Loopback 3 discards error information on multiple validation errors, turning 422 to 500, how can I solve that? - node.js

Question

I'm migrating from Loopback 2 tot 3.
I currently have an issue with validation errors and strong-error-handler
When I post a bulk create which results in multiple validation errors, those get returned as an array of ValidationErrors.
Those errors get grouped by strong-error handler in a 500 internal server error, which is how it was before, but the details of the errors get discarded, when debug is set to false.
In my example I upload an array of tags, but for each tag, a uniqueness validation is executed. When 2 or more tags are already in the database, I have an array of errors, instead of a single validation error
I need a way to determine why the validation failed on the client side, but the details of the errors are discarded now.
Am I doing something wrong here, or should this be considered as a bug?

Answer 1

From the strongloop error handler documentation in loopback,
In production mode, strong-error-handler omits details from error responses to prevent leaking sensitive information:
More information
For 5xx errors, the output contains only the status code and the status name from the HTTP specification.
For 4xx errors, the output contains the full error message (error.message) and the contents of the details property (error.details) that ValidationError typically uses to provide machine-readable details about validation problems. It also includes error.code to allow a machine-readable error code to be passed through which could be used, for example, for translation.
Am I doing something wrong here, or should this be considered as a bug?
No this is the intended behaviour
Safe error fields
You can set the stack trace as "safe-error-field" so that it will be displayed in production.
For example, the stack field is not displayed by default if you run the loopback in production mode.
If you still want to display the stack field, then change the config json in the server/middleware.json
"final:after": {
"strong-error-handler": {
"params": {
"safeFields": ["stack"]
}
}
}