js-pattern-matching
In waiting Pattern Matching proposal adoption
https://github.com/tc39/proposal-pattern-matching#motivating-examples
Install
npm install @tpoisseau/pattern-matching
npm install 'https://github.com/tpoisseau/js-pattern-matching#1.0.5'
Getting Starting
import pattern from '@tpoisseau/pattern-matching'
import {objectStrictLike} from '@tpoisseau/pattern-matching/comparators'
function todoApp(state=initialState, action) {
return pattern(action)
.match({type: 'set-visibility-filter'}, ({filter: visFilter}) => ({...state, visFilter}))
.match(objectStrictLike({type: 'add-todo'}), ({text}) => ({...state, todos: [...state.todos, {text}]})
.match({type: 'toggle-todo'}, ({index}) => ({
...state,
todos: state.todos.map(({...item, done}, idx) => ({...item, done: idx === index ? !done : done}),
})
.default(state)();
}