Allow handler error with an express middleware

[adriexnet]

Allow handler error with an express middleware

What does this PR do?

Allow using an express middleware as handler error

How should this be tested?

• Configure graphqlHTTP with handleErrorWithExpress

app.use('/graph', graphqlHTTP(async (req) => {
  return {
    graphiql: true,
    schema,
    handleErrorWithExpress: true,
    formatError(error) {
      logger.error(error.message, {
        path: error.path,
        locations: error.locations,
        stack: error.stack ? error.stack.split('\n') : [],
        trace: error.trace,
      });
      return {
        message: error.message,
        status: 400,
      };
    }
  };
}));

• Add an error middleware

app.use((error, req, res, next) => {
  if (res.headersSent) {
    return next(error);
  }

  return res.status(error.status || 500).send({
    error: error.message
  });
});

[mitodrummer]

Any idea when this will be merged and released to npm?

[ValfarDeveloper]

Oh man this is so useful! It's a shame that yet is not implemented.

[jsonmaur]

I'd say we should return all the errors in the array, not just the first one.

[augustohsalla]

for god sake, accept this!

[driescroons]

@aagtt @jsonmaur

I wouldn't add the ability to add error middleware to the package itself. I've handled it like so:

• I use express-async-errors (https://www.npmjs.com/package/express-async-errors)
• I throw the error in my customFormatErrorFn
• My error middleware catches the error and is able to handle it according to the type

Here a demo:
https://streamable.com/hvtjg3