Suppose you wanted to adjust the base HREF in an index.html file using a regular expression, as part of a build process you are cobbling together using NPM scripts. How could you do that? Here’s one answer, though this only works if the sed command line tool is available (as it will be almost always on Linux or Mac, and only if you install it on Windows):
"add-base-url": "sed -i.bak -e 's/\\\"\\\/\\\"/\"\\\/some-base-url-here\"/' dist/index.html",
Unfortunately, I have begged a question. (In the traditional sense and that I assumed an answer to a question, not the modern repurposed thing of the phrase). Is it actually a good idea to use the combination of a regular expression and a script written in a JSON file, to do anything at all?
Looking at the multiple levels of \\/\/\/\\\///\// escaping above, I think the answer to this question is clearly no. It would be better to use some other means for this adjustment. On other projects we have done the same manipulation using a tool that manipulates the HTML structure. It is more verbose but vastly easier to understand.
(Incidentally, I used to do things somewhat like the above to adjust the base URLs for Angular applications. This is not necessary anymore if using Angular CLI – it has an option built in, –base-href.)