Dart and Flutter Waiting for another flutter command to release the startup lock…
I opened VSCode and tried to start a mobile emulator but the device list didn't appear on the command palette. I ran Run...
Dart and Flutter 
JavaScript/TypeScript How to write annoying unit tests
A unit test should be clear enough. To make it concise, the tests are refactored. It looks good at first but some of them trouble us as the software grows. Let's understand those ways to cause problems.
JavaScript/TypeScript TypeScript How to refactor a function to use named parameters
TypeScript and JavasScript don't offer named parameters. How can we do a similar thing? Is there are any to refactor the code to apply the technique?
Dart and Flutter Flutter Scrolling while dragging an item
Drag and drop are often used when we want to move an item. If the list is long it's necessary to be scrollable while dra...
Dart and Flutter Flutter How to write unit test for thrown exception
I didn't know how to write unit test for a function that throws an exception. Therefore. I looked into the solution and ...
Dart and Flutter Dart Compare two objects – how to deep equal
This article explains how to compare two objects in Dart. How can we implement if we want to do deep equal? What is the good way to override hashCode and == operator?
Dart and Flutter Flutter Provider example ChangeNotifierProvider and Consumer
I have used only setState in order to update the view but I faced a problem while I developed my own package grouped exp...
Dart and Flutter Flutter Draggable Expansion Tile
When we want to make a widget draggable, Draggable class is useful and easy to to use. An Expansion Tile has children. H...
Dart and Flutter Flutter Dynamic expansion tile for group data
I needed a expansion tile for grouping data. I wanted to show item list like a folder structure on VS Code. Top parents ...
Dart and Flutter Build error after upgrading Flutter
When I upgraded Flutter from 2.2.3 to 2.5.0 debug console showed a lot of build errors. I didn't understand what caused ...