“FS0058: Possible incorrect indentation” around if/then/else after running Fantomas

[lydell]

Issue created from fantomas-online

Code

// Original input:
let x =
    if not (f aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) then
        1
    else
        2

// Formatted output of the above, in for a second format:
let x =
    if (not (
            f aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
        )) then
        1
    else
        2

Result

// Original input:
let x =
    if (not (
            f aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
        )) then
        1
    else
        2

// Formatted output of the above, in for a second format:
let x =
    if (not (
        f aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    )) then
        1
    else
        2

Problem description

Formatting the input results in:

FS0058: Possible incorrect indentation, this token is offside of context ...

The issue is not only the compiler warning, but also:

• Idempotency. Running Fantomas twice causes further changes.
• Redundant parens around the if condition?

Workaround: Extract the condition into a let.

Extracted from #1342

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 01/05/2021 21:00:18 - d5f4d9f

Default Fantomas configuration

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

[nojaf]

Hey @lydell, I believe I can solve the idempotency problem.
As for why the parenthesises are introduced, see linked compiler issue.