Setup Error Logging in Serverless

Chapter Comments
1

Link to chapter - https://serverless-stack.com/chapters/setup-error-logging-in-serverless.html

2

@jayair Thank you so much for the fantastic tutorials - I have learned so much going through these!

I was wondering about the error handling: it seems to me that errors (except for those from AWS directly re: Auth) are defaulted to 500 errors (via handler-lib.js). Would it not be useful to allow for specifying other response codes (i.e 404) where required?

[Update 15/04/2020]

Would this approach be advisable?

I extended the Error class and created an ApiError class with a statusCode property. In the API endpoint, throw new ApiError("Item not found", 404). In the handlerLib.js I create a statusCode variable defaulted to 500. If the Error has the name ApiError set the statusCode to the statusCode property from the error.

libs/ApiError.js:

export default class ApiError extends Error {
  constructor(message, code) {
    super(message, code);
    this.name = "ApiError";
    this.statusCode = code;
  }
}

libs/handlerLib.js:

...
.catch(e => {
      // Print debug messages
      console.log("Error retrieving note: ", { error: e });
      debug.flush(e);
      let statusCode = 500;
      if (e.name === "ApiError") {
        statusCode = e.statusCode;
      }
      return [statusCode, { error: e.message, errorType: e.name }];
    })
...

For successful Api responses, I return an object with body and statusCode properties which are then used in handlerLib.js too:

...
    // On success
   .then(responseBody => [responseBody.statusCode, responseBody.body])
...

Response object would look like this (get.js):

return {
  body: res.Item,
  statusCode: 201
}
2 Likes
3

Yup we are simply leaving it as 500 errors for now but you can extend it to return the error codes that you want. I would not simply pass the errors from DynamoDB along, it makes more sense to handle any sensitive data before returning it.

1 Like
4

What is the typescript equivalent to this chapter? I am trying to recreate this in typescript but I am hitting a wall with the arguments debug method.

5

I found this “Setup Error Logging in Serverless” page by googling, but it doesn’t seem to be listed in the contents of the tutorial. It starts by saying “Now that we have our React app configured to report errors” but I can’t find the page where that happened. I have no idea which bits of the tutorial should have been punched in for the instructions on this page to work.