Incorrect indentation after interface member with anonymous record as generic type

[theimowski]

Issue created from fantomas-online

Code

// ts2fable 0.8.0
module rec Xterm

type [<AllowNullLiteral>] Terminal =
    abstract onKey: IEvent<{| key: string; domEvent: KeyboardEvent |}> with get, set
    abstract onLineFeed: IEvent<unit> with get, set

Result

// ts2fable 0.8.0
module rec Xterm

[<AllowNullLiteral>]
type Terminal =
    abstract onKey:
        IEvent<{| key: string
                  domEvent: KeyboardEvent |}> with get, set

abstract onLineFeed: IEvent<unit> with get, set

• following error:

(10,0) (10, 8)Error
Unexpected keyword 'abstract' in definition. Expected incomplete structured construct at or before this point or other token.

Problem description

Generated Fable bindings for https://xtermjs.org/ using https://fable.io/ts2fable/ and Fantomas generates invalid F# code when formatting the bindings

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.

Options

Fantomas master branch at 2022-08-01T12:33:32Z - e2eda79

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]

Siema!

I believe this issue can be resolved by changing 0 to 1 in:

fantomas/src/Fantomas.Core/CodePrinter.fs

Line 4031 in 3706d26

if lastIndex < 0 then

This will avoid the additional unindent.

Are you interested in submitting a PR for this?

[theimowski]

Siema :)

Sounds like a serious change - challenge accepted! (will take the credits)

I'll see if I can submit a PR with a test tomorrow 🤞

[nojaf]

Thanks, you can add the test to ClassTests.
Please checkout the guidelines as well.
Good luck!