Can't form Range with upperBound < lowerBound

[andrewconlan]

Seem to be running into an issue when adding a header to a list "* #" or quote "> #", then checking the range for that header:

Fatal error: Can't form Range with upperBound < lowerBound

I've added a test project, to show it happening test.zip

[mattt]

Thanks so much for opening this issue and providing a reproducible test case, @andrewconlan. This looks to be a bug in cmark, as cmark_node_get_start_column is reporting a position after cmark_node_get_end_column. I'll investigate this some more and open some issues / PRs in that project.

In the meantime, I can think of a few possible workarounds:

• Replace the range property with constituent startPosition and endPosition properties, adding a note about there being no guarantees for those to form a valid range
• Make the range property optional; if no valid range can be formed, it returns nil.
• Modify the reported positions to ensure a valid range is formed; in your example, the range would have a column range of 3...3.

Of these options, I'm leaning on #3, because that would provide a fix without changing the public API. Do you have any strong feelings about the best way to resolve this?

[andrewconlan]

Yep I think number #3 sounds like a good solution until it's resolved in cmark, I'm using the project to add attributes to a UITextView as the user types and it's working really well, thanks again for the project, it's excellent

[mattt]

Thanks again for reporting this, @andrewconlan. The fix in #2 is now merged and available in version 0.2.2.