express-error-catcher

express-error-catcher is a robust npm package engineered to streamline error handling in Node.js Express applications. It provides an elegant solution for managing async/await errors, reducing boilerplate code, and enhancing the maintainability of your applications.

Key Features

- Automated Error Handling: Effortlessly catch and handle errors in asynchronous route handlers, allowing for cleaner and more concise code.
- Customizable Middleware: Easily configure default error messages, status codes, and logging preferences to suit your development and production environments.
- Multiple Logging Formats: Choose between detailed development logs and minimal production logs to meet your specific needs.
- Improved Code Readability: Eliminate redundant try-catch blocks, making your codebase more readable and easier to maintain.

Installation

Integrating express-error-catcher into your project is straightforward. Use the following npm command to install the package:

``bash
npm install express-error-catcher
`

Usage Overview

To leverage express-error-catcher in your Express application, follow these steps:

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Begin by importing the necessary functions and middleware from the express-error-catcher package.

`js
import express from "express";
import { asyncErrorHandler, error, Response, Error } from "express-error-catcher";
`

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Apply the error-handling middleware with optional configuration parameters to customize its behavior.

`js
const app = express();

app.use(error({
defaultErrorMessage: "Internal server error", // Sets a default error message for uncaught errors.
defaultStatusCode: 500, // Defines the default HTTP status code for errors.
log: "dev" // Chooses the logging format: "dev" for detailed logs, "prod" for concise logs.
}));
`

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Use the asyncErrorHandler function to wrap your asynchronous route handlers. This ensures that any errors are automatically caught and passed to the error-handling middleware.

`js
app.get(
"/name",
asyncErrorHandler((req, res) => {
// Intentionally throwing an error
throw Error("Error while retrieving name", 500);

// Returning a successful response
return Response("Successfully retrieved name", { name: "Daisy" }, 200);
})
);
`

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Finally, start your Express server as usual:

`js
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
console.log(Server is running on port ${PORT});
});
`

Detailed Configuration Options

The error middleware provides a range of configuration options to tailor error handling to your application’s requirements.

- defaultErrorMessage: A string specifying the default message to return when an error is unhandled.
- defaultStatusCode: An integer representing the default HTTP status code to use when responding to unhandled errors.
- log: A string determining the log format. Options include:
- "dev": Detailed log output for development, including error messages and file paths.
- "pretty": A more readable format compared to dev, with enhanced formatting for better human readability. Example.
- "production": Simplified log output for production environments, focusing on error messages only.

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#### Development (dev)

In development mode, express-error-catcher provides detailed logs that include the error message, file path, and line number, presented in a table format for easy reading:

`plaintext
<------------------------------->
ERROR => Internal Server Error
FILE => /path/to/file.js:16:11
<------------------------------->
`

#### Pretty (pretty)

In development mode, express-error-catcher offers detailed logs in a table format that includes the error message and file path. This format enhances readability and helps quickly identify issues:

`plaintext
┌─────────┬─────────────────────────┬────────────────────────────────┐
│ (index) │ Message │ File │
├─────────┼─────────────────────────┼────────────────────────────────┤
│ 0 │ 'Internal Server Error' │ '/path/to/file.js:16:11' │
└─────────┴─────────────────────────┴────────────────────────────────┘
`

#### Production (production)

In production mode, logs are minimized to reduce noise and focus on essential information:

`plaintext
<------------------------------->
ERROR => Internal Server Error
<------------------------------->
`

Advanced Use Cases

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express-error-catcher allows you to define and handle custom errors with specific messages and status codes, providing fine-grained control over error management.

`js
throw Error("Custom error message", 400);
`

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#### Success Response
When an operation completes successfully, the response is structured as follows:


`js
return new Response("Success.", { data: "Welcome daisy.." }, 200);
`
The corresponding JSON output will be:

`json
{
"code": 200,
"success": true,
"status": "OK",
"message": "Success.",
"data": "Welcome daisy.."
}
`

#### Error Response
If an error occurs during processing, an error is thrown with the following structure:

`js
throw new Error("Daisy already exists.", 400);
`
The corresponding JSON output will be:
`json
{
"success": false,
"code": 400,
"status": "Bad Request",
"message": "Daisy already exists."
}
`
#### Error Response with Additional Data
You can also include additional data in the error response for more context:

`js
throw new Error("Daisy already exists.", 400, { details: "Validation failed" });
`

`json
{
"success": false,
"code": 400,
"status": "Bad Request",
"message": "Daisy already exists.",
"data": {
"details": "Validation failed"
}
}
``

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The package is designed to integrate seamlessly with other Express middleware, allowing you to create a cohesive error-handling strategy across your application.