hint-errors

JavaScript errors done right

Install

npm install hint-errors

Usage

Standalone scripts

Add one line to the top of your entry file. The package catches the first uncaught error, shows a hint, and exits.

require("hint-errors");

const a = 10;
a = 20; // TypeError: Assignment to constant variable

When the error is fixed, the script continues normally.

Web servers

For long‑running processes, use server mode. The process stays alive after an error so a single bad request doesn't take down the whole server.

require("hint-errors/server");

const http = require("http");

const server = http.createServer((req, res) => {
  if (req.url === "/crash") {
    const user = undefined;
    console.log(user.name); // shown but server keeps running
  }
  res.end("ok");
});

server.listen(3000);

What's covered

JavaScript errors

• TypeError – when a value is not of the expected type (e.g., reading a property of undefined)
• ReferenceError – when a variable that doesn't exist (or hasn't been initialized) is referenced
• SyntaxError – when the code contains invalid JavaScript syntax
• RangeError – when a numeric value is outside the allowed range
• URIError – when a global URI handling function is used incorrectly
• AssertionError – when an assertion from the node:assert module fails

Node.js & OS errors

• ENOENT – file or directory not found
• EACCES – permission denied when accessing a file
• EPERM – operation not permitted, common on Windows
• EEXIST – file already exists
• EISDIR – expected a file, got a directory
• ENOTDIR – expected a directory, got a file
• ENOTEMPTY – directory still has contents
• EMFILE – too many files open at once
• MODULE_NOT_FOUND – package not installed or path is wrong
• ECONNREFUSED – target server isn't running
• ECONNRESET – connection dropped by remote host
• ETIMEDOUT – server didn't respond in time
• EADDRINUSE – port is already taken
• EADDRNOTAVAIL – address not available on this machine
• EPIPE – writing to an already-closed connection
• EAI_AGAIN – DNS lookup failed (temporary failure)
• EHOSTUNREACH – no route to the target host

Async scenarios

• Promise rejected with no .catch()
• Unhandled rejection inside async/await
• Missing await causing undefined reads

Maintainers

• ZLouisMiguel