Prisma Better Errors

This module provides a way to handle errors thrown by the Prisma ORM in a more descriptive way. By default, Prisma throws errors with error codes that can be hard to understand for developers not familiar with the specific error codes used by Prisma. This module maps Prisma error codes to error messages and HTTP status codes, making it easier for developers to understand what went wrong and return appropriate error responses in their APIs.

Installation

You can install this module using npm:

npm install prisma-better-errors

Usage

To use this module, you need to import the prismaError class and use it to catch Prisma errors in your code. Here's an example:

import { PrismaClient,Prisma } from '@prisma/client';
import {  prismaError } from './prisma';

const prisma = new PrismaClient();

async function main() {
  try {
    const user = await prisma.user.create({
      data: {
        name: 'Alice',
        email: 'alice@prisma.io',
      },
    });
    console.log(user);
  } catch (error:any) {
    if (error instanceof Prisma.PrismaClientKnownRequestError) {
      console.log('HERE');
      throw new prismaError(error);
    }
    throw error
  }
}

main()
  .then(async () => {
    await prisma.$disconnect();
  })
  .catch(async (e) => {
    console.error(e);
    await prisma.$disconnect();
    process.exit(1);
  });
}

In this example, the getUser function tries to fetch a user from the database using Prisma's findUnique method. If an error is thrown, the prismaError class is used to wrap the error and provide a more descriptive error message and HTTP status code.

The prismaError class extends the built-in Error class and adds three properties:

message: the error message.
statusCode: the HTTP status code to return in the API response.
metaData (optional): an object containing additional metadata about the error. This can be useful for debugging purposes.

With express middleware

Add the prismaError class to your error handling middleware and return the statusCode and title properties as part of the API error response. The metaData property can also be returned if it contains any additional information about the error.

app.use((err, req, res, next) => {
  if (err instanceof prismaError) {
    res.status(err.statusCode).json({
      title: err.title,
      message: err.message,
      metaData: err.metaData,
    });
  } else {
    // Handle other errors here
  }
});

// response
{
    "title": "Prisma Error",
    "statusCode": 409,
    "message": "Unique constraint failed",
    "metaData": {
        "target": [
            "email"
        ]
    }
}

Custom Error Messages

You can customize the error message and HTTP status code for each Prisma error code by modifying the QueryError map in the prisma-better-errors module. For example:

import { QueryError, prismaError } from 'prisma-better-errors';

// Add a new error code mapping
QueryError.set('P3000', { message: 'My custom error message', httpStatus: 422 });

// Use the new error code in your code
try {
  // Prisma code here
} catch (error) {
  // these are the query errors
  if (error instanceof Prisma.PrismaClientKnownRequestError) {
    throw new prismaError(error);
  }
}

Error Codes

The following table lists the error codes and their corresponding error messages and HTTP status codes:

Error Code	Message	HTTP Status Code
P2000	The provided value for the column is too long for the column's type	400
P2001	The record searched for in the where condition does not exist	404
P2002	Unique constraint failed	409
P2003	Foreign key constraint failed	409
P2004	A constraint failed on the database	400
P2005	The value stored in the database for the field is invalid for the field's type	400
P2006	The provided value for the field is not valid	400
P2007	Data validation error	400
P2008	Failed to parse the query	400
P2009	Failed to validate the query	400
P2010	Raw query failed	500
P2011	Null constraint violation	400
P2012	Missing a required value	400
P2013	Missing a required argument	400
P2014	The change you are trying to make would violate the required relation	400
P2015	A related record could not be found	404
P2016	Query interpretation error	400
P2017	The records for relation between the parent and child models are not connected	400
P2018	The required connected records were not found	404
P2019	Input error	400
P2020	Value out of range for the type	400
P2021	The table does not exist in the current database	404
P2022	The column does not exist in the current database	404
P2023	Inconsistent column data	400
P2024	Timed out fetching a new connection from the pool	500
P2025	An operation failed because it depends on one or more records that were required but not found	404
P2026	The current database provider doesn't support a feature that the query used	400
P2027	Multiple errors occurred on the database during query execution	500

Author

Youssef Hany

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