assert | Provides assertions for unit tests | Assertion library

I'm doing a Group Chat with Firebase and currently I'm using a RecyclerView to display chat messages and I'm having a problem. When you open the app in the fragmented home and you go to chat activity and start chatting (adding elements to recycler view) all goes fine. But, when you go via the NavigationDrawer to another fragment and get back to the chat fragment using again this Navigation Drawer. When you add one element in the chat it appears all in the blank it just displays the last message. Anybody knows why does this happens?

Here I leave the RecyclerView Adapter Code:

So I am relatively new to programming, and I have been working on this task app, where I want to save the data such as task name and more, given by the user. I am trying to accomplish this using Room. Now, initially, when I tried to do it, the app would crash since I was doing everything on the main thread probably. So, after a little research, I came to AsyncTask, but that is outdated. Now finally I have come across the Executer. I created a class for it, but I am a little unsure as to how I can implement it in my app. This is what I did :

Entity Class :

My classes are Hooks for setup and test. I try to click on cookie pop-up, using WebdriverWait, but don't work. I have no idea why.

I am a beginner with selenium and automation testing and I am writing a selenium script using java, TestNG, and maven. When I write everything in one class, all works fine, but I want to have a package for all objects, a package for tests, and Hooks with the main setting.

Given I have the following TestFixture with TestCase arguments as pairs of decimal, int (because C# doesn't support decimal directly in an attribute).

I have sample tests used from scalatest.org site and maven configuration again as mentioned in reference documents on scalatest.org, but whenever I run mvn clean install it throws the compile time error for scala test(s).

Sharing the pom.xml below

I was taking freecodecamp.org course on JavaScript data structures, going through the RegExp chapter. I then came across the following assertion:

"The regular expression /(?=\w{3,6})(?=\D*\d)/ will check whether a password contains between 3 and 6 characters and at least one number". (Here "check" meaning that regExp.test(password) returns true)

This seems odd to me. First of all, looking around in Stack Exchange, I found in this post that states that A(?=B) is the definition of positive lookahead, and it makes no mention that A (the preceeding expression in the parenthesis) is optional. So, shouldn't freecodecamp's example have an expression before the first lookahead?

I believe that this another example is quite similar to the previously mentioned, but simpler so I will mention it in case the explanation is simpler, too:

Why does (?=\w)(?=\d), when checked against the string "1", returns true?, Shouldn't it look for an alphanumeric character followed by a numeric character?

PS: After a thought, I hypothesized that my first example checks both lookahead patterns independently (i.e. first it checks whether the string is made of three to six characters, returns true, then checks whether there is an alpha numeric character, and finally since both searchings returned true, the whole regexp test returns true). But this doesn't seem to be coherent with the definition mentioned in the post I've linked. Is there a more general definition or algorithm which the computer "internally" uses to deal with lookaheads?

I am trying to write a unit test code for my Spark-Scala notebook using scalatest.funsuite but the notebook with test() is not getting executed in databricks. Could you please let me know how can I run it?

Here is the sample test code for the same.

I am trying to create a snackbar on the click of a button in flutter, but getting exception that No ScaffoldMessenger widget found. The same code seems to work properly in the Flutter sample mentioned in docs. Am I missing something here? Thanks.

Here's my main.dart file