~~ arrayPattern.trailingCommas: always ~~
== should format with trailing commas when multiline ==
function test([
    a    ,
    b
]) {
}

[expect]
function test([
    a,
    b,
]) {
}

== should format with trailing commas when single line ==
function test([a, b]) {
}

[expect]
function test([a, b,]) {
}
