I'm interested your book, I'm waiting for a professional book talk about Emacs Lisp and Emacs plugins development.
For environment isolation, maybe put plugin source at /tmp and call emacs with -Q option is best practices. In my mind, I think the plugin develop workflow is:
Real environment:
Write, Modify code
Virtual environment:
Run, test, debug plugin, when debug, real environment using emacs lisp debugger attach virtual environment for debug.

---Original---
From: "Marcin Borkowski"<mbork@mbork.pl&gt;
Date: Fri, Nov 29, 2019 19:16 PM
To: "Anonymous"<c4droid@foxmail.com&gt;;
Cc: "emacs-devel"<emacs-devel@gnu.org&gt;;
Subject: Re: Some ideas with Emacs



On 2019-11-29, at 10:05, Anonymous <c4droid@foxmail.com&gt; wrote:

&gt; Hi, I'm a user and a fanatical fans for Emacs. I'd like to share a few ideas for about Emacs Lisp.
&gt; Emacs Lisp is powerful, it's undeniable.&amp;nbsp;But when I studied Emacs Lisp, I found that there were too few examples of function use in the tutorial.&amp;nbsp;Also when using Emacs Lisp for Emacs plugin development and configuration,&amp;nbsp;Sometimes you write your own plugins will affect the configuration you write, so I'd like to make a few ideas for Emacs Lisp:
&gt; First, suggest to add more examples of functions in the tutorial, most for Emacs Lisp Reference Manual, which can lower the learning threshold.

I had a plan to write an intermediate book on Elisp, but Real Life™
intervened.&nbsp; I still have the stuff I managed to write, and if I live
long enough, I'm going to get back to this project (the current plan is
late 2020 - I'm finishing work on another book now, which is long
overdue, and I cannot postpone it more because it is a joint work with
two other people).&nbsp; Would you be interested?&nbsp; What would you like to see
in such a book?&nbsp; (The idea was - and is - to start approximately where
Robert Chassell's "Elisp Intro" ends.)

&gt; Second, in developing the Emacs plugins, create a virtual environment, like Python virtualenv, so that we can test the plugin in the virtual environment so that we do not need to affect the configuration outside the virtual environment. That's can implement plugin development environment and configuration isolation.
&gt;
&gt; Although my suggestion may be a little trivial and even useless.&amp;nbsp;But if my suggestions can help beginners like me go further, I think it's worth it.

AFAIK, this is _far_ from trivial.&nbsp; However, you can always start
a fresh Emacs instance with -Q.&nbsp; For more advanced configs, you may
start a fresh Emacs instance with the config directory in /tmp or
whatever.&nbsp; (Shameless plug: I blogged about it a few weeks ago, see
http://mbork.pl/2019-11-04_Starting_Emacs_with_custom_configuration_directory.)

Now that I think of it, we could even have an Emacs command to start
a fresh Emacs instance with a given file already loaded.&nbsp; WDYT?

Hth,

--
Marcin Borkowski
http://mbork.pl
i