Adding multiple syntax group to a syntax region

Question

I’m writing a syntax file for Bats. I started my syntax file by loading the bash syntax:

let g:is_bash=1
runtime! syntax/sh.vim
unlet b:current_syntax

I then defined the Bats custom keywords:

syntax match batsTestKeyword "\v\@test"
syntax keyword batsFunction load setup teardown run skip assert_success assert_failure assert_output

Finally, I’m trying to create a region that contains both the Bash syntax and the batsFunction keywords:

syntax region batsTestBlock start='{' end='}' contains=@bash, batsFunction

However when looking at a test file only the Bash syntax is highlighted and not my custom syntax.

Any idea why my custom syntax is not included in the region?

Note: The keyword are linked as follows:

highlight default link batsTestKeyword  Identifier
highlight default link batsFunction Function

Answer 1

From what I understand from your comments, the problem is that the @test { } group to include bash syntax. One way I found to achieve this is by using :syntax include (:help :syn-include):

let g:is_bash=1

syntax include @BASH syntax/sh.vim
unlet b:current_syntax

runtime! syntax/sh.vim
unlet b:current_syntax

syntax match batsTestKeyword "\v\@test"
syntax keyword batsFunction load setup teardown run skip assert_success assert_failure assert_output

syntax region batsTestBlock start='{' end='}' contains=@BASH,batsFunction

highlight default link batsTestKeyword Identifier
highlight default link batsFunction Function

At the top, we include the bash syntax twice, once as the @BASH group, and once in the global namespace. The contained group can be added to the contains= list. You'd done that, actually, I assume from looking at some example, but you hadn't included the bash syntax group as that name.

I admit that syntax highlighting is not my strong suite, so there may be a better way of doing this, but this seems to work, in my experiments.