Thanks from 2021, to know the concept behind the code is really important!
Got it, thank you so much for the explanation.
Just to confirm, even though the test runs on Github CI, it still uses the test DATABASE instead of production DATABASE right? So the main purpose here is to confirm the rest of the project members' code under testing within the whole project? The reason I ask this question is that before pushing the code to GitHub, I will definitely test it locally, so if it just for my own benefit, it won't need to be tested again on GitHub CI. Or maybe there are some others reasons which make the GitHub CI test necessary.
I am sorry if I asked any low-level questions, I am a newbie of Ruby on Rails and GitHub CI, I am really curious about this question, thanks for your time.
Have no idea what happened yet, I didn't set RAILS_MASTER_KEY env var but just commented on the RAILS_MASTER_KEY line in the <.rbenv-vars> file.
Now the production site works.