personalNotes.md

This file has very little to nothing actual with code but my personal experience of coming to the solutions after hours of research & testing.

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02:35PM GMT+5 august-11-2020.

So during my manual testing I saw keyboard commands (navigate back & left,right) stopped working. This one was something new because Keyboard commands were working fine on debug mode.

• Main reason to implement keyboard commands were to make navigation easy in desktop apps.
• So it tested debug & release on Windows, Linux & Android (emulator & real device) behavior was same.
• In logs I found out that in RawKeyboardListener.onKey(event) method I was using event.logicalKey.debugName to recognize key.
• And event.logicalKey.debugName was null in release mode.
• I thought may be master channel had something internal broken.
• So I followed the the standard brute force debugging like changed channels (master, dev & stable).
• As expected that didn't worked out.
• When I downloaded the old build release from my github I was working fine.
• Then I scrolled through Flutter github issue & stack overflow but couldn't find anything similar to my problem.
• I post my problem on Flutter Discord with a sample project integrated with RawKeyboardListener.
• Few minutes later a gentleman told me debugName property is for debugging only & is null on release. So I've to use static LogicalKeyboardKey class to recognize keys.
• And that's how I solved my problem but this time it only took few hours.

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09:08AM GMT+5 august-09-2020.

So I've been trying to run test driver on android devices for almost 3 days & was just able to solve it a few minutes ago. I was about to implement a very horrible solution which could've made my life a living hell.

Some technical reasons:

• My main reason to implement test driver was to take screenshots of every supported platform via github actions.
• That would help me see state of every integrated screen.
• I can showcase key screens on github readme which I don't have update by myself every time.
• Now I successfully integrated the complete test driver with screenshot flow for windows app.
• But when I get started on android it didn't worked & got the taking too much time on load error.
• I got the idea that something is blocking the rendering that's why driver wasn't able to find widgets by keys.
• So I started stripping the app_test.dart to only bare chunk testing.
• But only if development was that easy.
• Then I started stripping app.dart to basic boilerplate which we mostly see in examples.
• Again only if development was that easy.
• Then I thought it may have something to do with flutter sdk version.
• But that didn't worked either.
• Then I thought some thing in the realm of native android is causing that.
• I upgraded gradle, buildSdkVersion & native libraries. But still no success.
• It came to my mind that may be native firebase or crashlytics could be the hidden cause of conflict.
• So I built a new basic project & added test deriver & added so basic taps & it worked.
• Now I my doubt was strong but not that much confirmed.
• I added the basic app & test to my app which was bundled with firebase or crashlytics. It worked.
• My doubt was clear that those libraries aren't the cause of error. Theres something in my dart which is working weird in android.
• So I started stripping down my Navigator.dart to just Material(home: HomeScreen()) & boom it worked.
• Now it's confirmed that Navigator.dart is the home of hidden error.
• I started adding code back chunk by chunk in Navigator.dart & found out the cause.
• Error was produced when I attached my AppLocalizations.delegate.
• I started adding logs & stripping code in AppLocalizations.dart. Found AppLocalizations.load() was the issue.
• In android app couldn't get past rootBundle.loadString().
• In this github issue it mentions that loadString() use compute() method. Which basically spawns a new isolate(sort of new thread in dart).
• According to the theory which I came up in this journey is App basically runs as isolate & when the app spawns a new isolate it cause some sync conflict with driver as driver is connected to main isolate (the App) & isn't aware of the existence or depends on any other isolates spawn by app.
• Now changing rootBundle.loadString() to rootBundle.load() & doing my custom parsing did solve the issue.
• It all could've been avoided if documentation had notes about it.
• If you're wondering why It worked on windows & linux not on android my theory is in desktop environment compute() must've done operation so fast that It didn't left the main isolate hanging because native desktop apps running on OS are way faster than android app running on device or emulator.
• Or another theory is that's how code behave differently on x86/x64 & arm32/arm64.

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10:49AM GMT+5 july-31-2020.

So I was about to giving up the whole automate testing with full window screenshots idea for desktop apps. Because I wasn't getting anywhere with it & results for problems were very bad or not very clear.

Some technical reasons:

• Couldn't find any native cli command for windows to capture screenshot.
• Then decided to compile my own small cross platform go-lang library so i don't have to waste my time again for mac & linux. Github actions is integrated so I don't have to compile for all OS by my self & can run binary without go lang dependency.
• Now it was time to fight the real monster maximize windows frame via cli.
• Again Couldn't find any native cli command for windows to maximize running app. There were native solutions to maximize.
• After searching I found 2 solutions windowMode.bat & CMDOW.
• Few hours before success I was looking to attach test driver to an up & running app instance.
• I was able to found two outdated articles on medium Blazingly Fast Flutter Driver Tests & Hot Reload For Flutter Integration Tests.
• NGL before these articles I totally lost the hope of integrating my idea of maximize app with full screenshot.
• But in Hot Reload For Flutter Integration Tests article author use ENV variable to save the connection port so later it can be passed to test driver.
  • Now I had a crazy idea in my mind.
  • How about I make a dart wrapper script.
  • Which will run an debuggable app instance.
  • When app is up and running I could maximize the window fram then attach the test driver.
  • But BS between powershell & cmd I had very hard time testing SHARED variable thing.
  • I tried loads of methods like [PS] $env:KEY=VALUE, [PS] SET KEY VALUE, [CMD] SET KEY=VALUE & SETX \M KEY VALUE in dart script, powershell & cmd.
  • But after hours of testing & not getting a good result I throw the variable sharing idea.
• Now I started tweaking test_driver/app_test.dart file again if I could some how make it run by adding delays in between or before execution.
• Then next day in the morning I started testing a mix of solutions form both articles with updated arguments & stuff.
• In between my testing I get this error Error: Not found: 'dart:ui' & some thing not-nullable & int? (I can't remember exact stack trace can't find the old one) like this error.
• Now this int? keyword hits me because I was using latest dart sdk 2.8.4 & this version supported ? nullable safety.
• Now I had doubts of having 2 dart instances on my machine.
• After checking the dart which was bundled with flutter SDK was using dart 2.9.0-21.0.dev.flutter-9dca49e71e.
• Version so after removing my system installed dart 2.8.4 I was able to run my code.
• But still my tweaks didn't work.
• Then again new idea came to my mind instead of attaching test driver with an already running app instance.
• How about I maximize window frame just before my flutter drive process attach the test driver.
• That's how I came up with currently integrated solution of maximize app instance in test_driver/app.dart before app.main() is called with safety delay.
• If you read this far you must be wondering I could've just start with this solution saved some 2 days worth of work. But the thing that's how most programmers learn. Implementing a real world solution is not as easy like going through the index of a book to find a page number with written solution & not to mention the un valuable experience you gain from these small stressful journeys like. I learned about ENV variables in windows for CMD & PS.
• I hope this poorly written experience can help you in any way.
• windowMode.bat
  • It's is good solution very minimal low size, self compile & required .Net dependency which is already installed to build flutter windows.
  • But it didn't worked well with title argument for some reason.
  • Pid was working solid but in order to get PID I needed to attach test driver with app instance & doing so was messing up test.
• CMDOW
  • Calling this binary without any argument prints the list of all running process with their unique HEX, PID, source & title.
  • Now this solution needed a title or unique HEX in order to maximize a window frame.
  • So I run thing command via dart process class which gave me this unfiltered list.
  • After some parsing I could get the unique HEX & was able to maximize the window frame.