False positive for Style/HashAsLastArrayItem when the array is implicit

[dvandersluis]

Style/HashAsLastArrayItem detects and corrects hashes in an implicit array (such as when passing multiple values to a setter), resulting in a syntax error.

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Expected behavior

The following is a common line of code in Rails projects:

config.cache_store = :redis_cache_store, { url: ENV['REDIS_URL']  }

It should not register an offense, as the braces are necessary syntax.

Actual behavior

Rubocop registers an offense:

bundle exec rubocop bug.rb -A --only Style/HashAsLastArrayItem
bug.rb:1:42: C: Style/HashAsLastArrayItem: Omit the braces around the hash.
config.cache_store = :redis_cache_store, { url: ENV['REDIS_URL'] }
                                         ^^^^^^^^^^^^^^^^^^^^^^^^^

And corrects to:

config.cache_store = :redis_cache_store,  url: ENV['REDIS_URL'] 

Which is a syntax error:

$ ruby bug.rb
bug.rb:1: syntax error, unexpected tLABEL
...ore = :redis_cache_store,  url: ENV['REDIS_URL']

RuboCop version

$ rubocop -V
0.91.0 (using Parser 2.7.1.4, rubocop-ast 0.4.0, running on ruby 2.6.2 x86_64-darwin18)