var noop = function(){};

var errorHandler = {
    callback: null,
    init: function (callback) {
        errorHandler.callback = callback || noop;

        window.onerror = errorHandler.script;
        window.addEventListener('error', errorHandler.source, true);
        window.addEventListener('unhandledrejection', errorHandler.promise, true);
    },
    // 记录普通错误
    script: function (message, source, lineno, colno) {
        var stack = source + ':' + lineno + ':' + colno;
        errorHandler.callback('script', message, stack);
    },
    // 记录资源加载错误
    source: function (e) {
        e.preventDefault();
        var target = e.target || e.srcElement;
        var isElementTarget = target instanceof HTMLScriptElement || target instanceof HTMLLinkElement || target instanceof HTMLImageElement;

        // 不是资源加载错误时，直接返回
        if (!isElementTarget) {
            return false;
        }

        var url = target.src || target.href;
        errorHandler.callback('source', 'Unable to load resources', url);
    },
    // 记录promise错误
    promise: function (e) {
        e.preventDefault();
        var error = e.reason || {};
        errorHandler.callback('promise', error.message, error.stack);
    }
};