Tab-indented code block rendering issue

[katwalk]

I’m using the Markdown lexer and seeing flaky rendering for tab-indented code blocks.

Take a look at this screen recording. As I type, the code block highlighting randomly drops out.
https://streamable.com/pv4t27

My questions:
Is this a lexer bug?
If not, the trigger rules for tab-indented code blocks are really confusing.

[main Alexey]

it has the reason.

a. regex for 'codeblock' rule is

Code: Select all

      DisplayName = 'Codeblock indented'
      Expression = '(?<=^$\n)(^(\x20{4,}|\x09{1,})[^`<>:\n\r].*$\n)+ ^$'

so you need empty line above code + empty line below.

b. coloring changes when edition touches 1st line of block.

[katwalk]

Thank you for the explanation, I finally understand.