https://www.npmjs.com/package/infer-values

README.md

Beware, It is really trivial and slow

JSON.parse(JSON.stringify()) is not really fast or efficient, but stringify has convenient replacer parameter

Useful for converting request query values to integers and booleans

Lets say you have lots of stuff in query

app.get('/query', (req, res) => res.send(req.query))
app.get('/infer', (req, res) => res.send(inferValues(req.query)))

GET /sign?url=https%3A%2F%2Fsource.unsplash.com%2Ffeatured%2F500x500&resize%5Bwidth%5D=200&resize%5Bheight%5D=150&resize%5BwithoutEnlargement%5D=true&output%5Bquality%5D=6&output%5Bformat%5D=jpeg

will output

{
  "url": "https://source.unsplash.com/featured/500x500",
  "resize": {
    "width": "200",
    "height": "150",
    "withoutEnlargement": "true"
  },
  "output": {
    "quality": "6",
    "format": "jpeg"
  }
}

GET /infer?...

{
  "url": "https://source.unsplash.com/featured/500x500",
  "resize": {
    "width": 200,
    "height": 150,
    "withoutEnlargement": true
  },
  "output": {
    "quality": 6,
    "format": "jpeg"
  }
}

index.js

const bool = { true: true, false: false, null: null }

const inferValue = (key, value) =>
  bool.hasOwnProperty(value) //
    ? bool[value]
    : parseFloat(value) || value

const inferValues = object => JSON.parse(JSON.stringify(object, inferValue))

module.exports = inferValues

package.json

{
  "name": "infer-values",
  "version": "1.0.2",
  "repository": {
    "type": "git",
    "url": "git@gist.github.com:d5ad2cae104a644536cbd60dbe4af619.git"
  },
  "description": "Leveraging `replacer` parameter of `JSON.stringify`.",
  "main": "index.js",
  "scripts": {
    "test": "node test.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC"
}

test.js

const assert = require('assert')
const inferValues = require('.')

assert.deepStrictEqual(
  inferValues({
    rotate: {
      angle: 'null'
    },
    bool: 'false',
    int: '555',
    float: '56.33',
    fancy: '4e3',
    string: 'as is',
    beware: '567e-2',
  }),
  {rotate: { angle: null },
    bool: false,
    int: 555,
    float: 56.33,
    fancy: 4000,
    string: 'as is',
    beware: 5.67,
  }
)