Incorrect code formatting result (flipped conditional logic)

[willhoney7]

Okay, I know this is strange code, but the standard formatter completely flipped the conditional logic. I did a full codebase-wide formatting update and we started getting errors from this.

Version: 1.54.0

Input

class FormatTest
  def payload
    {}
  end

  def check_format
    unless payload.is_a?(Array) &&
           !payload.blank? &&
           payload.first.try(:[], :effective_date);

           fail UnprocessableError
    end
  end
end

The standard report

standard: Use Ruby Standard Style (https://github.com/standardrb/standard)
  format_test.rb:1:3: Layout/InitialIndentation: Indentation of first line in file detected.
  format_test.rb:1:13: Layout/IndentationWidth: Use 2 (not 4) spaces for indentation.
  format_test.rb:3:1: Layout/DefEndAlignment: `end` at 3, 2 is not aligned with `def` at 1, 0.
  format_test.rb:5:1: Layout/IndentationConsistency: Inconsistent indentation detected.
  format_test.rb:6:5: Style/IfWithSemicolon: Do not use `if payload.is_a?(Array) &&            !payload.blank? &&            payload.first.try(:[], :effective_date);` - use a ternary operator instead.
  format_test.rb:6:3: Style/TernaryParentheses: Use parentheses for ternary expressions with complex conditions.
  format_test.rb:7:3: Layout/MultilineOperationIndentation: Use 2 (not 7) spaces for indenting an expression spanning multiple lines.
  format_test.rb:7:12: Layout/MultilineOperationIndentation: Use 4 (not 7) spaces for indenting a condition in an `unless` statement spanning multiple lines.
  format_test.rb:8:3: Layout/MultilineOperationIndentation: Use 2 (not 7) spaces for indenting an expression spanning multiple lines.
  format_test.rb:8:12: Layout/MultilineOperationIndentation: Use 4 (not 7) spaces for indenting a condition in an `unless` statement spanning multiple lines.
  format_test.rb:8:51: Style/Semicolon: Do not use semicolons to terminate expressions.
  format_test.rb:10:5: Layout/IndentationWidth: Use 2 (not 7) spaces for indentation.
  format_test.rb:12:6: Layout/TrailingEmptyLines: Final newline missing.
standard: Run `standardrb --fix` to fix up to 13 problems.

Fix Output

class FormatTest
  def payload
    {}
  end

  def check_format
    (payload.is_a?(Array) &&
      !payload.blank? &&
      payload.first.try(:[], :effective_date)) ? fail(UnprocessableError) : nil
  end
end

[jasonkarns]

What does standard -V give you?

[jasonkarns]

I've been able to whittle this down to a more minimal repro, that violates only a single cop. And whose autocorrection is faulty.

$ ./exe/standardrb -V
Standard version: 1.54.0
RuboCop version:  1.84.2 (using Parser 3.3.10.2, rubocop-ast 1.49.0, analyzing as Ruby 3.0, running on ruby 3.4.8) [arm64-darwin25]

class FormatTest
  def truthy
    true
  end

  def run
    unless truthy; fail("should not error"); end
  end
end

FormatTest.new.run

# runs clean
$ ruby bug.rb 

# single cop violation
$ ./exe/standardrb bug.rb 
standard: Use Ruby Standard Style (https://github.com/standardrb/standard)
  bug.rb:7:5: Style/IfWithSemicolon: Do not use `if truthy;` - use a ternary operator instead.
standard: Run `standardrb --fix` to potentially fix one problem.

# autocorrected
$ ./exe/standardrb --fix bug.rb 

# now behaves differently
$ ruby bug.rb 
bug.rb:7:in 'FormatTest#run': should not error (RuntimeError)
	from bug.rb:11:in '<main>'

This looks like a bug upstream in the autocorrection of Style/IfWithSemicolon. https://docs.rubocop.org/rubocop/latest/cops_style.html#styleifwithsemicolon

This will need opened and tracked with rubocop.

[willhoney7]

Thank you! I've opened rubocop/rubocop#15034 in rubocop.

[willhoney7]

Looks like this was fixed in 1.86 in rubocop. Can we cut a release of standard with that when possible?

Thanks!