Migrating theme?

It has concerned me for a while.

How to migrate data (example.md) from an old theme to new theme?

Hugo Content Management has a quite powerful feature, the Front Matter. FM allows us to create custom variables in every entry. In the other words, it works as a specific setting for specific entry. And it works great. Thanks to it, Hugo themes are way customizable at the unbelievable level.

However, if we want to change new theme, things are getting complicated from there. If new theme has the same settings like old theme, nothing change. But what if new theme has new settings, and it is required, what will going on? Or legacy settings from old theme could also bug us that make us want to clean theme. Problem’s solved with a small database for just a few files (around 1-3 files.md). But reality does not stop counting under 1 number. That is where the problem comes in, yes, the final boss.

To solve the problem, the only way that I could come with is scrapping every single files and change the setting by our pre-made script. But, before I start to write a program like that, which is a pain in the ass, I would like to know whether we have a kind of program like that. A build-in algorithm or a extend program?

I haven’t run into this issue, but every time someone else has, folks point out that a bunch of text editors have search and replace features that work for entire projects/directories. I believe that is the recommendation.