Lint/SymbolConversion false positive for Hash keys that contain ":"

[s-mage]

Hello. Thanks for your work on the rubocop, it's a great tool.

I've found a false positive for Lint/SymbolConversion cop. It reacts on hash keys like :"one:two" and suggests to replace them with :onetwo. It doesn't fail on var = :"one:two" though.

---

Expected behavior

Don't get triggered on hashes with keys that contain :.

Actual behavior

{ "one:two": "three" }
# [Lint/SymbolConversion] [W]  Unnecessary symbol conversion; use `"onetwo":` instead.

Steps to reproduce the problem

Any hash with key like :"something:something_else" shows the warning.

RuboCop version

->  rubocop -V
warning: parser/current is loading parser/ruby26, which recognizes
warning: 2.6.6-compliant syntax, but you are running 2.6.5.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
1.9.0 (using Parser 3.0.0.0, rubocop-ast 1.4.1, running on ruby 2.6.5 x86_64-darwin19)
  - rubocop-performance 1.9.2
  - rubocop-rails 2.9.1

[s-mage]

Just found another one:

{ "one=": 1 } # [Lint/SymbolConversion] [W]  Unnecessary symbol conversion; use `one=:` instead. ...

> { one=: 1 }
SyntaxError: unexpected ':'

Not sure if it should be a separate issue

[koic]

@s-mage Yeah, maybe a slightly different issue. Can you please open a new another issue?