Overhaul coverage report

[st0012]

Summary

• Make the coverage result more concise and useful
• Make the output less confusing for C source files
• Simplify implementation by decoupling it from RDoc's markup elements

Before (Ruby pseudo-code format)

class RDoc::Generator::Darkfish # is documented

    # in file lib/rdoc/generator/darkfish.rb:744
    def generate_ancestor_list(ancestors, klass); end

    # in file lib/rdoc/generator/darkfish.rb:762
    def generate_class_link(klass, rel_prefix); end

end


class RDoc::Markup::ToAnsi # is documented

    # in file lib/rdoc/markup/to_ansi.rb:29
    ANSI_STYLE_CODES_OFF = nil

    # in file lib/rdoc/markup/to_ansi.rb:59
    def add_text(text); end

    # in file lib/rdoc/markup/to_ansi.rb:131
    def calculate_text_width(text); end

end

After (file-centric format)

lib/rdoc/generator/darkfish.rb:
  Method:
    RDoc::Generator::Darkfish#generate_ancestor_list                 lib/rdoc/generator/darkfish.rb:744
    RDoc::Generator::Darkfish#generate_class_link                    lib/rdoc/generator/darkfish.rb:762

lib/rdoc/markup/to_ansi.rb:
  Constant:
    RDoc::Markup::ToAnsi::ANSI_STYLE_CODES_OFF lib/rdoc/markup/to_ansi.rb:29
  Method:
    RDoc::Markup::ToAnsi#add_text             lib/rdoc/markup/to_ansi.rb:59
    RDoc::Markup::ToAnsi#calculate_text_width lib/rdoc/markup/to_ansi.rb:131

C source file output (Ruby's object.c)

object.c:
  Class:
    Refinement

No more class Refinement ... end pseudo-code that makes it look like the C file is being treated as a Ruby script.

Accuracy verification

Coverage metrics are unchanged for projects other than RDoc itself:

Project	Branch	Master
IRB	117 items, 40 undoc (65.81%)	117 items, 40 undoc (65.81%)
Ruby	12110 items, 1472 undoc (87.84%)	12110 items, 1472 undoc (87.84%)

[matzbot]

🚀 Preview deployment available at: https://8ac7ce2e.rdoc-6cd.pages.dev (commit: 793635c)