I've recently switched from chrome to firefox for greasemonkey development. I have some problems with debugging.
The following func
I meant to write:
self = this;
but instead I wrote
this=self;
Self wasn't defined, so the script didn't run, however, nor did I get any javascript error. Why and can I get them somehow? I get some errors.
Unfortunately, Greasemonkey - and javascript in general, along with at least a few other non-compiled languages - do not give very good debugging errors... I can't count the number of times it tells me there is a missing ) at the end of an argument list that doesn't exist, and it turns out my error is elsewhere...
When a script of mine won't run I add an alert after any value assignments and if they don't alert or alert the wrong data I have found the problem... for your example above I would debug by:
this=self;
alert(self);
Although I would probably see the problem when I went to add the alert, but if I didn't notice - the alert either wouldn't pop up or it would have the wrong value... and if it didn't pop up, the error console would likely say self not defined.
Related
I released a Chrome DevTools extension a couple years ago that uses
chrome.devtools.panels.elements.createSidebarPane(title, callback)
to add an ExtensionSidebarPane. This worked fine until Chrome 92. Now the Pane is created with the title, but it is blank.
The calls I am using are still documented: https://developer.chrome.com/docs/extensions/reference/devtools_panels/, but the example code that I used has been moved to into the mv2-archive section of the google-extension-samples repo. And the chrome-query example code no longer works either. So maybe that means it is unsupported now. On the other hand, everything I have found so far seems to say v2 should be supported to the end of 2021. And I haven't found any alternative v3 examples of adding info to the devtools UI.
Obviously createSidebarPane is getting called, because the blank pane is created with the expected title. And intentionally throwing an error in the callback shows that it is getting called with the expected ExtensionSidebarPane object as a parameter, it's just that calling setExpression or setObject on it doesn't do anything. I am not seeing any other errors or warnings.
I would hate to retire my extension, since I know people use it, but I am not sure what else to try.
So Flow only works correctly the first time I run it, and then I have to restart my computer before it'll work correctly again.
Specifically, the problem I'm seeing is that we are using the Flow language to add type annotations to our JS code. Our linter script is setup to run flow type checking among other things. However, when I fix an issue in my code and then rerun the linter script, it still comes back with the exact same errors... BUT when it shows the piece of code where the error is supposed to be, it actually shows my updated code that's fixed.
So as an example, I had a file I copied into the project, that I didn't think I really needed, but maybe I would. So I copied it in just in case. Well then it came up with a bunch of linter errors, so I decided to just delete the file since I didn't really need it. So then I run "yarn lint --fix" again, but it's still complaining about that file, EVEN THOUGH THE FILE DOESN"T EXIST! Now interestingly, where the linter output is supposed to show the code for those errors it's just blank.
Or another example, let's say I had a couple of functions in my code:
100: function foo() {}
...
150: function bar() {}
And foo has a lot of errors because it was some throw away code I don't need anymore and so I just delete it. So the new code looks like:
100: function bar() {}
Well I rerun the linter and get an error like:
Error ------------------------ function foo has incorrect
something...blah blah
src/.../file.js
100| function bar() {}
I also tested this out on a coworker's machine and they got the same behavior that I did. So it's not something specific to my machine, although it could be specific to our project?
Note: There doesn't appear to be a tag for Flow, but I couldn't post without including at least one tag, so I used flowlang even though that's actually a different language :-( I'm assuming that anyone looking for flow would also use that tag since it's the closest.
The first time you launch Flow it starts up a background process that is then used for subsequent type checking. Unfortunately this background process is extremely slow, and buggy to boot. In linux you can run:
killall flow
To stop the background process. Then if you rerun the flow type checker, it will actually see all your latest changes.
I'm working on a Windows Store app and I'm getting a WinRT error that doesn't really give me any information so I would like to know how to understand these sorts of errors.
Basically I get the error on the following line which is called inside OnPointerPressed:
m_gestureRecognizer->ProcessDownEvent(args->GetCurrentPoint(nullptr));
The error is:
First-chance exception at 0x76F54B32 (KernelBase.dll) in DXAML2.exe: 0x40080201: WinRT originate error (parameters: 0x80070057, 0x00000044, 0x03CEE72C).
This error didn't used to appear, the only thing I've changed is that this line is now wrapped in an if clause which tests if the current pointer's PointerId is the same as one I've stored just using == such as:
if(args->GetCurrentPoint(nullptr)->PointerId == m_UIPointerID)
I have no idea why this has started happening.
So my question is in two parts:
More generally, how do I understand what an error such as the above means?
And does anyone know this error has suddenly started happening now that I check the pointerId?
Thanks for your time.
P.S. I guess another thing that has changed is that there will already be 2 pointers on the screen (the one that gets pushed into this GestureRecognizer) as well as another one, hence the PointerId check.
"How to Decipher such an error"...
For any WinRT originate error, you can take the third address in the parameters list (in your example, 0x03CEE72C), and find a description of your error in the memory window.
While debugging, break when your error is thrown and open the memory window via Debug -> Windows -> Memory -> Memory 1
Copy and paste the address to get your "easy-to-find" error message.
As Raman said - it's good to look up the hex values shown. The first one is the memory location which won't tell you much without the symbols/source, which in this case is reported directly by Windows. Perhaps the public symbols can shed some more light on where the error came from, but the error code lookups are more helpful.
If you Bing for 0x80070057 you will find an MSDN article on Common HRESULT Values which lists
E_INVALIDARG : One or more arguments are not valid : 0x80070057
It doesn't give you all the details of course, so you're off to theorize. Perhaps you can only call args->GetCurrentPoint(nullptr) once and you should store/reuse the value? Maybe gesture recognizer is not configured correctly? Maybe the app window is not visible at the time the exception is thrown or the thread is wrong. Maybe some expected calls to gesture recognizer were missed due to filtering those out with these "if" statements.
I have followed Lee Brimelow's tutorials (part 1, part 2), but somehow my project doesn't work as expected.
Currently, publishing "src/Secondary.as" to "www/assets/swf/secondary.swf" works properly, however when trying to run "src/Main.as", an error shows up:
Exception fault: TypeError: Error #1007: Instantiation attempted on a non-constructor.
at Main/init()[/Volumes/DOCUMENTS/Tests/AS3/test-workers/src/Main.as:52]
at Main()[/Volumes/DOCUMENTS/Tests/AS3/test-workers/src/Main.as:32]
If anybody has time, you can look at my code on Github and maybe see where I screwed up? Thanks a bunch!
As your error message says: the problem raised in Line 52 in your Main.init()method. What you try to do there is to create a new instance of SecondarySWF. I would say that your embedment of Secondary class into SecondarySWF doesn't work properly, so it is not available in your init-method. You should set a breakpoint at the first line of your init-method and when the debugger reaches this point check what's in SecondarySWF. I expect that there's nothing in that variable, so what your new SecondarySWF() then means actually is new null().
Because you embed your secondary.swf with a MIME-type specified the Flex compiler ignores it because it is unable to detect the actual type of data in the loaded file. I found this post on Adobe's cookbook page that explains what you have to do in addition to adding the file using [Embed]. Hope this will fit your needs.
I've attempted to make some modifications to a userscript to enable it to work under Chrome, but when I drag it into Chrome's window in order to install it, a dialog pops up and says 'Invalid Script Header'.
I've tried to use the Developer Tools, and built-in Javascript Console, to debug any errors occurring, but nothing appears to list any information.
Console.app does not list anything meaningful, except for the same error message I already know.
[0x0-0x2d02d].com.google.Chrome: [346:1547:16686819618022:ERROR:extension_error_reporter.cc(55)] Extension error: Invalid script header.
How can I reasonably debug this error message and figure out what about the header is incorrect?
I'm using Chrome 15.0.861.0 on the dev channel, under OS 10.7 Lion.
I finally stumbled across the answer to this question, amusingly via a Chromium Bug Report.
As it turns out, the answer to my question was in the (significantly brief) Userscript Documentation for Chrome page.
With Greasemonkey-style #include rules, it is not possible for Chrome to know for certain the domains a script will run on (because google.* can also run on google.evil.com). Because of this, Chrome just tells users that these scripts will run on all domains, which is sometimes scarier than necessary. With #match, Chrome will tell users the correct set of domains a user script will run on.
As it turns out, I had been using #match http://*musicbrainz.org in an attempt to match www.musicbrainz.org as well as musicbrainz.org, but per the quoted text, that doesn't save you from accidentally matching evilmusicbrainz.org. So, my solution was to use two lines:
#match http://*.musicbrainz.org
#match http://musicbrainz.org
Type:
debugger;
Somewhere in the code, and the Web Inspector will pop up in that location. I have answered similar question here Chrome debugger inject javascript
I figured out while I got the same error message ( INVALID SCRIPT HEADER ) that it accoured cause of a typo between the // ==UserScript== Header info.
wronge line
// #run-at document.end
corrected line
// #run-at document-end