Multiple extensions in marked.use() causing defaults being wrongly overrided

[hyrious]

Marked version:
4.2.2

Describe the bug
As described in the pro doc:

• The renderer and tokenizer options are objects with functions that will be merged into the built-in renderer and tokenizer respectively.

Which means people can use multiple extensions written in this way:

marked.use({ renderer }, { tokenizer })

However this way will cause errors, see reproduction below.

To Reproduce
Install marked locally and run this simple script:

import { marked } from "marked";

marked.use({ tokenizer: {} }, { renderer: {} });
marked.parse(`# hello`);

yields:

TypeError: renderer.text is not a function

Workarounds
You can call marked.use() multiple times to avoid this error.

Expected behavior
No error occurs.

Cause
The last line of marked.use()

marked/src/marked.js

Line 263 in fdbbec6

marked.setOptions(opts);

causes an unexpected renderer or tokenizer object being merged into marked.defaults.

Maybe related(?) #2082

[UziTech]

It looks like the issue is this line

marked/src/marked.js

Line 156 in fdbbec6

const opts = merge({}, ...args);

currently it merges all of the extensions together to get the options. It should be smarter about how it merges the options.

For example, if one extension has async: true set and another one after it has async: false the last extension loaded will override the previous which is what we want for most options but not all. in the case of async if any of the extensions are async: true than async should be true.

It should also disregard the renderer, tokenizer, extensions, and walkTokens options in this merge. They are merged intelligently below this line.

There might be some other options that I am missing.