Playwright is not able to start Microsoft Edge and run tests in it
May 28, 2025Let's say you are using Playwright to execute tests in Microsoft Edge and upon triggering you get "Headless mode is disallowed by the system admin".
Written by Dušan Roštár - the "mr edge case" guy
my twitter : rostacik, my linkedin : rostar, drop me an email : here
Let's say you are using Playwright to execute tests in Microsoft Edge and upon triggering you get "Headless mode is disallowed by the system admin".
In case you need to download separate package you need to install from Windows update you might look at the original Microsoft Update Catalog.
This post documents my fabulous journey through time to uncover the hidden traps of trusting the claim that once you have package.json and package-lock.json and same NodeJS version you are safe.
If you use winget upgrade over your packages, you migt see that some packages fail to update and will stay on the same version. In this article I try to fix this.
In this article I compared isNaN(Date.parse(string)) with isNaN(new Date(string).valueOf()) and isNaN(new Date(string)). There are some funny differences in the results depending on your browser and his JS engine.
Maybe you just use good old http and overlooked it. Try https and things will be fine again :) The hackers will not thank you too.
This small how to is targeted at people who want to run the Bryntum PDF export server with IIS server if they host it's JS part in for example ASP.NET application.
Yes it can, he is quite good at it but you maybe will not get what you want with legacy code. Also you might consider using ChatGPT 4 to generate test, it seems Copilot might generate different results.
Don't ask for ES6, ask for latest EcmaScript version/feature set. Making code use latest ES features will help readability but might hurt performance.
If you try to use nvm under Windows and load default version of node like (expected) : you will see : Reason seems to be that : .nvmrc is…
I was thinking about doing this kind of article for quite some time now, mostly since I discovered Android app named AccuBattery (you can easily download it on play store, no referral links needed here). There are more apps that will tell you the temperature and voltage and current but I will use this one as sample in my article.
I was thinking about doing this kind of article for quite some time now, mostly since I discovered Android app named AccuBattery (you can easily download it on play store, no referral links needed here). There are more apps that will tell you the temperature and voltage and current but I will use this one as sample in my article.
The problem OK so you need to debug remotely again. You have the same os or at least the closest you can get, same .NET version, same tools…
We have all been there. Eval is evil "BUT" here is this HTML element prop and you need to call this like it is. OK, sure, it worked until now. But it was a good old sync JS function. Now there might be an async function and we need to await it. Now what?
This is a small helper I created for myself and colleagues to create names of test for maven from Jenkins list of failed tests.
Getting info about profile visits on Xing.com and eager to know who paid you a visit? Open dev tools and you will know.
PowerShell Invoke-WebRequest has a nice feature, a progress bar which will as you will see turn off immediately. Here is why.
Running karma tests gives me SyntaxError Invalid or unexpected token but the file seems to be OK
This article is for everybody that might run into issue like I did while using latest gulp-sass with NodeJS 12.x LTS.....
At work we use a TS “native” approach with tsconfig.json settings and running tsc compiler approach ....
If you experience similar problems as many other users of Meizu here ....
Yesterday I had the pleasure to install latest update of VS 2017 15.9.0. Unfortunately at the end I was notified about minor problem ...
Chcel by som sa s vami podeliť o jednu drobnosť (iste ide len o glitch) v UX IB mBank ktorá sa zhodou okolností vyskytuje...
Facebook for some time now has the possibility to upload and display your pictures as 360 ones. But ....
I tend to forget some simple things I just don’t use that often. One of these is when working with some ASP.NET....
I am using happily deployments from GitHub to Azure functions, but I wanted to use a repo ....
I just ported my blog to Microsoft Azure and I would like to say I am sorry ....
Find out where to change audio settings in built Skype in Windows 10 is not as easy as it looks like...
We had a small problem I would like to share today. We have Windows 2012 R2 with Jenkis as one of means to build our stuff ...
StyleCop is a tool that runs against C# code (not against IL assemblies – already build code) and based on rules saved either per machine, or per project ...
In this post we will discuss some options you have with calling async functions in constructor of your TypeScript classes.
If you have in your project files you moved to different location or removed but your .csproj still points to lets say - removedFolder/removedSubfolder/removedFile.ts then it might happen VS will recreate folders where you point (in this case removedFolder/removedSubfolder).
maybe @team and @channel is all you need ...
So what would be the common use case , why to bother mask/mute errors on build? Compile is the first test our code need to undergo, like first pass of “unit tests” ...
Na Slovensku niekoľko dní späť potešil operátor 4ka svojich zákazníkov 1GB dátovým balíčkom zdarma. Super, poviete si. Vložíte SIM do telefónu, zapnete dáta a ... nestane sa nič. Hľadáte problém...
Most of developers doesn’t use PowerShell on day to day basis, but Microsoft in Visual Studio 2015 made it 1rst class citizen by making...
podklady ku prednáške ...
If you would install TypeScript nightly as blog says like this (I modified the command, this will install typescript@next package locally and save dependency in devDependencies) ...
If you from time to time would like to send after failed deploy2prod ...
If you are using TypeScript nightly (and only with TypeScript 1.6 up) you can use in your tsconfig.json new property exclude which will mostly be used for node_modules like this ...
If you would like to disable building TypeScript files in your solution for some reason (you want different build workflow, you just work on .cs files and don’t touch .ts files), you had to search for some kind of ifs or comments out to the project file in previous version of Visual Studio...
Type HTMLTableDataCellElement is not defined in Chrome and FireFox, this object is IE only. If you want to test at runtime for TD element in all latest browsers, use HTMLTableCellElement instead. ...
Here is my small take on what is needed in lots of apps that have limited real estate on the screen. To load some (in my case CKEditor) editor with hidden chrome ...
When checking for primitive types in TypeScript , typeof variable === “string” or typeof variable === “number” should do the job. When checking for HTMLElement or HTMLDivElement type of objects, variable instanceof HTMLElement or variable instanceof HTMLDivElement type of check should be the right one.
Just add HintPath node to Microsoft.Web.Infrastructure Reference node that points to where NuGet package is.
Basically you can now limit types that could be used in Array (all only at compile time, same rules apply as for other type checking features of TypeScript)
You can just drag and drop .ts file to .html or .aspx markup and Visual Studio 2013 is intelligent enough to include .js file
I needed simple and short solution for creating custom DTO objects with simple logic for later reuse elsewhere. Function essentialy takes “constructor” argument and returns object with properties that have getters with small piece of logic and are using constructor parameter. No inheritance ...
Since I play these days a lot with PowerShell I need from time to time some simple functionality. Sometimes dead simple.
So you want to search for multiple strings in your files on Windows?
So, you wanted to use momentjs to parse from locale date and time and/or month and day names , or you wanted some locale output from date using .format in your browser, but what you received was a mess?
Dokumenty a github repo
PowerShell installs in one package however there are two versions x86 and x64 (as separate executables that I had to find on my drive) and as you might guessed correctly - they don’t share the same Get-ExecutionPolicy setting!
Funny article name you say and I can only agree, yes 🙂 most of the time you run like hell when you see page with broken certificate. But I will explain why one might need this 🙂
I would like to share one small “feature” I have found on current latest browsers. By “latest browsers” I mean (I tested this behavior on IE 11, FireFox 29 and Chrome 37).
Since I write a lot of JavaScript currently in Visual Studio these days, I lack one of the very common checks in JavaScript and that is testing if object exists.
Filter out only hosts and ports you need. Apply the filter, enjoy.
If you are working on some ASP.NET project and you need to build it even if some files are unbuildable/will not compile...
Nevdojak mi pri hľadaní vhodného internetu do mobilu napadla nasledovná zákerná kombinácia. Možno nieje vhodná pre Vás, je to samozrejme len jedna z možností....
Just wanted to share this small idea/snippet I found on the web (the main reason to write this post was to let you skip my errors so you don’t have to find what to suffix after $(SolutionDir) and let tsc be happy with what VS is calling)...
Since I upgraded my Windows 7 developer box with Internet Explorer 11 I am very satisfied with how Microsoft upgraded developer tools. They have added new stuff and it works (well from time to time IE freezes but that might be also my problem with my JavaScript since other browsers hang/crash from time to time on my code also). But that is another story..
For some reason, account on which you run VS on and on which VS hosts PowerShell has restricted ExecutionPolicy (you can type Get-ExecutionPolicy , select the text and hit CTRL+F8 and should see Restricted as the answer)....
I just wanted to share with you one simple stupid snippet (please note, I am PowerShell newbie so have mercy and if there is any better way, please share in comments, thank you)...
I needed to subscribe from multiple TypeScript files to ready event of document, the usual event where you hook to do some initializations with jQuery, when you need it. There are more ways, to do this....
I needed to subscribe from multiple TypeScript files to ready event of document, the usual event where you hook to do some initializations with jQuery, when you need it. There are more ways, to do this....
At first it seems like development tools freezed. Also IE as such freezed. What I saw was IE with page in the back and tools with note you see above. I clicked on IE icon in taskbar and saw two “windows” like this...
Včera som sa zúčastnil TechDays v Žiline a preto malý krátky článoček o + / – a pár fotos...
Because I had to troubleshoot this weekend in total 2 notebooks (why not booting, unable to install Windows 7, etc.) I came across one useful tool that is able to log what is...
I am happy owner of older Kindle Keyboard (without 3G, it should be 3rd generation of Kindle readers). Since I have version without 3G, I am downloading everything via WiFi at home. I often read articles from our local web magazines or development articles with help of this tool - Kindle It, really good Firefox plugin....
In this article I want to dive a bit into helping you decide (or at least share some thoughts) regarding quite common problem that we had on last Sitecore project and that was there was a need to have some sort of API...
Hi all owners of older Android phones, I belong to you and we all share the same problem, low disk space...
At first, the thing I will write today about in short is not something new that I and only I came up with (since I am not some security research dude, I am just a common .NET dev)...
At first you might ask, why one would like to do this kind of thing and why even write a whole damn article about that. Well the answer is not so common but simple...
This short blog post is about well know fact and all Sitecore veterans will just smile, but for all newbies like me, it will save you some time...
If you pin a program to taskbar in Windows 7 or 8 and want to run it directly without clicking on the icon, you can use Win key + number of the icon from the left. So if would you have icon like this ...
Since I moved to greener pastures from beginning of this month and I work for Danish customer, I am learning Sitecore CMS system (which I see they love in DK) and because I tend to work with latest SW, I installed Windows 8 with built in IIS8...
If you want to access all data in your Grid that you have in DOM in your browser on client, you maybe found this helpful link to Telerik’s help page...
So, you have same problem as me, how to subscribe to clients keyboard events with Telerik’s DropDownList control for ASP.NET MVC? 🙂
Ever encountered this strange popup in VS2010 after several hours of happily working with MVC? And now VS thinks, that something is wrong with your Razor components?
Today very talented colleauge of mine sent out to us very nice catch about requesting resources from .ascx file...
I want to share with you one really nice pitfall I faced at work and that is this nice note once you want to run unit tests inside VS 2010 saying - No tests were run because all loaded or selected tests are disabled once you try to load and run some of them...
Please, disable Save button on whole screen according to role. You as dev will say OK, why not. Then you will come to Lightswitch IDE , right click Save button to create Can Run event handler and you will see (screaming, swearing / insert appropriate) something like this...
We have entity that has reference to another entity. Employee has reference to Status. This second Status table has set for some business requirement that his Summary property must be set to value that can repeat. I know this makes it hard to tell which value from all possible was picked, but say it is so. Another reason is that summary property is displayed as selected value in grid....
I want to share with you one really nice pitfall I faced at work and that is this nice note once you want to run unit tests inside VS 2010 saying - No tests were run because all loaded or selected tests are disabled once you try to load and run some of them...
Today I needed to trace my small ASP.NET application which consists of one .ashx file that will handle requests...
I want to share with you one really nice pitfall I faced at work and that is this nice note once you want to run unit tests inside VS 2010 saying - No tests were run because all loaded or selected tests are disabled once you try to load and run some of them...
Today I learned small thing about deploying LightSwitch apps. Don’t forget to publish for customer with Release set on, because it seems that LighSwitch will publish also code that...
Keďže som potreboval na jednom menšom projekte funkciu ktorá by sa hodila pre vytvorenie peknej URL z bežného názvu článku, rozhodol som sa túto už mnohokrát riešenú funkcionalitu zabaliť do jednej triedy, urobiť pár unit testov a hodiť na GitHub...
Many to Many (or n to m) relationships in real world scenarios are quite common. Unfortunately this cardinality LightSwitch doesn't handle out of box (maybe in next version we will see). But this task can be done. With help of WCF RIA Services. And resources around the internet, like this one...
With smaller screen resolution (or with requirement for bigger grids) comes possibility to create slide-able columns or rows in UI very handy. And in LightSwitch it’s possible with few clicks on checkboxes. 🙂 I will show you how in this small example...
While debugging of LightSwitch apps I get from time to time strange note about failed query that is in the plumbing of every LighSwitch app. App will hang with note in the middle of screen like this ...
Adding custom validation is quite easy task, but currently Microsoft has problem with not updated MSDN article http://msdn.microsoft.com/en-us/library/ff852045.aspx. I just would like to tell you that code snippet on this MSDN page is not working...