unicorn/require-array-join-separator Style
What it does
Enforce using the separator argument with Array#join()
Why is this bad?
It's better to make it clear what the separator is when calling Array#join(), instead of relying on the default comma (',') separator.
Example
Examples of incorrect code for this rule:
javascript
foo.join();
Examples of correct code for this rule:
javascript
foo.join(",");