aligns may include :center

[soutaro]

Context: rbs-gem ships with markdown documentations included in .rbs files, which is imported from RDoc. It uses RDoc::Markup::ToMarkdown formatter.

Problem: I recently found running our translator (rbs annotate) results in an error with Ruby v3_4_0_rc1 as follows:

/Users/soutaro/Developer/rdoc/lib/rdoc/markup/to_rdoc.rb:268:in `block in accept_table': nil is not a symbol nor a string (TypeError)

      h.__send__(a, w)
                 ^^^^
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/to_rdoc.rb:267:in `map'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/to_rdoc.rb:267:in `accept_table'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/table.rb:29:in `accept'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/list_item.rb:53:in `block in accept'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/list_item.rb:52:in `each'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/list_item.rb:52:in `accept'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/list.rb:66:in `block in accept'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/list.rb:65:in `each'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/list.rb:65:in `accept'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/formatter.rb:75:in `block in accept_document'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/formatter.rb:70:in `each'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/formatter.rb:70:in `accept_document'
        from /Users/soutaro/Developer/rdoc/lib/rdoc/markup/document.rb:68:in `accept'
        from /Users/soutaro/Developer/rbs/lib/rbs/annotate/formatter.rb:87:in `translate'
        from ...

(The error is caused by a table included in Kernel.test documentation and other tables.)

Fix: I found that the aligns includes :center, not only nil. Adding a when clause fixes the problem.

I tried to walk through the test code, but couldn't find a good way to implement test for this. Can anyone help me?

[st0012]

Thanks for the fix. I can reproduce the error with tests but it requires updating multiple files. So I'll merge this first and update the tests in a separate PR 😄

PR: #1248