infra(unicorn): prefer-negative-index

[ST-DDT]

Ref: #2439

• Check eslint-plugin-unicorn rules to enable/configure/disable #2439

---

Enables the unicorn/prefer-negative-index lint rule.

[codecov]

Codecov Report

Merging #2512 (390432d) into next (48a7af4) will increase coverage by 0.00%.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##             next    #2512   +/-   ##
=======================================
  Coverage   99.59%   99.59%           
=======================================
  Files        2820     2820           
  Lines      255037   255037           
  Branches     1082     1082           
=======================================
+ Hits       253992   253998    +6     
+ Misses       1017     1011    -6     
  Partials       28       28           

see 1 file with indirect coverage changes

[xDivisionByZerox]

Personally, I find negative indexes quite unintuitive. Usually, a negative index is used to purposefully present an out of bound index. Look at Array.prototype.indexOf: an index of -1 is returned in case the element was not found. Following the negative index logic, the element is actually positioned at array.length - 1, which is not the case.

The rule itself sadly doesn't have any description on WHY you should use it. I'm welcome for anybody providing reasoning on this.

[ST-DDT]

Team Decision

• We accept this.
• Although we might want a code rewrite for the method that is currently affected.
  • e.g. change splice remove + index access -> index access adjusted by removed elements.