Put something in, reduce it down, and use the output
$ npm install --save simmer
const simmer = require('simmer')
const addExclamation = i => i + '!'
simmer([i => `Hello ${i}`, addExclamation], 'World') // 'Hello World!'simmer provides a single utility function that accepts a function or array of functions and an input to pass to the function or first function in the array.
If a single function is provided, simmer returns a Promise of the function with the input as the argument.
If an array of functions is provided then simmer recursively executes each function in the array, passing the initial input or the result of the preceeding function as the argument.
simmmer is just a utility, but it provides opportunity to write interesting code with small building blocks.
Want to accept some data, mutate that data, then validate that it fits a shape/schema? simmer makes it easy to create a list of functions and pass in data that will pass through the functions in order.
const input = {
firstName: 'Paul',
lastName: 'Molluzzo',
title: 'JavaScript Developer',
twitter: 'paulmolluzzo'
}
const validateInput = input => {
if (!input.firstName || !input.lastName) {
throw new Error('Expected an object with a first and last name')
}
return input
}
const createName = input => {
input.fullName = [input.firstName, input.lastName].join(' ')
return input
}
const linkifyTwitter = input => {
input.twitter = `https://twitter.com/${input.twitter}`
return input
}
const removeTitle = input => {
delete input.title
return input
}
const validateOutput = input => {
if (input.title) {
throw new Error('Titles should be removed!')
}
return input
}
simmer([validateInput, createName, linkifyTwitter, removeTitle, validateOutput], input)
.then(r => {
console.log(r) // {"fullName": "Paul Molluzzo", firstName: "Paul", lastName: "Molluzzo", "twitter": "https://twitter.com/paulmolluzzo"}
})Using the same example above, it's possible to create a curried version of the same functionality by calling simmer with no input.
const curriedExample = simmer([validateInput, createName, linkifyTwitter, removeTitle, validateOutput])
// delicious!
curriedExample({
firstName: 'Paul',
lastName: 'Molluzzo',
title: 'JavaScript Developer',
twitter: 'paulmolluzzo'
})This work is heavily inspired by DataPoint, in particular the ListReducer, FunctionReducer, and enlightening discussions with Acatl Pacheco and Matthew Armstrong. 🙌🙌🙌
MIT © Paul Molluzzo