Hyperparams

A strong params inspired library for Express and plain Javascript that's fast and functional.

Quickstart

$ yarn add hyperparams

Observe the following:

const { extract } = require('hyperparams')
const userParams = extract('user', ['email', 'password', { address: ['zip']}])
app.post('/users', (req, res)=>{
  try{
    await User.save(userParams(req.body))
    res.json({all: 'good'})
  } catch(err) {
    res.json({all: 'bad'})
  }
})

We made a userParams a strong-params extractor. This means we didn't do any left-hand-right-hand coding, any brittle deep and-and drilldowns to extract a property.

More importantly, we didn't accept everything that's on body as is, such as an _id property (internal ID on MongoDB, for example), or a malliciously added admin flag, potentially elevating a user's permissions.

Note that when a missing root or property is encountered, we throw an exception and this is by-design. If you'd like an error object, make wrapper and return an {error: ..., value: ...} struct. That's just one suggestion though.

What's next

You can give defaults to hyperparams if you like (these are deep defaults):

// let's say body is: { user: { email: '[email protected]' } }
extract('user', ['email', { foobar: ['foobaz']}], { foobar: { foobaz: 42 } })(body)
// -> { user: { email: '[email protected]', foobar: { foobaz: 42 } } }

And you can couple it with any validation library like ajv or joi.

Strong params vs validation

This is not a validation library. Hence, it will not check types, formats or any of that. If you need to do that, then you can use vanilla object schema validation libraries like ajv or joi; they have features to remove excess properties for varying degrees of support.

More importantly, you can decide that validation as a concerns sits in your model library in any case, and/or even (probably) database constraints.

But note that if you don't need involved type validation at the request layer, and you still a validation library, you'll pay with performance and developer experience.

Here are some numbers to get an idea about speed:

- baseline: joi single prop x 26,949 ops/sec ±1.12% (83 runs sampled)
- baseline: joi flat pick x 13,439 ops/sec ±1.56% (82 runs sampled)
- baseline: ajv single prop x 54,967 ops/sec ±1.98% (78 runs sampled)
- baseline: ajv flat pick x 59,308 ops/sec ±2.08% (84 runs sampled)
- baseline: lodash flat pick x 511,284 ops/sec ±1.43% (83 runs sampled)
- baseline: lodash get x 15,648,434 ops/sec ±1.51% (80 runs sampled)
- hyperparams: nested w/array mapping x 103,790 ops/sec ±1.70% (84 runs sampled)
- hyperparams: single prop x 490,952 ops/sec ±1.61% (83 runs sampled)

Contributing

Fork, implement, add tests, pull request, get my everlasting thanks and a respectable place here :).

Thanks:

To all Contributors - you make this happen, thanks!

Copyright

Copyright (c) 2017 Dotan Nahum @jondot. See LICENSE for further details.