Comment after Or operator lost

[nojaf]

Issue created from fantomas-online

Code

let f x =
    a
    || // other case
    match n with
    | 17 -> false
    | _ -> true

Result

let f x =
    a
    || match n with
       | 17 -> false
       | _ -> true

Problem description

Trivia is assigned to SynExpr_App while SynExpr_Ident (||) is the better candidate.

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 09/04/2020 11:05:32 - d3828b0

Default Fantomas configuration

[nojaf]

Related:

let r =
    {| Foo =
           a
           && // && b
           c
       Bar = """
Fooey
""" |}

[nojaf]

Possible fix in Trivia.fs:

let inline isMainNodeFor nodeType (node: TriviaNodeAssigner) =
    match node.Type with
    | MainNode (t) when (t = nodeType) -> true
    | _ -> false

let private findLastNodeOnLine (nodes: TriviaNodeAssigner list) lineNumber: TriviaNodeAssigner option =
    nodes
    |> List.filter (fun tn -> tn.Range.EndLine = lineNumber)
    |> List.sortByDescending (fun tn -> tn.Range.EndColumn, tn.Range.StartColumn)
    |> fun candidates ->
        match candidates with
        | app::ident::_ when (app.Range.End = ident.Range.End
                              && isMainNodeFor SynExpr_App app
                              && isMainNodeFor SynExpr_Ident ident) ->
            Some ident
        | h::_ -> Some h
        | [] -> None