I hate bugs in my code. I know you hate bugs in your code too.
When building SharePoint Framework client-side web parts, don't use PropertyPaneTextField to manage values of numeric web part properties. Here is why.
Proper logs are invaluable when your solution isn't working as expected. Here is how you can log information in the SharePoint Framework.
Did you know, that when building SharePoint Framework solutions you can easily include code that will be available only in the debug build?
Errors when using SharePoint Framework dialogs? Here is how to avoid them.