Comments are removed before and after empty array literals

[bamarsha]

Issue created from fantomas-online

Code

module Foo

let x = [||] // After empty array

let y =
    // Before empty array
    [||]

Result

module Foo

let x = [||]

let y = [||]

Problem description

Fantomas removes comments that occur before or after an empty array literal. The formatted code should keep both comments. Non-empty array literals work correctly, though.

Extra information

• The formatted result breaks by code.
• The formatted result gives compiler warnings.
• I or my company would be willing to help fix this.

Options

Fantomas Master at 12/09/2020 20:05:59 - f93af00

Default Fantomas configuration

[nojaf]

Hello Sarah,

Thanks for taking the time to report this issue!
At first glance, this seems like a Trivia bug. The code comments are detected from the F# tokens but not printed out in CodePrinter.

Maybe SynExpr_ArrayOrList is missing in

fantomas/src/Fantomas/CodePrinter.fs

Line 2693 in 5a66ce5

|> (match synExpr with

.

Checkout this video for some additional context.

Are you interested in submitting a PR?

[c-rindi]

Thank you for submitting the PR @SamarSha!