Optional include inside an include file raises an Unresolved directive

[someth2say]

Say we have a root file with an include directive:

Root

include::test.adoc[]

Then, the test file:

Test

include::test2.adoc[opts=optional]

The expected result was just the text from both files (Root and Test), but I get a Unresolved directive error:

Given the second include is optional, the error should not appear.

[ggrossetie]

This feature is not implemented in a browser because it relies on File.file? which is not available in a browser environment:
https://github.com/asciidoctor/asciidoctor/blob/4d849f85a7e2684c0553c8d9082c5b82ead2cfbc/lib/asciidoctor/reader.rb#L1236-L1245

In other words, we cannot check that the file exists without doing an XMLHttpRequest.
I guess we could reverse the logic and perform an XMLHttpRequest only if optional-option is present since we are already monkey-patching the resolve_include_path:

asciidoctor.js/packages/core/lib/asciidoctor/js/asciidoctor_ext/browser/reader.rb

Lines 3 to 39 in bb39bb2

	def resolve_include_path target, attrlist, attributes
	# NOTE when the IO module is xmlhttprequest, the only way to check if the file exists is to catch a 404 response
	p_target = (@path_resolver ||= PathResolver.new '\\').posixify target
	target_type, base_dir = :file, @document.base_dir
	if p_target.start_with? 'file://'
	inc_path = relpath = p_target
	elsif Helpers.uriish? p_target
	unless (@path_resolver.descends_from? p_target, base_dir) || (@document.attributes.key? 'allow-uri-read')
	return replace_next_line %(link:#{target}[#{attrlist}])
	end
	inc_path = relpath = p_target
	elsif @path_resolver.absolute_path? p_target
	inc_path = relpath = %(file://#{(p_target.start_with? '/') ? '' : '/'}#{p_target})
	elsif (ctx_dir = (top_level = @include_stack.empty?) ? base_dir : @dir) == '.'
	# WARNING relative include won't work in the Firefox web extension (unless we use the second line)
	inc_path = relpath = p_target
	#inc_path = %(#{File.dirname `window.location.href`}/#{relpath = p_target})
	elsif (ctx_dir.start_with? 'file://') || !(Helpers.uriish? ctx_dir)
	# WARNING relative nested include won't work in the Firefox web extension if base_dir is '.'
	inc_path = %(#{ctx_dir}/#{p_target})
	if top_level
	relpath = p_target
	elsif base_dir == '.' || !(offset = @path_resolver.descends_from? inc_path, base_dir)
	relpath = inc_path
	else
	relpath = inc_path.slice offset, inc_path.length
	end
	elsif top_level
	inc_path = %(#{ctx_dir}/#{relpath = p_target})
	elsif (offset = @path_resolver.descends_from? ctx_dir, base_dir) || (@document.attributes.key? 'allow-uri-read')
	inc_path = %(#{ctx_dir}/#{p_target})
	relpath = offset ? (inc_path.slice offset, inc_path.length) : p_target
	else
	return replace_next_line %(link:#{target}[#{attrlist}])
	end
	[inc_path, :file, relpath]
	end

[mojavelinux]

Another idea is to catch the exception when the request for the file fails and suppress the behavior if the optional option is set. I haven't looked to see if there is an opportunity in the code to handle it that way. That's just the idea in theory.

[ggrossetie]

Another idea is to catch the exception when the request for the file fails and suppress the behavior if the optional option is set. I haven't looked to see if there is an opportunity in the code to handle it that way.

Technically it's possible but not practical since we would need to monkey patch at different locations:

• https://github.com/asciidoctor/asciidoctor/blob/1cfe82949c2634e4efa145c23be3014711575708/lib/asciidoctor/reader.rb#L1106-L1107
• https://github.com/asciidoctor/asciidoctor/blob/1cfe82949c2634e4efa145c23be3014711575708/lib/asciidoctor/reader.rb#L1170-L1171
• https://github.com/asciidoctor/asciidoctor/blob/1cfe82949c2634e4efa145c23be3014711575708/lib/asciidoctor/reader.rb#L1194-L1195

Asciidoctor eagerly check that the file exists (using File.file? in resolve_include_path) to avoid additional processing.
We could probably send a HEAD request if optional-option is present... in my opinion that's the lesser evil 😃