must be connected and securily established. Ensure the 'secure' event is emitted before continuing.
ERR_TLS_INVALID_PROTOCOL_METHOD
The specified secureProtocol
method is invalid. It is either unknown, or
disabled because it is insecure.
ERR_TLS_INVALID_PROTOCOL_VERSION
Valid TLS protocol versions are 'TLSv1'
, 'TLSv1.1'
, or 'TLSv1.2'
.
ERR_TLS_PROTOCOL_VERSION_CONFLICT
Attempting to set a TLS protocol minVersion
or maxVersion
conflicts with an
attempt to set the secureProtocol
explicitly. Use one mechanism or the other.
ERR_TLS_RENEGOTIATION_DISABLED
An attempt was made to renegotiate TLS on a socket instance with TLS disabled.
ERR_TLS_REQUIRED_SERVER_NAME
While using TLS, the server.addContext()
method was called without providing
a host name in the first parameter.
ERR_TLS_SESSION_ATTACK
An excessive amount of TLS renegotiations is detected, which is a potential vector for denial-of-service attacks.
ERR_TLS_SNI_FROM_SERVER
An attempt was made to issue Server Name Indication from a TLS server-side socket, which is only valid from a client.
ERR_TLS_PSK_SET_IDENTIY_HINT_FAILED
Failed to set PSK identity hint. Hint may be too long.
ERR_TRACE_EVENTS_CATEGORY_REQUIRED
The trace_events.createTracing()
method requires at least one trace event
category.
ERR_TRACE_EVENTS_UNAVAILABLE
The trace_events
module could not be loaded because Node.js was compiled with
the --without-v8-platform
flag.
ERR_TRANSFERRING_EXTERNALIZED_SHAREDARRAYBUFFER
A SharedArrayBuffer
whose memory is not managed by the JavaScript engine
or by Node.js was encountered during serialization. Such a SharedArrayBuffer
cannot be serialized.
This can only happen when native addons create SharedArrayBuffer
s in
"externalized" mode, or put existing SharedArrayBuffer
into externalized mode.
ERR_TRANSFORM_ALREADY_TRANSFORMING
A Transform
stream finished while it was still transforming.
ERR_TRANSFORM_WITH_LENGTH_0
A Transform
stream finished with data still in the write buffer.
ERR_TTY_INIT_FAILED
The initialization of a TTY failed due to a system error.
ERR_UNCAUGHT_EXCEPTION_CAPTURE_ALREADY_SET
process.setUncaughtExceptionCaptureCallback()
was called twice,
without first resetting the callback to null
.
This error is designed to prevent accidentally overwriting a callback registered from another module.
ERR_UNESCAPED_CHARACTERS
A string that contained unescaped characters was received.
ERR_UNHANDLED_ERROR
An unhandled error occurred (for instance, when an 'error'
event is emitted
by an EventEmitter
but an 'error'
handler is not registered).
ERR_UNKNOWN_BUILTIN_MODULE
Used to identify a specific kind of internal Node.js error that should not typically be triggered by user code. Instances of this error point to an internal bug within the Node.js binary itself.
ERR_UNKNOWN_CREDENTIAL
A Unix group or user identifier that does not exist was passed.
ERR_UNKNOWN_ENCODING
An invalid or unknown encoding option was passed to an API.
ERR_UNKNOWN_FILE_EXTENSION
Stability: 1 - Experimental
An attempt was made to load a module with an unknown or unsupported file extension.
ERR_UNKNOWN_MODULE_FORMAT
Stability: 1 - Experimental
An attempt was made to load a module with an unknown or unsupported format.
ERR_UNKNOWN_SIGNAL
An invalid or unknown process signal was passed to an API expecting a valid
signal (such as subprocess.kill()
).
ERR_UNSUPPORTED_DIR_IMPORT
import
a directory URL is unsupported. Instead, you can
self-reference a package using its name and define a custom subpath in
the "exports"
field of the package.json
file.
import './'; // unsupported
import './index.js'; // supported
import 'package-name'; // supported
ERR_UNSUPPORTED_ESM_URL_SCHEME
import
with URL schemes other than file
and data
is unsupported.
ERR_V8BREAKITERATOR
The V8 BreakIterator
API was used but the full ICU data set is not installed.
ERR_VALID_PERFORMANCE_ENTRY_TYPE
While using the Performance Timing API (perf_hooks
), no valid performance
entry types were found.
ERR_VM_DYNAMIC_IMPORT_CALLBACK_MISSING
A dynamic import callback was not specified.
ERR_VM_MODULE_ALREADY_LINKED
The module attempted to be linked is not eligible for linking, because of one of the following reasons:
- It has already been linked (
linkingStatus
is'linked'
) - It is being linked (
linkingStatus
is'linking'
) - Linking has failed for this module (
linkingStatus
is'errored'
)
ERR_VM_MODULE_CACHED_DATA_REJECTED
The cachedData
option passed to a module constructor is invalid.
ERR_VM_MODULE_CANNOT_CREATE_CACHED_DATA
Cached data cannot be created for modules which have already been evaluated.
ERR_VM_MODULE_DIFFERENT_CONTEXT
The module being returned from the linker function is from a different context than the parent module. Linked modules must share the same context.
ERR_VM_MODULE_LINKING_ERRORED
The linker function returned a module for which linking has failed.
ERR_VM_MODULE_NOT_MODULE
The fulfilled value of a linking promise is not a vm.Module
object.
ERR_VM_MODULE_STATUS
The current module's status does not allow for this operation. The specific meaning of the error depends on the specific function.
ERR_WASI_ALREADY_STARTED
The WASI instance has already started.
ERR_WASI_NOT_STARTED
The WASI instance has not been started.
ERR_WORKER_INIT_FAILED
The Worker
initialization failed.
ERR_WORKER_INVALID_EXEC_ARGV
The execArgv
option passed to the Worker
constructor contains
invalid flags.
ERR_WORKER_NOT_RUNNING
An operation failed because the Worker
instance is not currently running.
ERR_WORKER_OUT_OF_MEMORY
The Worker
instance terminated because it reached its memory limit.
ERR_WORKER_PATH
The path for the main script of a worker is neither an absolute path
nor a relative path starting with ./
or ../
.
ERR_WORKER_UNSERIALIZABLE_ERROR
All attempts at serializing an uncaught exception from a worker thread failed.
ERR_WORKER_UNSUPPORTED_EXTENSION
The pathname used for the main script of a worker has an unknown file extension.
ERR_WORKER_UNSUPPORTED_OPERATION
The requested functionality is not supported in worker threads.
ERR_ZLIB_INITIALIZATION_FAILED
Creation of a zlib
object failed due to incorrect configuration.
HPE_HEADER_OVERFLOW
Too much HTTP header data was received. In order to protect against malicious or
malconfigured clients, if more than 8KB of HTTP header data is received then
HTTP parsing will abort without a request or response object being created, and
an Error
with this code will be emitted.
MODULE_NOT_FOUND
A module file could not be resolved while attempting a require()
or
import
operation.
Legacy Node.js Error Codes
Stability: 0 - Deprecated. These error codes are either inconsistent, or have been removed.
ERR_CANNOT_TRANSFER_OBJECT
The value passed to postMessage()
contained an object that is not supported
for transferring.
ERR_CLOSED_MESSAGE_PORT
There was an attempt to use a MessagePort
instance in a closed
state, usually after .close()
has been called.
ERR_CRYPTO_HASH_DIGEST_NO_UTF16
The UTF-16 encoding was used with hash.digest()
. While the
hash.digest()
method does allow an encoding
argument to be passed in,
causing the method to return a string rather than a Buffer
, the UTF-16
encoding (e.g. ucs
or utf16le
) is not supported.
ERR_HTTP2_FRAME_ERROR
Used when a failure occurs sending an individual frame on the HTTP/2 session.
ERR_HTTP2_HEADERS_OBJECT
Used when an HTTP/2 Headers Object is expected.
ERR_HTTP2_HEADER_REQUIRED
Used when a required header is missing in an HTTP/2 message.
ERR_HTTP2_INFO_HEADERS_AFTER_RESPOND
HTTP/2 informational headers must only be sent prior to calling the
Http2Stream.prototype.respond()
method.
ERR_HTTP2_STREAM_CLOSED
Used when an action has been performed on an HTTP/2 Stream that has already been closed.
ERR_HTTP_INVALID_CHAR
Used when an invalid character is found in an HTTP response status message (reason phrase).
ERR_INDEX_OUT_OF_RANGE
A given index was out of the accepted range (e.g. negative offsets).
ERR_NAPI_CONS_PROTOTYPE_OBJECT
Used by the N-API
when Constructor.prototype
is not an object.
ERR_NO_LONGER_SUPPORTED
A Node.js API was called in an unsupported manner, such as
Buffer.write(string, encoding, offset[, length])
.
ERR_OUTOFMEMORY
Used generically to identify that an operation caused an out of memory condition.
ERR_PARSE_HISTORY_DATA
The repl
module was unable to parse data from the REPL history file.
ERR_STDERR_CLOSE
An attempt was made to close the process.stderr
stream. By design, Node.js
does not allow stdout
or stderr
streams to be closed by user code.
ERR_STDOUT_CLOSE
An attempt was made to close the process.stdout
stream. By design, Node.js
does not allow stdout
or stderr
streams to be closed by user code.
ERR_STREAM_READ_NOT_IMPLEMENTED
Used when an attempt is made to use a readable stream that has not implemented
readable._read()
.
ERR_TLS_RENEGOTIATION_FAILED
Used when a TLS renegotiation request has failed in a non-specific way.
ERR_UNKNOWN_BUILTIN_MODULE
The 'ERR_UNKNOWN_BUILTIN_MODULE'
error code is used to identify a specific
kind of internal Node.js error that should not typically be triggered by user
code. Instances of this error point to an internal bug within the Node.js
binary itself.
ERR_UNKNOWN_STDIN_TYPE
An attempt was made to launch a Node.js process with an unknown stdin
file
type. This error is usually an indication of a bug within Node.js itself,
although it is possible for user code to trigger it.
ERR_UNKNOWN_STREAM_TYPE
An attempt was made to launch a Node.js process with an unknown stdout
or
stderr
file type. This error is usually an indication of a bug within Node.js
itself, although it is possible for user code to trigger it.
ERR_VALUE_OUT_OF_RANGE
Used when a given value is out of the accepted range.
ERR_VM_MODULE_NOT_LINKED
The module must be successfully linked before instantiation.
ERR_ZLIB_BINDING_CLOSED
Used when an attempt is made to use a zlib
object after it has already been
closed.
Other error codes
These errors have never been released, but had been present on master between releases.
ERR_ENTRY_TYPE_MISMATCH
Stability: 1 - Experimental
The --entry-type=commonjs
flag was used to attempt to execute an .mjs
file
or a .js
file where the nearest parent package.json
contains
"type": "module"
; or
the --entry-type=module
flag was used to attempt to execute a .cjs
file or
a .js
file where the nearest parent package.json
either lacks a "type"
field or contains "type": "commonjs"
.
ERR_FS_WATCHER_ALREADY_STARTED
An attempt was made to start a watcher returned by fs.watch()
that has
already been started.
ERR_FS_WATCHER_NOT_STARTED
An attempt was made to initiate operations on a watcher returned by
fs.watch()
that has not yet been started.
ERR_HTTP2_ALREADY_SHUTDOWN
Occurs with multiple attempts to shutdown an HTTP/2 session.
ERR_HTTP2_ERROR
A non-specific HTTP/2 error has occurred.
ERR_INVALID_REPL_HISTORY
Used in the repl
in case the old history file is used and an error occurred
while trying to read and parse it.
ERR_INVALID_REPL_TYPE
Stability: 1 - Experimental
The --entry-type=...
flag is not compatible with the Node.js REPL.
ERR_MISSING_DYNAMIC_INSTANTIATE_HOOK
Used when an ES Module loader hook specifies format: 'dynamic'
but does
not provide a dynamicInstantiate
hook.
ERR_STREAM_HAS_STRINGDECODER
Used to prevent an abort if a string decoder was set on the Socket.
const Socket = require('net').Socket;
const instance = new Socket();
instance.setEncoding('utf8');
ERR_STRING_TOO_LARGE
An attempt has been made to create a string larger than the maximum allowed size.
ERR_TTY_WRITABLE_NOT_READABLE
This Error
is thrown when a read is attempted on a TTY WriteStream
,
such as process.stdout.on('data')
.