Throw er unhandled error event node js

How to Fix «throw er; // Unhandled ‘error’ event»?

Engineer. Maker. Open Source Fan. Backpacker

Published on July 23, 2022 by Peter Thaleikis

Some errors are easy and simple. Quick fixes you get resolved in minutes. Others aren’t and you got to dig in for much longer than you would like to. This was one of these for me. I’m sharing my solution here to make it a bit easier for other developers.

This problem seems to affect especially Linux users like myself. I can’t confirm this for sure as I run only Linux 🐧️ On my elementary the issue usually comes up when I try to run npm/yarn commands which are supposed to watch file changes (e.g. CSS/SCSS or JavaScript files). The problem affects all frameworks from VueJS, to React and Angular. The related dev — and prod -commands work fine. It’s only affecting watch -command and appears to be linked to a file-system incompatibility when watching file changes.

This particular case problem arises while using my swiss armyknife build tool Laravel Mix on a project. When running npm run watch (actually yarn watch ) I get this error message after the compile step is finish:

The line number depends on the exact libraries used in the project, but the events.js filename or throw er; // unhandled ‘error’ event are usually part of the error.

If supported, watch-poll often resolves the issue. But some libraries, like my starter for eleventy (this blog), aren’t supporting poll and I needed to resort to a different approach. After spending some time researching and trying I’ve found a solution which works for now. I remove the node_modules -folder ( rm -rf node_modules ) and force-clear the NPM cache ( npm cache clear —force ) before reinstalling the node dependencies. Summarized in the following steps:

Please note: This removes also the lock-file. Thereby updating your project, make sure to test everything before you push the changes to production 🙏️

Update #1: Solution: Stop all other «watch»-processes

If you have a number of node processes running this might be part of your issue. I’ve noticed the problem coming up more often if I’ve got a number of watch processes (for other projects) running. After stopping these and clearing the files as described above the issues was resolved.

Update #2 (2020-03-04): Error: ENOSPC: System limit for number of file watchers reached, watch ‘src/assets’

With a recent update of my dependencies, I’ve noticed a new, better understandable wording for the known error. This points you much faster in the right direction. Again, I’ve been able to resolve the issue using the approach mentioned above.

Update #3 (2020-04-23): Increase allowed file handles

By chance I stumbled across a solution to increase the number of allowed file handles. This actually came with my recent trail of Microsoft Studio Code for Linux. It thrown a familiar sounding error:

Microsoft recommended the following to increase the number of allowed file handles. You can do by updating your /etc/sysctl.conf file. The detail steps are lined out here.

Update #4: Do you prefer a video?

More a video guy? Someone also made a video based on the content of article:

Update #5:

This might also come with a blocked port an app is try to listen to. In this case your error message might look like this:

The port at the end, here 5000 , can vary.

If this looks like your problem, you might want to check what is listening on the port in question. Simply open the port with port, e.g. localhost:5000 , in your browser. After turning of the application in question or changing your port this problem should be resolved.

By the way

I love the web and building stuff! The web still has lots amazing open-source libraries and actually innovative side-projects. Once in a while, I share these awesome web-findings via email. If this sounds like something you are into, subscribe below:

Published under the following tags: JavaScript Linux

Источник

Fixing nodemon ‘Error: listen EADDRINUSE: address in use’

Has this ever happened to you?

You go to start up your server with npm start and you get the below error message

Exit fullscreen mode

Luckily there is a solution!

This error occurs when a process is already running on the port you’re trying to use. All you need to do is kill that process. In this case, since the port we want to use is 3000 we could simply paste and execute the below code in our terminal.

Exit fullscreen mode

This will kill the process running on port 3000 and you should be good to start your server with npm start like usual.

Save this command for future use

If this happens often, it’s a great idea to add an alias to bash for reuse anytime. The below code is a function that accepts a port number to kill and when saved can be reused for any port number.

Exit fullscreen mode

The quick and easy way to save

Simply execute the below command and the killport function will be available every time you open bash. Just remember to restart your terminal for the saved function to be loaded after first adding it.

Exit fullscreen mode

Below is an example of how the newly defined killport function can be used to kill a process on port 3000.

Exit fullscreen mode

The slightly more advanced way to save

To save this function alongside your other bash aliases and configurations you just need to add the below code to

/.bash_aliases which can be accomplished using vim

/.bashrc and pasting in the code snippet.

Источник

Error: listen EADDRINUSE: address already in use . 5000 #1849

Expected behaviour

Close port before reinitializing server.

Actual behaviour

Steps to reproduce

1. Initialize app (basic MERN app)
2. Save any file.
3. Error is thrown.

This only started happening after I updated my Mac to Big Sur. I can circumvent this issue by either stopping the app and killing the port or by saving a second time a couple of seconds after the first crashed the server.

The text was updated successfully, but these errors were encountered:

Can you explain and provide example code? Because I’m pretty sure «basic» actually means: set up mongodb, add nginx, possibly webpack and a bunch others. i.e. not compatible with «basic».

If you can provide code that replicates this issue, happy to look at it. Otherwise this is too vague.

server.js roughly looks like this:

Okay, start striping the code back until you have the bare minimum and you can still replicate, then post that here, then we can take a look.

I’ve recently started facing the same issue on my own application. Nodemon was working fine all this while but now seems to be leaving a single Node process listening on an open port (3000, in my case). I looked up past issues on the GitHub repo and found that the most popular one had been closed last year.

My stripped-down entry file (app.js) looks like this:

As for other environment and version info:

• Node.js: v15.14.0
• Nodemon: 2.0.7
• Express: 4.17.1
• OS: Ubuntu 20.04.2 LTS on Windows 10 (WSL 2)

Right now, I’m forced to manually kill the running process myself and restart the Node server, which defeats the purpose of using Nodemon at all. Any help is appreciated.

I’ve found a temporary work-around, the steps for which are listed below:

1. Install the NPM kill-port package as a development dependency: npm install -D kill-port
2. Create a new file in your project’s root directory called nodemon.json and paste in the following JSON (edit the port numbers below from 3000 to whatever port you’re using for your Node.js app):

1. Add the following NPM script to your package.json file (if you haven’t already):

All credit goes to Tudor Constantin on Stack Overflow. However, it is a bit tedious and definitely a workaround, not something that should be done for all future Node.js projects.

Correction: The method I’ve shown above provides inconsistent results, and shouldn’t be considered a fix. It only works half of the time, and also occasionally crashes when Nodemon restarts.

Back to the drawing board.

I came across variants of this issue many times without ever being able to replicate it deterministically. But on all cases, I have found that.

• Killing the port-process $ on the nodemon events start , restart or crash , does not solve my problem.
• Synchronously killing it right before calling .listen(. ) on my express app does not solve my problem.
• However, asynchronously killing it before calling .listen(. ) in a .then() does solve my problem, when.
  • . either fuser -k $/tcp and npx kill-port $ is used to kill the port-process.
  • . the nodemon restart is delayed (hint: to delay it, merge your current nodemon.json with > ). I have the solution below running almost all of the times with .

I have written a brief code snippet that does the job of killing the conflicting port-process at run-time, using fuser . I don’t think adapting the code so as to use npx kill-port $ would be very hard: I would appreciate if anyone could augment my code with that adaptation 🙂

Basically, one call of killPort keeps killing all the port-processes that hold onto the port $ until no processes are left. Finally, an interval is set so that if a round of killPort has killed any process, it checks again after some time. This killing and re-killing was done because for some reason the conflicting port-processes would get killed once but the error EADDRINUSE would still show up. It may be overkill, pun intended, but to be honest, it works, and I’m happy because of that.

Here it is, along with my current use case and its output:

Источник

Error: listen EADDRINUSE . 3000 #817

[16:15:30] The server is running at http://localhost:3000/
events.js:160
throw er; // Unhandled ‘error’ event
^

Error: listen EADDRINUSE . 3000

I continuously get this error. Even though nothing else is running on port 3000.
I am running Node v 6.4.0 and NPM v 3.10.3

Any idea on how to get this to work?

The text was updated successfully, but these errors were encountered:

@musdy Looks like something may listen on IPv6 port, are you sure that anything is there?
Reopen if you discover that I’m wrong and this is really RSK on node issue

I’m seeing the same issue, running Node v 6.9.1 and NPM v 3.10.8 after a fresh git clone from master.

Run lsof -i :3000 to see what process is using port 3000 and kill it before running npm start .

I did that and I have no processes using port 3000. Seems to be an issue with browser-sync, in particular at module.exports.plugin (/PATH/TO/PROJECT/node_modules/browser-sync/lib/server/index.js:36:25 .

As I said above, my project should be up to date with the current master branch and I haven’t made any local changes.

Here’s the entire error message:

This error comes directly from node core and it means it cannot start listening on this port. Check other applications, security programs etc.

Also check your own tweaks if you didn’t try start server twice in code.

i got this error recently

$ node server.js
[0.165]: 5000 x 5000 room initalized. Max food: 250, max nest food: 17.112765133926963.
[2.987]: Preparing definition export.
[2.993]: Mockups written to /app/src/server/../client/json/mockups.json!
[2.994]: Building client version hash, reading from /app/src/server/../client/js/app.js and /app/src/server/lib/definitions.js.
[3.052]: Placing 37 obstacles!
events.js:160
throw er; // Unhandled ‘error’ event
^
Error: listen EADDRINUSE . 3000
at Object.exports._errnoException (util.js:1020:11)
at exports._exceptionWithHostPort (util.js:1043:20)
at Server._listen2 (net.js:1277:14)
at listen (net.js:1313:10)
at Server.listen (net.js:1409:5)
at websockets (/app/src/server/server.js:5356:16)
at Object. (/app/src/server/server.js:5365:3)
at Module._compile (module.js:577:32)
at Object.Module._extensions..js (module.js:586:10)
at Module.load (module.js:494:32)

i fixed it by putting // and undo it but now it didnt work after ity has restart

Something is using port 3000 (Check if you stop previous instance, check if you are not trying instantiate server twice).
Only you are responsible for your machine

You should check whether your 3000 port is currently used. it then you should kill than process.

Источник

Node.js v19.4.0 documentation

Errors #

Applications running in Node.js will generally experience four categories of errors:

• Standard JavaScript errors such as , , , , , and .
• 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 the node:assert module.

All JavaScript and system errors raised by Node.js inherit from, or are instances of, the standard JavaScript 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.

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 an Error object passed as the first argument to that function. If that first argument is not null and is an instance of Error , then an error occurred that should be handled.

When an asynchronous method is called on an object that is an EventEmitter , errors can be routed to that object’s ‘error’ event.

A handful of typically asynchronous methods in the Node.js API may still use the throw mechanism to raise exceptions that must be handled using try…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.

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 .

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 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 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[, options]) #

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 String(message) . If the cause option is provided, it is assigned to the error.cause property. 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]) #

Creates a .stack property on targetObject , which when accessed returns a string representing the location in the code at which Error.captureStackTrace() was called.

The first line of the trace will be prefixed with $: $ .

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 the user. For instance:

Error.stackTraceLimit #

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.cause #

If present, the error.cause property is the underlying cause of the Error . It is used when catching an error and throwing a new one with a different message or code in order to still have access to the original error.

The error.cause property is typically set by calling new Error(message, < cause >) . It is not set by the constructor if the cause option is not provided.

This property allows errors to be chained. When serializing Error objects, util.inspect() recursively serializes error.cause if it is set.

error.code #

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 #

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).

error.stack #

The error.stack property is a string describing the point in the code at which the Error was instantiated.

The first line is formatted as : , 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:

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 (using CommonJS module system), or its dependencies.
• :///url/to/module/file.mjs:line:column , if the frame represents a call in a user program (using ES module system), 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 #

Indicates the failure of an assertion. For details, see Class: assert.AssertionError .

Class: RangeError #

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.

Node.js will generate and throw RangeError instances immediately as a form of argument validation.

Class: ReferenceError #

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.

Unless an application is dynamically generating and running code, ReferenceError instances indicate a bug in the code or its dependencies.

Class: SyntaxError #

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.

SyntaxError instances are unrecoverable in the context that created them – they may only be caught by other contexts.

Class: SystemError #

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 If present, the address to which a network connection failed
• code The string error code
• dest If present, the file path destination when reporting a file system error
• errno The system-provided error number
• info If present, extra details about the error condition
• message A system-provided human-readable description of the error
• path If present, the file path when reporting a file system error
• port If present, the network connection port that is not available
• syscall The name of the system call that triggered the error

error.address #

If present, error.address is a string describing the address to which a network connection failed.

error.code #

The error.code property is a string representing the error code.

error.dest #

If present, error.dest is the file path destination when reporting a file system error.

error.errno #

The error.errno property is a negative number which corresponds to the error code defined in libuv Error handling .

On Windows the error number provided by the system will be normalized by libuv.

To get the string representation of the error code, use util.getSystemErrorName(error.errno) .

error.info #

If present, error.info is an object with details about the error condition.

error.message #

error.message is a system-provided human-readable description of the error.

error.path #

If present, error.path is a string containing a relevant invalid pathname.

error.port #

If present, error.port is the network connection port that is not available.

error.syscall #

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 , or https ) 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 the http and net 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, run ulimit -n 2048 in the same shell that will run the Node.js process.

ENOENT (No such file or directory): Commonly raised by fs 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 by fs.readdir .

ENOTEMPTY (Directory not empty): A directory with entries was the target of an operation that requires an empty directory, usually fs.unlink .

ENOTFOUND (DNS lookup failed): Indicates a DNS failure of either EAI_NODATA or EAI_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 the net and http 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 by http or net . Often a sign that a socket.end() was not properly called.

Class: TypeError #

Indicates that a provided argument is not an allowable type. For example, passing a function to a parameter which expects a string would be a TypeError .

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 #

ABORT_ERR #

Used when an operation has been aborted (typically using an AbortController ).

APIs not using AbortSignal s typically do not raise an error with this code.

This code does not use the regular ERR_* convention Node.js errors use in order to be compatible with the web platform’s AbortError .

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 node: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 node:assert module.

ERR_ASSERT_SNAPSHOT_NOT_SUPPORTED #

An attempt was made to use assert.snapshot() in an environment that does not support snapshots, such as the REPL, or when using node —eval .

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_CLOSED_MESSAGE_PORT #

There was an attempt to use a MessagePort instance in a closed state, usually after .close() has been called.

ERR_CONSOLE_WRITABLE_STREAM #

Console was instantiated without stdout stream, or Console has a non-writable stdout or stderr stream.

ERR_CONSTRUCT_CALL_INVALID #

A class constructor was called that is not callable.

ERR_CONSTRUCT_CALL_REQUIRED #

A constructor for a class was called without new .

ERR_CONTEXT_NOT_INITIALIZED #

The vm context passed into the API is not yet initialized. This could happen when an error occurs (and is caught) during the creation of the context, for example, when the allocation fails or the maximum call stack size is reached when the context is created.

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(‘node: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 node: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_INITIALIZATION_FAILED #

Initialization of the crypto subsystem failed.

ERR_CRYPTO_INVALID_AUTH_TAG #

An invalid authentication tag was provided.

ERR_CRYPTO_INVALID_COUNTER #

An invalid counter was provided for a counter-mode cipher.

ERR_CRYPTO_INVALID_CURVE #

An invalid elliptic-curve was provided.

ERR_CRYPTO_INVALID_DIGEST #

An invalid crypto digest algorithm was specified.

ERR_CRYPTO_INVALID_IV #

An invalid initialization vector was provided.

ERR_CRYPTO_INVALID_JWK #

An invalid JSON Web Key was provided.

ERR_CRYPTO_INVALID_KEY_OBJECT_TYPE #

The given crypto key object’s type is invalid for the attempted operation.

ERR_CRYPTO_INVALID_KEYLEN #

An invalid key length was provided.

ERR_CRYPTO_INVALID_KEYPAIR #

An invalid key pair was provided.

ERR_CRYPTO_INVALID_KEYTYPE #

An invalid key type was provided.

ERR_CRYPTO_INVALID_MESSAGELEN #

An invalid message length was provided.

ERR_CRYPTO_INVALID_SCRYPT_PARAMS #

Invalid scrypt algorithm parameters were provided.

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_INVALID_TAG_LENGTH #

An invalid authentication tag length was provided.

ERR_CRYPTO_JOB_INIT_FAILED #

Initialization of an asynchronous crypto operation failed.

ERR_CRYPTO_JWK_UNSUPPORTED_CURVE #

Key’s Elliptic Curve is not registered for use in the JSON Web Key Elliptic Curve Registry.

ERR_CRYPTO_JWK_UNSUPPORTED_KEY_TYPE #

Key’s Asymmetric Key Type is not registered for use in the JSON Web Key Types Registry.

ERR_CRYPTO_OPERATION_FAILED #

A crypto operation failed for an otherwise unspecified reason.

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_CRYPTO_UNSUPPORTED_OPERATION #

An attempt to invoke an unsupported crypto operation was made.

ERR_DEBUGGER_ERROR #

An error occurred with the debugger.

ERR_DEBUGGER_STARTUP_ERROR #

The debugger timed out waiting for the required host/port to be free.

ERR_DLOPEN_DISABLED #

Loading native addons has been disabled using —no-addons .

ERR_DLOPEN_FAILED #

A call to process.dlopen() failed.

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 node: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 node: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 node:domain module had been loaded.

ERR_DUPLICATE_STARTUP_SNAPSHOT_MAIN_FUNCTION #

v8.startupSnapshot.setDeserializeMainFunction() could not be called because it had already been called before.

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_EVAL_ESM_CANNOT_PRINT #

—print cannot be used with ESM input.

ERR_EVENT_RECURSION #

Thrown when an attempt is made to recursively dispatch an event on EventTarget .

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_FEATURE_UNAVAILABLE_ON_PLATFORM #

Used when a feature that is not available to the current platform which is running Node.js is used.

ERR_FS_CP_DIR_TO_NON_DIR #

An attempt was made to copy a directory to a non-directory (file, symlink, etc.) using fs.cp() .

ERR_FS_CP_EEXIST #

An attempt was made to copy over a file that already existed with fs.cp() , with the force and errorOnExist set to true .

ERR_FS_CP_EINVAL #

When using fs.cp() , src or dest pointed to an invalid path.

ERR_HTTP_CONTENT_LENGTH_MISMATCH #

Response body size doesn’t match with the specified content-length header value.

ERR_FS_CP_FIFO_PIPE #

An attempt was made to copy a named pipe with fs.cp() .

ERR_FS_CP_NON_DIR_TO_DIR #

An attempt was made to copy a non-directory (file, symlink, etc.) to a directory using fs.cp() .

ERR_FS_CP_SOCKET #

An attempt was made to copy to a socket with fs.cp() .

ERR_FS_CP_SYMLINK_TO_SUBDIRECTORY #

When using fs.cp() , a symlink in dest pointed to a subdirectory of src .

ERR_FS_CP_UNKNOWN #

An attempt was made to copy to an unknown file type with fs.cp() .

ERR_FS_EISDIR #

Path is a directory.

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.

An attempt was made to add more headers after the headers had already been sent.

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_REQUEST_TIMEOUT #

The client has not sent the entire request within the allowed time.

ERR_HTTP_SOCKET_ENCODING #

Changing the socket encoding is not allowed per RFC 7230 Section 3.

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.

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.

Multiple values were provided for an HTTP/2 header field that was required to have only a single value.

An additional headers was specified after an HTTP/2 response was initiated.

An attempt was made to send multiple response headers.

ERR_HTTP2_INFO_STATUS_NOT_ALLOWED #

Informational HTTP status codes ( 1xx ) may not be set as the response status code on HTTP/2 responses.

HTTP/1 connection specific headers are forbidden to be used in HTTP/2 requests and responses.

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.

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_MEM #

Out of memory when using the http2session.setLocalWindowSize(windowSize) API.

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.

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_TOO_MANY_INVALID_FRAMES #

The limit of acceptable invalid HTTP/2 protocol frames sent by the peer, as specified through the maxSessionInvalidFrames option, has been exceeded.

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_ILLEGAL_CONSTRUCTOR #

An attempt was made to construct an object using a non-public constructor.

ERR_IMPORT_ASSERTION_TYPE_FAILED #

An import assertion has failed, preventing the specified module to be imported.

ERR_IMPORT_ASSERTION_TYPE_MISSING #

An import assertion is missing, preventing the specified module to be imported.

ERR_IMPORT_ASSERTION_TYPE_UNSUPPORTED #

An import assertion is not supported by this version of Node.js.

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 #

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_ACTIVATED #

While using the node:inspector module, an attempt was made to activate the inspector when it already started to listen on a port. Use inspector.close() before activating it on a different address.

ERR_INSPECTOR_ALREADY_CONNECTED #

While using the node:inspector module, an attempt was made to connect when the inspector was already connected.

ERR_INSPECTOR_CLOSED #

While using the node: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 node:inspector module.

ERR_INSPECTOR_NOT_ACTIVE #

The inspector is not active when inspector.waitForDebugger() is called.

ERR_INSPECTOR_NOT_AVAILABLE #

The node:inspector module is not available for use.

ERR_INSPECTOR_NOT_CONNECTED #

While using the node: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_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_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_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_MIME_SYNTAX #

The syntax of a MIME is not valid.

ERR_INVALID_MODULE #

An attempt was made to load a module that does not exist or was otherwise not valid.

ERR_INVALID_MODULE_SPECIFIER #

The imported module string is an invalid URL, package name, or package subpath specifier.

ERR_INVALID_OBJECT_DEFINE_PROPERTY #

An error occurred while setting an invalid attribute on the property of an object.

ERR_INVALID_PACKAGE_CONFIG #

An invalid package.json file 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 . The conditions under which this error is used are described in the REPL 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_STATE #

Indicates that an operation cannot be completed due to an invalid state. For instance, an object may have already been destroyed, or may be performing another operation.

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.

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 or the legacy url.parse() 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_LOADER_CHAIN_INCOMPLETE #

An ESM loader hook returned without calling next() and without explicitly signaling a short circuit.

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_INVALID_SPECIFIER #

A policy manifest resource had an invalid value for one of its dependency mappings. Update the manifest entry to match 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_MESSAGE_TARGET_CONTEXT_UNAVAILABLE #

A message posted to a MessagePort could not be deserialized in the target vm Context . Not all Node.js objects can be successfully instantiated in any context at this time, and attempting to transfer them using postMessage() can fail on the receiving side in that case.

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_OPTION #

For APIs that accept options objects, some options might be mandatory. This code is thrown if a required option is missing.

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_MISSING_TRANSFERABLE_IN_TRANSFER_LIST #

An object that needs to be explicitly listed in the transferList argument is in the object passed to a postMessage() call, but is not provided in the transferList for that call. Usually, this is a MessagePort .

In Node.js versions prior to v15.0.0, the error code being used here was ERR_MISSING_MESSAGE_PORT_IN_TRANSFER_LIST . However, the set of transferable object types has been expanded to cover more types than MessagePort .

ERR_MODULE_NOT_FOUND #

A module file could not be resolved by the ECMAScript modules loader while attempting an import operation or when loading the program entry point.

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 Node-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_NOT_BUILDING_SNAPSHOT #

An attempt was made to use operations that can only be used when building V8 startup snapshot even though Node.js isn’t building one.

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_IMPORT_NOT_DEFINED #

The package.json «imports» field does not define the given internal package specifier mapping.

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_PARSE_ARGS_INVALID_OPTION_VALUE #

When strict set to true , thrown by util.parseArgs() if a value is provided for an option of type , or if a value is provided for an option of type .

ERR_PARSE_ARGS_UNEXPECTED_POSITIONAL #

Thrown by util.parseArgs() , when a positional argument is provided and allowPositionals is set to false .

ERR_PARSE_ARGS_UNKNOWN_OPTION #

When strict set to true , thrown by util.parseArgs() if an argument is not configured in options .

ERR_PERFORMANCE_INVALID_TIMESTAMP #

An invalid timestamp value was provided for a performance mark or measure.

ERR_PERFORMANCE_MEASURE_INVALID_OPTIONS #

Invalid options were provided for a performance measure.

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 #

An attempt was made to require() an ES Module.

ERR_SCRIPT_EXECUTION_INTERRUPTED #

Script execution was interrupted by SIGINT (For example, 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 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_CLOSED #

An attempt was made to operate on an already closed socket.

ERR_SOCKET_CLOSED_BEFORE_CONNECTION #

When calling net.Socket.write() on a connecting socket and the socket was closed before the connection was established.

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_ALREADY_FINISHED #

A stream method was called that cannot complete because the stream was finished.

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 .

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_TAP_LEXER_ERROR #

An error representing a failing lexer state.

ERR_TAP_PARSER_ERROR #

An error representing a failing parser state. Additional information about the token causing the error is available via the cause property.

ERR_TAP_VALIDATION_ERROR #

This error represents a failed TAP validation.

ERR_TEST_FAILURE #

This error represents a failed test. Additional information about the failure is available via the cause property. The failureType property specifies what the test was doing when the failure occurred.

ERR_TLS_CERT_ALTNAME_FORMAT #

This error is thrown by checkServerIdentity if a user-supplied subjectaltname property violates encoding rules. Certificate objects produced by Node.js itself always comply with encoding rules and will never cause this error.

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_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_INVALID_STATE #

The TLS socket must be connected and securely established. Ensure the ‘secure’ event is emitted before continuing.

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_PSK_SET_IDENTIY_HINT_FAILED #

Failed to set PSK identity hint. Hint may be too long.

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_TRACE_EVENTS_CATEGORY_REQUIRED #

The trace_events.createTracing() method requires at least one trace event category.

ERR_TRACE_EVENTS_UNAVAILABLE #

The node:trace_events module could not be loaded because Node.js was compiled with the —without-v8-platform flag.

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_UNAVAILABLE_DURING_EXIT #

Function was called within a process.on(‘exit’) handler that shouldn’t be called within process.on(‘exit’) handler.

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 #

An attempt was made to load a module with an unknown or unsupported file extension.

ERR_UNKNOWN_MODULE_FORMAT #

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, self-reference a package using its name and define a custom subpath in the «exports» field of the package.json file.

ERR_UNSUPPORTED_ESM_URL_SCHEME #

import with URL schemes other than file and data is unsupported.

ERR_USE_AFTER_CLOSE #

An attempt was made to use something that was already closed.

ERR_VALID_PERFORMANCE_ENTRY_TYPE #

While using the Performance Timing API ( perf_hooks ), no valid performance entry types are 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_LINK_FAILURE #

The module was unable to be linked due to a failure.

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_WEBASSEMBLY_RESPONSE #

The Response that has been passed to WebAssembly.compileStreaming or to WebAssembly.instantiateStreaming is not a valid WebAssembly response.

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_OPERATION #

The requested functionality is not supported in worker threads.

ERR_ZLIB_INITIALIZATION_FAILED #

Creation of a zlib object failed due to incorrect configuration.

History

Max header size in http_parser was set to 8 KiB.

Too much HTTP header data was received. In order to protect against malicious or malconfigured clients, if more than 8 KiB 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.

HPE_UNEXPECTED_CONTENT_LENGTH #

Server is sending both a Content-Length header and Transfer-Encoding: chunked .

Transfer-Encoding: chunked allows the server to maintain an HTTP persistent connection for dynamically generated content. In this case, the Content-Length HTTP header cannot be used.

Use Content-Length or Transfer-Encoding: chunked .

MODULE_NOT_FOUND #

History

Added requireStack property.

A module file could not be resolved by the CommonJS modules loader while attempting a require() operation or when loading the program entry point.

Legacy Node.js error codes #

ERR_CANNOT_TRANSFER_OBJECT #

The value passed to postMessage() contained an object that is not supported for transferring.

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.

Used when an HTTP/2 Headers Object is expected.

Used when a required header is missing in an HTTP/2 message.

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_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_MISSING_MESSAGE_PORT_IN_TRANSFER_LIST #

This error code was replaced by ERR_MISSING_TRANSFERABLE_IN_TRANSFER_LIST in Node.js v15.0.0, because it is no longer accurate as other types of transferable objects also exist now.

ERR_NAPI_CONS_PROTOTYPE_OBJECT #

Used by the Node-API when Constructor.prototype is not an object.

ERR_NETWORK_IMPORT_BAD_RESPONSE #

Response was received but was invalid when importing a module over the network.

ERR_NETWORK_IMPORT_DISALLOWED #

A network module attempted to load another module that it is not allowed to load. Likely this restriction is for security reasons.

ERR_NO_LONGER_SUPPORTED #

A Node.js API was called in an unsupported manner, such as Buffer.write(string, encoding, offset[, length]) .

ERR_OPERATION_FAILED #

An operation failed. This is typically used to signal the general failure of an asynchronous operation.

ERR_OUTOFMEMORY #

Used generically to identify that an operation caused an out of memory condition.

ERR_PARSE_HISTORY_DATA #

The node:repl module was unable to parse data from the REPL history file.

ERR_SOCKET_CANNOT_SEND #

Data could not be sent on a socket.

ERR_STDERR_CLOSE #

History

Rather than emitting an error, process.stderr.end() now only closes the stream side but not the underlying resource, making this error obsolete.

Removed in: v10.12.0

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 #

History

Rather than emitting an error, process.stderr.end() now only closes the stream side but not the underlying resource, making this error obsolete.

Removed in: v10.12.0

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_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_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_V8BREAKITERATOR #

The V8 BreakIterator API was used but the full ICU data set is not installed.

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_VM_MODULE_LINKING_ERRORED #

The linker function returned a module for which linking has failed.

ERR_WORKER_UNSUPPORTED_EXTENSION #

The pathname used for the main script of a worker has an unknown file extension.

ERR_ZLIB_BINDING_CLOSED #

Used when an attempt is made to use a zlib object after it has already been closed.

Источник

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Вопрос:

express -e folderName
npm install ejs --save
npm install

events.js:72
throw er; // Unhandled 'error' event
^
Error: listen EADDRINUSE
at errnoException (net.js:884:11)
at Server._listen2 (net.js:1022:14)
at listen (net.js:1044:10)
at Server.listen (net.js:1110:5)
at Object.<anonymous> (folderName/app.js:33:24)
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)

Лучший ответ:

netstat -tulnp | grep <port no>

Ответ №1

ps aux | awk '/node/{print $2}' | xargs kill -9

Ответ №2

killall node

Ответ №3

nodejs /path/to/script.js

sudo nodejs /path/to/script.js

Ответ №4

ps -e

sudo killall -9 node

Ответ №5

app.set('port', process.env.PORT || 3000);<br>

app.set('port', process.env.PORT || 8080);<br>

Ответ №6

Используемый порт Node может быть использован другой программой. В моем случае это было ntop, которое я недавно установил. Мне пришлось открыть http://localhost:3000/ в браузере, чтобы реализовать его. Другой способ найти этот процесс – здесь.

Ответ №7

Если вы хотите использовать тот же номер порта, введите kill % в терминал, который убивает текущий фоновый процесс и освобождает порт для дальнейшего использования.

Ответ №8

sudo pkill node

Ответ №9

Закройте все остальные серверы node, которые запущены, даже если они находятся в других терминальных окнах или работают на разных портах. Это должно решить проблему.

Ответ №10

app.set('port', process.env.PORT || 3000);

Ответ №11

Ответ №12

COMMAND   PID  USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
node    16615 aegon   13u  IPv6 183768      0t0  TCP *:3000 (LISTEN)

Ответ №13

В моем случае мне пришлось запустить vagrant reload. Даже без процессов node, выполняющих мое экспресс-приложение на моей виртуальной машине, я все еще получал эту ошибку до перезагрузки брандмауэра.

Ответ №14

sudo service NAMEOFSERVICE stop

Ответ №15

Ответ №16

Ответ №17

Вы также можете изменить порт из Gruntfile.js и снова запустить.

Ответ №18

MongoClient.connect(db.url, (err, database) => {
if (err) return console.log(err);
require('./app/routes')(app, database);

app.listen(port, () => {
console.log('We are live on ' + port);
});
});

require('./app/routes')(app, {});
app.listen(port, () => {
console.log("We are live on " + port);
});

MongoClient.connect(db.url, (err, database) => {
if (err) return console.log(err);
require('./app/routes')(app, database);

app.listen(port, () => {
console.log('We are live on ' + port);
});
});

require('./app/routes')(app, {});

Ответ №19

У меня была та же проблема, и я узнал, что процесс nodejs, который я ранее отменил с помощью CTRL + C, все еще работает. Проблема в Windows 10 заключается в том, что Ctrl + C не убивает изящно nodejs. Я открыл диспетчер задач и убил процесс вручную. Решения, представленные на GitHub, не спомогли мне.

Ответ №20

Если вы используете Windows, то вы можете завершить процесс из диспетчера задач для node.js

Ответ №21

npm install ws@3.3.2 --save-dev --save-exact

Ответ №22

Ответ №23

process.on('SIGINT', function() {
console.log( "nGracefully shutting down from SIGINT (Ctrl-C)" );
// some other closing procedures go here
process.exit(1);
});

Ответ №24

lsof -i @localhost:8080

Ответ №25

Просто проверьте свой объект в коде Visual Studio. Поскольку я запускал свое приложение для узлов и я переводил компьютер в спящий режим, то на следующее утро я снова включил свой ноутбук в разработку программного обеспечения. Затем я снова запускаю команду nodemon app.js. Первый waa запускается с ночи, а второй запускает мою последнюю команду, поэтому две командные подсказки прослушивают одни и те же порты, поэтому вы получаете эту проблему. Просто закройте один терминал или все терминалы, затем запустите ваш узел app.js или nodemon app.js

Ответ №26

Ответ №27

Просто измените свой порт, возможно, ваш текущий порт используется iis или каким-либо другим сервером.

Ответ №28

Ответ №29

npm install –save –save -точная реакция-scripts@2.1.