I am trying to send a custom error message in JSON format from my express app, which is served in a lambda function using serverless-http
To achieve this, it seems I need to utilize LAMBDA_PROXY APIG integration to enable sending custom error messages directly from a lambda function.
Here's what I have attempted so far:
res.status(400).json({ message: 'email already taken' });
In the serverless.yml file, I have configured the following:
functions:
auth:
handler: src/express/auth/index.handler
name: ${self:service}-auth-${env:STAGE}
# warmup: true
integration: lambda-proxy
memorySize: 128
timeout: 15
events:
- http:
path: /auth/
method: ANY
cors: true
- http:
path: /auth/{any+}
method: ANY
cors: true
This is the response returned by the API (with status code 400):
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Error</title>
</head>
<body>
<pre>Bad Request</pre>
</body>
</html>
Can anyone provide guidance on how I can send a custom response in JSON format?
Update:
After further testing, I noticed that calling next(error) does not trigger the last error handler
const register = async (req, res, next) {
try {
await verifyEmail(req.body.email);
const user = await Users.register(req.body);
const token = sign(user.attrs, {});
res.json({ token, user });
} catch (e) {
next(e);
}
};
const generalError = async (err, req, res, next) => {
// This part is not reached! :(
console.log('generalError handler', JSON.stringify(err));
res.status(errorOut.status).json(errorOut);
};
ApiRouter.post('/register', register);
app.use('/auth', ApiRouter);
app.use(generalError);