exercise.js

////////////////////////////////////////////////////////////////////////////////
// Exercise:
//
// Implement the React bindings for the Redux state manager using context and
// a higher-order component.
//
// 1. Implement <Provider> to make the store accessible on context to the rest
//    of the components rendered below it
// 2. Implement `connect`. It should:
//   a) Return a function that takes a component
//   b) The new function should return a new component that wraps the component
//      passed to it
//   c) The new component, when rendered, will pass state from
//      the store as props to your App component. You'll use the function
//      passed to `connect` to map store state to component props
import React from "react";
import ReactDOM from "react-dom";

import createStore from "./exercise/mini-redux/createStore";
import Provider from "./exercise/mini-redux/Provider";

import App from "./exercise/App";

const store = createStore((state = 0, action) => {
  if (action.type === "INCREMENT") {
    return state + 1;
  } else if (action.type === "DECREMENT") {
    return state - 1;
  } else {
    return state;
  }
});

ReactDOM.render(
  <Provider store={store}>
    <App />
  </Provider>,
  document.getElementById("app")
);