express create standard JSON return format

Question

I'm new to express, currently if I want to send a response I would do the following

//...
res.json({
  status: 200,
  message: "success",
  data: "something"
})
//...

for all my controllers functions I would do it this way. I guess this is kind of overwhelming so I was thinking if it's possible to make a generalized version of response.

so after some search I found there is 2 ways of achieving this:

1. use a middleware that runs at the end of each route

I found this answer. which made it clear but I think it's a waste of time and my controller then won't be readable enough and I must do the following in every controller function

req.responseObject = response;
return next()

2. override response class of the express itself

this is much promising, but unfortunately after so many tries and following express docs I couldn't get it to work here is what I've tried so far

I've created this util function here:

//myRes.js
module.exports = function (code, message, payload) {
  return this.status(code).json({
    status: 'success',  // this will be variable according to whatever code I get
    code: code,
    message: message || '',
    payload: payload || '',
  });
};

then I've added this line to app.js

// app.js
const express = require('express');
const app = express();
const myRes= require('./utils/myRes');
app.response.send = myRes;
//...

and this is how I use it on my controller

res.send(200, "hello world", [{"key": "value"}])

when I try to run this I got this Error stack

RangeError: Maximum call stack size exceeded
    at JSON.stringify (<anonymous>)
    at stringify ([project_dir]\node_modules\express\lib\response.js:1123:12)
    at ServerResponse.json ([project_dir]\node_modules\express\lib\response.js:260:14)
    at ServerResponse.module.exports [as send] ([project_dir]\src\utils\response.js:2:28)
    at ServerResponse.json ([project_dir]\node_modules\express\lib\response.js:267:15)
    at ServerResponse.module.exports [as send] ([project_dir]\src\utils\response.js:2:28)
    at ServerResponse.json ([project_dir]\node_modules\express\lib\response.js:267:15)
    at ServerResponse.module.exports [as send] ([project_dir]\src\utils\response.js:2:28)
    at ServerResponse.json ([project_dir]\node_modules\express\lib\response.js:267:15)
    at ServerResponse.module.exports [as send] ([project_dir]\src\utils\response.js:2:28)
    at ServerResponse.json ([project_dir]\node_modules\express\lib\response.js:267:15)
    at ServerResponse.module.exports [as send] ([project_dir]\src\utils\response.js:2:28)
    at ServerResponse.json ([project_dir]\node_modules\express\lib\response.js:267:15)
    at ServerResponse.module.exports [as send] ([project_dir]\src\utils\response.js:2:28)
    at ServerResponse.json ([project_dir]\node_modules\express\lib\response.js:267:15)
    at ServerResponse.module.exports [as send] ([project_dir]\src\utils\response.js:2:28)

why JSON.stringify is complaining I haven't used this function on my entire application

also I am not just capped to these 2 solutions you can suggest other ways if you think it's better

This is not an answer to your question per se but you don't need "status" and "code" in your response, that should be handled by the protocol. Read https://www.codecademy.com/articles/what-is-rest. Usually a success is returned with status code 200 and that should be enough. — Ariel, Aug 06 '21 at 14:48
Ok, the problem might be that ".json" actually calls ".send" making it a recursive call. https://github.com/expressjs/express/blob/884e080a19015a81a46aef73792be12ad3220715/lib/response.js#L239-L267 — Ariel, Aug 06 '21 at 14:52
Try modifyng "app.response.send = myRes;" to "app.response.customSend = myRes;" and calling that function instead — Ariel, Aug 06 '21 at 15:01
Don't forget to read the link I've pasted before. Good luck. — Ariel, Aug 06 '21 at 15:03

score 0 · Answer 1 · answered Aug 06 '21 at 17:40

clarifying what @Ariel said in the comments

Express response calls send internally refer to this function from express at lines [120, 123, 136] and that was causing a infinite loop that's why it was saying

Maximum call stack size exceeded

so all I needed to do is to change my function name from send to maybe "sends" and that just worked

it was a bad idea trying to overwrite the built in send function

express create standard JSON return format

1. use a middleware that runs at the end of each route

2. override response class of the express itself

1 Answers1