[suggestion] Missing commas in array of arrays

[Nondv]

Consider this code:

const arr = [
  [1, 2],
  [3, 4],
  [5, 6]
  [7, 8],
  [9, 0],
]

This is a valid piece of code and it will execute properly. However, it's probably not something that was intended. JS allows accessing elements of an array/object via brackets with a newline character in between.

jshint warns about function invocation on the next line:

const arr = [
  1, 
  2,
  3
  (2 + 2),
  5,
]

produces a warning "Unorthodox function invocation". I think it would be great to have a similar warning for an "unorthodox" object/array accessor usage

UPD. I just checked the code, the warning has nothing to do with the fact that the braces are placed weirdly. It just doesn't like that a number is being invoked as a function. So adding this feature may be potentially hard

[Nondv]

(I ran into this problem at least twice this year and it was really hard to debug)

[jugglinmike]

Thanks for the suggestion! This could make for a good linting rule, though I'd suggest a slightly different heuristic. Instead of considering newlines, JSHint could look for cases where the comma operator is used in a member expression. That would catch mistakes like what you've reported regardless of how folks have formatted their code.

[NumNumNum69420]

h