Extra whitespace added to beginning or end of some lines

[bdube]

The formatting of this line
(fun () -> parser.ParseCommandLine [||] |> ignore)
is left unchanged, but fantomas 2.8.1 adds a single space to the end of the line.

Other reformatted sections also end up with a single space added to the end of some lines.

I'll try to describe this issue better by writing a failing test case. Also I see that 2.9.0 was just released, so I'll check that version as well.

Edit: I see the same behavior with 2.9.0. I'll work on a test case.

[bdube]

[<Test>]
let ``should not confuse me with an extra space at end of line v1``() =
    let codeSnippet = """(fun () -> parser.ParseCommandLine [||] |> ignore)"""

    formatSourceString false codeSnippet config
    |> should equal """(fun () -> parser.ParseCommandLine [||] |> ignore)
"""

[<Test>]
let ``should not confuse me with an extra space at end of line v2``() =
    let codeSnippet = """let ``should not extrude without positive distance`` () =
    let args = [| "-i"; "input.dxf"; "-o"; "output.pdf"; "--op"; "extrude"; |]
    (fun () -> parseCmdLine args |> ignore)
    |> should throw typeof<Argu.ArguParseException>"""

    formatSourceString false codeSnippet config
    |> should equal """let ``should not extrude without positive distance``() =
    let args = [| "-i"; "input.dxf"; "-o"; "output.pdf"; "--op"; "extrude" |]
    (fun () -> parseCmdLine args |> ignore)
    |> should throw typeof<Argu.ArguParseException>
"""

Note, the first test passes when testing with formatSourceString, but it's an actual example of a line that fantomas (2.8.1|2.9.0) adds an extra space to my code.

The second test fails and shows the extra space I am seeing with fantomas (2.8.1|2.9.0).

[bdube]

In another project, I'm also getting extra leading whitespace with fantomas 2.9.0:

[<Test>]
let ``should not confuse me with extra spaces v1``() =
    let codeSnippet = """let errorHandler = ProcessExiter(colorizer = function ErrorCode.HelpText -> None | _ -> Some ConsoleColor.Red)"""
    formatSourceString false codeSnippet config
    |> should equal """let errorHandler =
    ProcessExiter(colorizer = function
                  | ErrorCode.HelpText -> None
                  | _ -> Some ConsoleColor.Red)
"""