Fix: yoda exceptRange false positives on empty string property names

[mdjermanovic]

What is the purpose of this pull request? (put an "X" next to item)

[X] Bug fix

This small bug fix can produce only fewer warnings.

Tell us about your environment

• ESLint Version: 6.1.0
• Node Version: 10.16.0
• npm Version: 6.9.0

What parser (default, Babel-ESLint, etc.) are you using?

default

Please show your full configuration:

Configuration

module.exports = {
  parserOptions: {
    ecmaVersion: 2015,
  },
};

What did you do? Please include the actual source code causing the issue.

/*eslint yoda: ["error", "never", { "exceptRange": true }]*/

if (0 < x[``] && x[``] < 100) {} // backticks

What did you expect to happen?

No errors.

What actually happened? Please include the actual, raw output from ESLint.

1 error

What changes did you make? (Give an overview)

getStaticPropertyName() return value is now explicitly compared to null, because it can be a valid empty string value.

Is there anything you'd like reviewers to focus on?

[platinumazure]

Changes LGTM, thanks!

Just for my understanding, all of the invalid test cases would pass even with the current rule code, right?

[mdjermanovic]

Changes LGTM, thanks!

Just for my understanding, all of the invalid test cases would pass even with the current rule code, right?

Yes! Those are just regression tests for this PR.

[platinumazure]

I've reproduced here. Marking as accepted.

[kaicataldo]

LGTM. Thanks for working on this!

[platinumazure]

Merged. Thanks for contributing!