middleware-perf.js

import perf    from '../lib/perf.js';
const THRESHOLD = 83; // ~ 5 animation frames

const perfMiddleware = store => next => action => {
    perf.start(action.type);
    let result = next(action);
    perf.end(action.type);
    
    if (perf.duration(action.type) > THRESHOLD) {
        console.warn(`[perf] action ${action.type} took ${perf.duration(action.type).toFixed(2)}ms`, {
            mean:      perf.mean(action.type),
            sdev:      perf.sdev(action.type),
            samples:   perf.getEntriesByName(action.type).length,
        });
    }
    return result;
};

export default perfMiddleware;