zanpakuto

$ yarn add zanpakuto

compose

It's like Object.assign(), but even more.

import { compose } from 'zanpakuto';
...
compose({})
    .if(hasFoo && hasBar, {
        foo: 'Foo',
        bar: 'Bar'
    }).elseif(hasFoo, {
        foo: 'Foo'
    }).elseif(hasBar, {
        bar: 'Bar'
    }).else({
        noFooNoBar: 'NoFooNoBar'
    }).val();

| hasFoo \ hasBar | true | false | | --------------- | --------------------------- | ------------------------------ | | true | { foo: 'Foo', bar: 'Bar' }| { foo: 'Foo' } | | false | { bar: 'Bar' } | { noFooNoBar: 'NoFooNoBar' } |

Example

Suppose you compose an HTTP request to upload a file. You decide to set content type based on a file extension and apply gzip for javascript and css files.

import { compose } from 'zanpakuto';
...
const createRequest = (payload: any, fileExt: string) => 
    compose({
        body: { ...payload }
    }).if(fileExt === '.js', {
        contentType: 'text/javascript'
    }).elseif(fileExt === '.css', {
        contentType: 'text/css'
    }).else({
        contentType: 'application/octet-stream'
    }).if(fileExt === '.js' || fileExt === '.css', {
        encoding: 'gzip'
    }).val();

API

| method | description | | ------ | ------------- | | compose<A extends {}>(a: A = {} as any): IComposer<A> | Creates a wrapper around a given object a: A that is a context object. | | append<B>(b: B): IComposer<A | B> | Appends a given object b to the context A | | if<B>(condition: boolean, b: B): IComposer<A | B> | Appends a given object b to the context A if and only if the condition is satisfied. | | elseif<C>(condition: boolean, c: C): IComposer<A | C> | Appends a given object c to the context A if and only if the condition is satisfied and a previous conditions were falsy. | | else<D>(d: D): IComposer<A | D> | Appends a given object d to the context A if all previous conditions were falsy. | | val(): A | Simply returns the context object A. |

export interface IComposer<A> {

    append<B>(b: B): IComposer<A | B>;

    if<B>(condition: boolean, b: B): IComposer<A | B>;

    elseif<C>(condition: boolean, c: C): IComposer<A | C>

    else<D>(d: D): IComposer<A | D>;

    val(): A;
}

License

MIT