else if handling misplaces directive located between the keywords

[majocha]

Issue created from fantomas-online

Code

if true then 0
else
#if FOO
    if false then 1
    else
#endif
        2

Result

if true then
    0
else if
#if FOO

    false
then
    1
else
#endif
    2

Problem description

Directive before if moves after it, changing semantics and/or making the code invalid.

Extra information

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

It came on my mind to test this while trying to tackle #2752. I'm not sure if this one will also make a good first issue :)

Options

Fantomas main branch at 2023-02-04T13:46:10Z - 9f769d8

    { config with
                KeepMaxNumberOfBlankLines = 1 }

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

[nojaf]

Hello, thank you for reporting this issue.

The input here is quite the departure from what the style guide recommends, and that can lead to the bug you see here.

If the code follows the guide better, for example, it is able to correctly format it. This might be the workaround you can use in your production code.

I'm afraid I can't really point you in any direction for this one. From a technical standpoint, there is no relation between the #if FOO and #endif so I don't really know what can be done about this.

[majocha]

Hi, @nojaf.
Thanks for the swift and detailed response.
This is a contrived example I did, so I probably shouldn't tick "breaks my code" when what I had on mind is "it could break code".

Now is I look at it I notice this should probably be caught by isValidFSharpCode because with the define unset it becomes:

if true then
    0
else if
    2