CODEWITHSUNDEEP
javascriptnode.jsexpress
Dinesh Pandiyan
Dinesh Pandiyan

Reputation: 6299

Express.js response converts snake_case keys to camelCase automatically

I'm working on a small project at work and we have an Express.js based node application running that sends a json response that has keys in snake_case format. We have another node application that consumes this service but the response object keys are accessed in camelCase format here. I'd like to know what happens in the background to make this work.

This is the code in the REST API

app.get('/api/customer/:id', (req, res) => {
    const data = {
        "arr": [{
             "my_key": "609968029"
        }]
    }
    res.send(data);
});

This is how it is consumed in the other node application

getData = (id) => {
  const options = {
    url: `api/customer/${id}`
  };

  return httpClient.get(options)
    .then(data => {
      const arr = data.arr.map(arrEntry => {
        return {
          myKey: arrEntry.myKey
        };
      });

      return {
        arr
      };
    });
};

Here myKey correctly has the data from the REST API but I'm not sure how my_key is converted to myKey for it work.

Upvotes: 3

Views: 3591

Answers (2)

JXLai
JXLai

Reputation: 321

lodash can do this

_.camelCase('Foo Bar');
// => 'fooBar'

Upvotes: 1

Dinesh Pandiyan
Dinesh Pandiyan

Reputation: 6299

Turns out we have used humps library to resolve the response object from keys snake-case to camelCase.

I found this code in the lib call

const humps = require('humps');
...
axios(optionsObj)
  .then(response => {
    resolve(humps.camelizeKeys(response.data));
  })
  .catch(err => {
    reject(err);
  });

Upvotes: 5

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