gitbook-plugin-uml not work properly

Summary

gitbook-plugin-uml, a plugin that renders plantuml diagram, does not work properly on HonKit. This is a problem of not the plugin but HonKit because it works on gitbook-cli.

• HonKit version: 3.5.0

Step to reproduce

1. npm init --yes
2. npm install honkit --save-dev
3. npx honkit init
4. npm install gitbook-plugin-uml --save-dev
5. edit book.json
6. edit README.md
7. npx honkit serve

• Link to code example:

book.json

{
    "plugins": ["uml"]
}

README.md

```uml
@startuml

/'
  Comment
 '/

	Class Stage
	Class Timeout {
		+constructor:function(cfg)
		+timeout:function(ctx)
		+overdue:function(ctx)
		+stage: Stage
	}
 	Stage <|-- Timeout

@enduml
```

I guess a plantuml source including special characters like / failed to be rendered.

Expected results

The diagram would be rendered.

Actual results

An image that says there is an error appears.

$ npx honkit build --log=debug
debug: readme found at README.md 
debug: summary file found at SUMMARY.md 
debug: cleanup folder "/home/elferia/honkit-uml/_book" 
info: 6 plugins are installed 
info: 6 explicitly listed 
info: plugin "uml is loaded
info: plugin "highlight is loaded
info: plugin "search is loaded
info: plugin "lunr is loaded
info: plugin "fontsettings is loaded
info: plugin "theme-default is loaded
info: found 1 pages 
info: found 5 asset files 
debug: calling hook "config" 
debug: calling hook "init" 
warn: "book" property is deprecated, use "this" directly instead 
debug: copy assets from theme /home/elferia/honkit-uml/node_modules/@honkit/honkit-plugin-theme-default/_assets/website 
debug: copy resources from plugin /home/elferia/honkit-uml/node_modules/gitbook-plugin-fontsettings/assets 
debug: copy resources from plugin /home/elferia/honkit-uml/node_modules/gitbook-plugin-lunr/assets 
debug: copy resources from plugin /home/elferia/honkit-uml/node_modules/gitbook-plugin-search/assets 
debug: copy resources from plugin /home/elferia/honkit-uml/node_modules/gitbook-plugin-highlight/css 
debug: copy asset "assets/images/uml/65902d3d2519f65a9fe3a4e91401058002521178.svg" 
debug: copy asset "assets/images/uml/67802308346393fc5d1d4a0e1efc555904eb64ba.svg" 
debug: copy asset "assets/images/uml/c3c103d2bede49665226ff9cc9acb9a330da3174.svg" 
debug: copy asset "package-lock.json" 
debug: copy asset "package.json" 
debug: calling hook "finish:before" 
debug: calling hook "finish" 
debug: write search index 
info: >> generation finished with success in 0.4s !

[elferia]

Hi

Workaround 2 looks better so I tried, but not worked. Diagrams are ignored, even error images are not rendered. I guess ansanloms/honkit-plugin-uml does not support syntax like

```uml
@startuml

as well as gitbook-plugin-puml-aleung, but not tested.

So I tried Workaround 1, then the diagrams rendered successfully. But other problems occurred. It it not proper to discuss other problems here, but I would like to report. For example, markdown as below will not be rendered as expected:

~~~md
 ```mermaid
 graph TD;
   A-->B;
   A-->C;
   B-->D;
   C-->D;
 ```
~~~

I would like to report this as another issue and hope to be fixed, but I cannot afford. I will try HonKit again in the future. Thank you.

[azu]

Thanks to confirm! 🎉