Idempotency issue with let … in

[Smaug123]

Issue created from fantomas-online

Code

module Foo =
    let bar () =

        let rec loop () = async {
            let! msg = thing
            match msg with
            | Message ->
                let passThrough () = ()
                let runStep = baz
                match thing with
                | Boo ->
                    stepLog.LogInformation ("Thing thing thing {Foo} thing", (let (DuCase a) = ThingThingThing.go options |> BlahBlah foo in a))
        }
        ()

Result

module Foo =
    let bar () =

        let rec loop () =
            async {
                let! msg = thing

                match msg with
                | Message ->
                    let passThrough () = ()
                    let runStep = baz

                    match thing with
                    | Boo ->
                        stepLog.LogInformation (
                            "Thing thing thing {Foo} thing",
                            (let (DuCase a) =
                                ThingThingThing.go options |> BlahBlah foo in

                             a)
                        )
            }

        ()

Problem description

This is actually an idempotency issue, but I can't use that button for this because GitHub complains the URI is too long. A reformat adds an extra newline.

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 04/05/2021 16:09:34 - 31922c0

    { config with
                MaxLineLength = 100
                SpaceBeforeUppercaseInvocation = true
                SpaceBeforeClassConstructor = true
                SpaceBeforeMember = true
                SpaceBeforeColon = true
                SpaceBeforeSemicolon = true
                MultilineBlockBracketsOnSameColumn = true
                NewlineBetweenTypeDefinitionAndMembers = true
                KeepIfThenInSameLine = true
                AlignFunctionSignatureToIndentation = true
                AlternativeLongMemberDefinitions = true
                MultiLineLambdaClosingNewline = true
                KeepIndentInBranch = true }

_{Did you know that you can ignore files when formatting from fantomas-tool or the FAKE targets by using a .fantomasignore file?}