YARD fails to recognize empty symbol (:"") on Ruby 2.6.3, which causes build failures

[skalee]

Something has changed in Ruby 2.6.3. In the result, two tests fail.

Steps to reproduce

1. Switch to Ruby 2.6.3.
2. Run bundle exec rspec or bundle exec rake.

Actual Output

RSpec Failures

  1) YARD::Handlers::Ruby::ConstantHandler documents block for Struct.new if present
     Failure/Error: expect(obj.constants[1].value).to eq ':""'

       expected: ":\"\""
            got: ":\"\\n\""

       (compared using ==)
     # ./spec/handlers/constant_handler_spec.rb:39:in `block (2 levels) in <top (required)>'
     # ./spec/spec_helper.rb:127:in `block (2 levels) in <top (required)>'

  2) YARD::Templates::Helpers::MethodHelper#format_constant displays correctly constant values which are quoted symbols
     Failure/Error: expect(format_constant(foo)).to eq ":&quot;&quot;"

       expected: ":&quot;&quot;"
            got: ":&quot;\\n&quot;"

       (compared using ==)
     # ./spec/templates/helpers/method_helper_spec.rb:102:in `block (3 levels) in <top (required)>'
     # ./spec/spec_helper.rb:127:in `block (2 levels) in <top (required)>'

Expected Output

All tests should pass.

Possible causes

According to release notes, not much has changed:

This release adds support for New Japanese Era “令和” (Reiwa). It updates the Unicode version to 12.1 beta and updates the date library.

Full changelog:

• ruby/ruby@v2_6_2...v2_6_3

Main suspect:

• ruby/ruby@8bf06cb which is supposed to fix https://bugs.ruby-lang.org/issues/15670

Secondary suspect:

• ruby/ruby@69ec393

---

I have read the Contributing Guide.

[skalee]

More details:

In ./spec/handlers/constant_handler_spec.rb:38, source range of s(:string_content, ) which represents the empty string in symbol definition :'' is 417..417, whereas it should be 416..415. Note that both boundaries are incorrect.

Non-empty quoted symbols (e.g. :'42') are recognized as intended.

[lsegal]

This was fixed in #1256. Thanks for reporting!