Syntax highlighting of injected language not shown in Preview

[ThFriedrich]

Thanks @mjbvz for this super helpful example.
Running the example as it is I get the following behavior:

It seems within the md.-file the injected Syntax is highlighted but in the Preview, it isn't. Is that by design? Is it possible to transfer the Syntax highlighting functionality into the Preview as well?

My Setup:
Version: 1.46.1
Electron: 7.3.1
Chrome: 78.0.3904.130
Node.js: 12.8.1
V8: 7.8.279.23-electron.0
OS: Linux x64 5.3.0-61-generic

[mjbvz]

This is a known limitation. The markdown preview uses highlight.js for highlighting, not VS Code's highlighting

[mjbvz]

Closing this as this is current design of VS Code.

microsoft/vscode#56356 would let the preview use VS Code's built-in highlighter instead

[tjpalmer]

For those finding this in the future, the mermaid markdown example also by @mjbvz shows where to plug in custom syntax highlighting in markdown preview. And vscode-textmate can be used to adapt tokens to hljs class names. It would be nice if vscode did this automatically, but it's possible to wire up manually at this point.

[ThFriedrich]

Thanks @tjpalmer
I had reached a very similar conclusion back then, indeed using vscode-textmate and vscode-oniguruma. You can check the StackOverflow Question and my implementation for the details.