Autocorrect produces invalid syntax for Style/TrailingCommaIn(Array|Hash)Literal and Layout/Multiline(Array|Hash)BraceLayout

[labocho]

In some case below, auto-correction may produce invalid syntax.

• Style/TrailingCommaInArrayLiteral or Style/TrailingCommaInHashLiteral is configured with EnforcedStyleForMultiline: consistent_comma.
• Enable Style/TrailingCommaIn(Array|Hash)Literal and Layout/Multiline(Array|Hash)BraceLayout at same time.

---

Expected behavior

Do not change semantics on auto-correct.

Actual behavior

Change semantics on auto-correct.

Steps to reproduce the problem

# .rubocop.yml
Style/TrailingCommaInArrayLiteral:
  EnforcedStyleForMultiline: consistent_comma

Style/TrailingCommaInHashLiteral:
  EnforcedStyleForMultiline: consistent_comma

Array literal

# multi_line_array.rb
[ 1,
  2
].to_s

rubocop --only=Style/TrailingCommaInArrayLiteral,Layout/MultilineArrayBraceLayout -a multi_line_array.rb produces invalid source as below.

[ 1,
  2],.to_s

Hash literal

# multi_line_hash.rb
{ foo: 1,
  bar: 2
}.to_s

rubocop --only=Style/TrailingCommaInHashLiteral,Layout/MultilineHashBraceLayout -a multi_line_hash.rb produces invalid source as below.

{ foo: 1,
  bar: 2},.to_s

RuboCop version

$ rubocop -V
0.74.0 (using Parser 2.6.3.0, running on ruby 2.6.2 x86_64-darwin18)

[koic]

Dup #6498.

[buehmann]

I understand what is happening and have a fix for it. @koic How do I best add a spec that verifies that these pairs of cops work correctly together? Is there a best practice for this?

[koic]

@buehmann Tests for auto-correction with multiple cops can be written to spec/rubocop/cop/layout/indentation_width_spec.rb. The following address may be helpful.
https://github.com/rubocop-hq/rubocop/pull/6866/files#diff-0e7dbdd6e99e0defc2bab2cb544b42da

[labocho]

Thanks!