stacktrace.js

(function(root, factory) {
    'use strict';
    // Universal Module Definition (UMD) to support AMD, CommonJS/Node.js, Rhino, and browsers.

    /* istanbul ignore next */
    if (typeof define === 'function' && define.amd) {
        define('stacktrace', ['error-stack-parser', 'stack-generator', 'stacktrace-gps'], factory);
    } else if (typeof exports === 'object') {
        module.exports = factory(require('error-stack-parser'), require('stack-generator'), require('stacktrace-gps'));
    } else {
        root.StackTrace = factory(root.ErrorStackParser, root.StackGenerator, root.StackTraceGPS);
    }
}(this, function StackTrace(ErrorStackParser, StackGenerator, StackTraceGPS) {
    var _options = {
        filter: function(stackframe) {
            // Filter out stackframes for this library by default
            return (stackframe.functionName || '').indexOf('StackTrace$$') === -1 &&
                (stackframe.functionName || '').indexOf('ErrorStackParser$$') === -1 &&
                (stackframe.functionName || '').indexOf('StackTraceGPS$$') === -1 &&
                (stackframe.functionName || '').indexOf('StackGenerator$$') === -1;
        },
        sourceCache: {}
    };

    var _generateError = function StackTrace$$GenerateError() {
        try {
            // Error must be thrown to get stack in IE
            throw new Error();
        } catch (err) {
            return err;
        }
    };

    /**
     * Merge 2 given Objects. If a conflict occurs the second object wins.
     * Does not do deep merges.
     *
     * @param {Object} first base object
     * @param {Object} second overrides
     * @returns {Object} merged first and second
     * @private
     */
    function _merge(first, second) {
        var target = {};

        [first, second].forEach(function(obj) {
            for (var prop in obj) {
                if (obj.hasOwnProperty(prop)) {
                    target[prop] = obj[prop];
                }
            }
            return target;
        });

        return target;
    }

    function _isShapedLikeParsableError(err) {
        return err.stack || err['opera#sourceloc'];
    }

    function _filtered(stackframes, filter) {
        if (typeof filter === 'function') {
            return stackframes.filter(filter);
        }
        return stackframes;
    }

    return {
        /**
         * Get a backtrace from invocation point.
         *
         * @param {Object} opts
         * @returns {Array} of StackFrame
         */
        get: function StackTrace$$get(opts) {
            var err = _generateError();
            return _isShapedLikeParsableError(err) ? this.fromError(err, opts) : this.generateArtificially(opts);
        },

        /**
         * Get a backtrace from invocation point.
         * IMPORTANT: Does not handle source maps or guess function names!
         *
         * @param {Object} opts
         * @returns {Array} of StackFrame
         */
        getSync: function StackTrace$$getSync(opts) {
            opts = _merge(_options, opts);
            var err = _generateError();
            var stack = _isShapedLikeParsableError(err) ? ErrorStackParser.parse(err) : StackGenerator.backtrace(opts);
            return _filtered(stack, opts.filter);
        },

        /**
         * Given an error object, parse it.
         *
         * @param {Error} error object
         * @param {Object} opts
         * @returns {Promise} for Array[StackFrame}
         */
        fromError: function StackTrace$$fromError(error, opts) {
            opts = _merge(_options, opts);
            var gps = new StackTraceGPS(opts);
            return new Promise(function(resolve) {
                var stackframes = _filtered(ErrorStackParser.parse(error), opts.filter);
                resolve(Promise.all(stackframes.map(function(sf) {
                    return new Promise(function(resolve) {
                        function resolveOriginal() {
                            resolve(sf);
                        }

                        gps.pinpoint(sf).then(resolve, resolveOriginal)['catch'](resolveOriginal);
                    });
                })));
            }.bind(this));
        },

        /**
         * Use StackGenerator to generate a backtrace.
         *
         * @param {Object} opts
         * @returns {Promise} of Array[StackFrame]
         */
        generateArtificially: function StackTrace$$generateArtificially(opts) {
            opts = _merge(_options, opts);
            var stackFrames = StackGenerator.backtrace(opts);
            if (typeof opts.filter === 'function') {
                stackFrames = stackFrames.filter(opts.filter);
            }
            return Promise.resolve(stackFrames);
        },

        /**
         * Given a function, wrap it such that invocations trigger a callback that
         * is called with a stack trace.
         *
         * @param {Function} fn to be instrumented
         * @param {Function} callback function to call with a stack trace on invocation
         * @param {Function} errback optional function to call with error if unable to get stack trace.
         * @param {Object} thisArg optional context object (e.g. window)
         */
        instrument: function StackTrace$$instrument(fn, callback, errback, thisArg) {
            if (typeof fn !== 'function') {
                throw new Error('Cannot instrument non-function object');
            } else if (typeof fn.__stacktraceOriginalFn === 'function') {
                // Already instrumented, return given Function
                return fn;
            }

            var instrumented = function StackTrace$$instrumented() {
                try {
                    this.get().then(callback, errback)['catch'](errback);
                    return fn.apply(thisArg || this, arguments);
                } catch (e) {
                    if (_isShapedLikeParsableError(e)) {
                        this.fromError(e).then(callback, errback)['catch'](errback);
                    }
                    throw e;
                }
            }.bind(this);
            instrumented.__stacktraceOriginalFn = fn;

            return instrumented;
        },

        /**
         * Given a function that has been instrumented,
         * revert the function to it's original (non-instrumented) state.
         *
         * @param {Function} fn to de-instrument
         */
        deinstrument: function StackTrace$$deinstrument(fn) {
            if (typeof fn !== 'function') {
                throw new Error('Cannot de-instrument non-function object');
            } else if (typeof fn.__stacktraceOriginalFn === 'function') {
                return fn.__stacktraceOriginalFn;
            } else {
                // Function not instrumented, return original
                return fn;
            }
        },

        /**
         * Given an error message and Array of StackFrames, serialize and POST to given URL.
         *
         * @param {Array} stackframes
         * @param {String} url
         * @param {String} errorMsg
         */
        report: function StackTrace$$report(stackframes, url, errorMsg) {
            return new Promise(function(resolve, reject) {
                var req = new XMLHttpRequest();
                req.onerror = reject;
                req.onreadystatechange = function onreadystatechange() {
                    if (req.readyState === 4) {
                        if (req.status >= 200 && req.status < 400) {
                            resolve(req.responseText);
                        } else {
                            reject(new Error('POST to ' + url + ' failed with status: ' + req.status));
                        }
                    }
                };
                req.open('post', url);
                req.setRequestHeader('Content-Type', 'application/json');

                var reportPayload = {stack: stackframes};
                if (errorMsg !== undefined) {
                    reportPayload.message = errorMsg;
                }

                req.send(JSON.stringify(reportPayload));
            });
        }
    };
}));