This is all the information I could capture about a recent user crash: "Window.OnError - Base.js - Line 1775 [object XMLHttpRequest]"
var ErrorPromise = WinJS.Class.define(
function ErrorPromise_ctor(value) {
if (tagWithStack && (tagWithStack === true || (tagWithStack & tag.errorPromise))) {
this._stack = WinJS.Promise._getStack();
}
this._value = value;
callonerror(this, value, detailsForError);
}, {
cancel: function () {
/// <signature helpKeyword="WinJS.PromiseStateMachine.cancel">
/// <summary locid="WinJS.PromiseStateMachine.cancel">
/// Attempts to cancel the fulfillment of a promised value. If the promise hasn't
/// already been fulfilled and cancellation is supported, the promise enters
/// the error state with a value of Error("Canceled").
/// </summary>
/// </signature>
},
done: function ErrorPromise_done(unused, onError) {
/// <signature helpKeyword="WinJS.PromiseStateMachine.done">
/// <summary locid="WinJS.PromiseStateMachine.done">
/// Allows you to specify the work to be done on the fulfillment of the promised value,
/// the error handling to be performed if the promise fails to fulfill
/// a value, and the handling of progress notifications along the way.
///
/// After the handlers have finished executing, this function throws any error that would have been returned
/// from then() as a promise in the error state.
/// </summary>
/// <param name="onComplete" type="Function" locid="WinJS.PromiseStateMachine.done_p:onComplete">
/// The function to be called if the promise is fulfilled successfully with a value.
/// The fulfilled value is passed as the single argument. If the value is null,
/// the fulfilled value is returned. The value returned
/// from the function becomes the fulfilled value of the promise returned by
/// then(). If an exception is thrown while executing the function, the promise returned
/// by then() moves into the error state.
/// </param>
/// <param name="onError" type="Function" optional="true" locid="WinJS.PromiseStateMachine.done_p:onError">
/// The function to be called if the promise is fulfilled with an error. The error
/// is passed as the single argument. If it is null, the error is forwarded.
/// The value returned from the function is the fulfilled value of the promise returned by then().
/// </param>
/// <param name="onProgress" type="Function" optional="true" locid="WinJS.PromiseStateMachine.done_p:onProgress">
/// the function to be called if the promise reports progress. Data about the progress
/// is passed as the single argument. Promises are not required to support
/// progress.
/// </param>
/// </signature>
var value = this._value;
if (onError) {
try {
if (!onError.handlesOnError) {
callonerror(null, value, detailsForHandledError, this, onError);
}
var result = onError(value);
if (result && typeof result === "object" && typeof result.done === "function") {
// If a promise is returned we need to wait on it.
result.done();
}
return;
} catch (ex) {
value = ex;
}
}
if (value instanceof Error && value.message === canceledName) {
// suppress cancel
return;
}
// force the exception to be thrown asyncronously to avoid any try/catch blocks
//
WinJS.Utilities.Scheduler.schedule(function () {
throw value;
}, WinJS.Utilities.Scheduler.Priority.normal, null, "WinJS.Promise._throwException");
},
It is pointing me to the lines after: "// force the exception to be thrown asyncronously to avoid any try/catch blocks" (including the spelling mistake)
All of my WinJS.Promises have error handling (at the bottom of the promise), but this is breaking out of that chain?
I am not sure how to proceed here or where I should be looking for the bug that caused this. Would this be caused by a bug within a promises error handling, or is it likely within the promise itself?
Is there any way I can log more information about this crash, something I can add to my promise chain? Any way I can break out the data from the [object XMLHttpRequest]?
The code that captured the error is simply:
window.onerror = function (msg, url, linenumber) {}
Can I check for "XMLHttpRequest" in 'msg' and then somehow breakout that object to information that is more helpful? Would converting it from an object to a string work, or is there a better way to do this?
Thanks for reading my question.
