[Bug report] reloading markdown language will add wrap hook multiple times

[meteorlxy]

Information:

• Prism version: 1.23.0
• Plugins: 'none'
• Environment: Node

Description

The reload logic is described here:

prism/dependencies.js

Lines 383 to 388 in 4e7b2a8

	// add components to reload
	// A component x in `loaded` has to be reloaded if
	// 1) a component in `load` modifies x.
	// 2) x depends on a component in `load`.
	// The above two condition have to be applied until nothing changes anymore.

So the prism-markdown is possible to be reloaded multiple times, and the wrap hook will be added multiple times, too:

prism/components/prism-markdown.js

Line 320 in 4e7b2a8

Prism.hooks.add('wrap', function (env) {

For example:

1. Load markdown and javascript
2. Load jsdoc
   • jsdoc modifies javascript
   • javascript modifies markup
   • markup is depended by markdown
3. So javascript, markup and markdown will also be reloaded

Then, syntax highlighting inside markdown code block will be triggered multiple times.

Example

1. I tried to highlight markdown code:

2. The wrap hooks are:

3. Then the highlighted code:

[RunDevelopment]

Thank you for the comprehensive bug report @meteorlxy!

I made a workaround for now. However, the underlying issue (that the wrap hook function is added multiple times) won't be as easy to solve, so this issue will likely be open for a while.

[meteorlxy]

Yeah I understand the complexity of the underlying issue.

Currently we have to preload all possible languages to avoid such issue.