Ionide-vscode-fsharp: Format document - array formatting bug

[stilettk]

Before:
```F#
module Input
let modules = [109024;137172;80445;80044]

**After:**
```F#
module Input

let modules = [ 109024; 137172; 80445; 80044 ]
]

Expected behaviour
F# module Input let modules = [ 109024; 137172; 80445; 80044 ]
To Reproduce
Steps to reproduce the behaviour:

1. Create file with "before" contents
2. Press Shift+Alt+F (Format document)

Environment (please complete the following information):

• OS: Widows 10 Pro 18363.476
• Ionide version: 4.3.2
• VSCode version: 1.40.2
• dotnet SDK version: 3.1.100
• mono / .Net Framework version: netcoreapp3.1

Additional context
Add any other context about the problem here.

[open-collective-bot[bot]]

Hey @stilettk :wave:,

Thank you for opening an issue. We will get back to you as
soon as we can. Also, check out our OpenCollective and consider
backing us.

https://opencollective.com/ionide

PS.: We offer backer support for all backers. Don't forget to add backer label when you start backing us :smile:

[baronfel]

Please open formatting bugs at the fantomas repository, https://github.com/fsprojects/fantomas. We consume them as a library to do all formatting.

[stilettk]

This is not reproduced in fantomas: link to online formatter
Maybe ionide doesn't use the latest version?

[baronfel]

You're exactly right. FSAC has been updated with the latest version already, so we need to do an update here of FSAC and this will be addressed. Thanks for reporting!

[Krzysztof-Cieslak]

Should be fixed in 4.4.x

[stilettk]

@Krzysztof-Cieslak Unfortunately, I can still reproduce it in ionide 4.4.2...

[baronfel]

@Krzysztof-Cieslak we should reopen this, the problem seems to be on our side in FSAC.

Given fsx script of:

module Input
    let modules = [109024;137172;80445;80044]

the result of the formatting call is

[Trace - 3:22:08 PM] Sending request 'textDocument/formatting - (62)'.
Params: {
    "textDocument": {
        "uri": "file:///Users/chethusk/oss/CppSharp/build/gmake/lib/Release_x64/gen/scratch.fsx"
    },
    "options": {
        "tabSize": 4,
        "insertSpaces": true
    }
}


[Trace - 3:22:08 PM] Received response 'textDocument/formatting - (62)' in 7ms.
Result: [
    {
        "range": {
            "start": {
                "line": 0,
                "character": 0
            },
            "end": {
                "line": 1,
                "character": 44
            }
        },
        "newText": "module Input\n\nlet modules = [ 109024; 137172; 80445; 80044 ]\n"
    }
]

The key thing is the response has a range of (0,0)-(1,44) (relative to the initial text), and the response text is "module Input\n\nlet modules = [ 109024; 137172; 80445; 80044 ]\n", which is what we expect in this case. I think there's something wrong with the range calculation (because line 2 of the input text (aka line 1 from FSC range perspective) has 45 characters, not 44. I think we're replacing everything from (0,0)-(1,44) with the newText (which ends in newline) and the the last character of ] is being appended.

[Krzysztof-Cieslak]

@baronfel fixed that on FSAC side, fix will be available in next Ionide release