Turns non fluent APIs into fluent APIs

npm install taptaptap

Examples

Take Array.prototype.push for example. It returns the new length of the array, making chaining impossible.

const numbers = []
numbers.push(1)
numbers.push(2)

Wrapping the array inside "tap" allows us to chain everything together nicely.

const { tap } = require('taptaptap')

const numbers = tap([])
    .push(1)
    .push(2)

tap uses ES6 proxies to make sure each function gets executed, but returns the initially passed value (in this case, the numbers array).

One more example using classes

class User {
    name = null
    setName(name) {
        this.name = name
    }
    
    getId() {
        return this.id
    }

    save() {
        // persist data

        this.id = this.createUUID() // fill it with new id
        this.createdAt = new Date()

        return true // if everything went well
    }
}

The way the API was built forces us to access it like this.

function createUser(name) {
    const user = new User
    
    user.setName(name)
    user.save()

    return user
}

Using tap we can do

const { tap } = require('taptaptap')

function createUser(name) {
    return tap(new User)
        .setName(name)
        .save()
}

or using an arrow function

const { tap } = require('taptaptap')

const createUser = name => tap(new User).setName(name).save()

Getting values

Since every function just executes the initial value again, you either have to break out of the chain, or tap out of it.

const { tap } = require('taptaptap')

function createUserAndGetId(name) {
    return tap(new User)
        .setName(name)
        .save()
        .tapOut
        .getId()
}

Alternatively, you can also pass a function in the second argument to group common logic.

Turning

const user = User.query().latest().first()

expect(user.name).toBe('test name')
expect(user.bio).toBe('test bio')

to

tap(User.query().latest().first(), user => {
    expect(user.name).toBe('test name')
    expect(user.bio).toBe('test bio')
})