fsprojects
ExperimentalKeepIndentInBranch should fire when first branch was all on one line
Issue created from fantomas-online
Code
module Program =
let main _ =
if false then 1 else
printfn "hi!"
0
Result
module Program =
let main _ =
if false then
1
else
printfn "hi!"
0
Desired result
module Program =
let main _ =
if false then
1
else
printfn "hi!"
0
Problem description
This is a completely new request which we've never asked you for before, not a bug. (In general the ExperimentalKeepIndentInBranch feature works great nowadays, and I now instinctively expect it to do the right thing!)
If ExperimentalKeepIndentInBranch, it would be great if we could retain the indentation when there's a one-line "deal with some particular case" that we've reformatted onto multiple lines. I think this new pattern should only fire if the format is like this:
if blah then baz else
more stuff at the same level of indentation as the initial `if`
That is, the following reformatting shouldn't take place:
if blah then baz else foo
//
if blah then
baz
else
foo // note the lack of indent, which here would be incorrect
Rationale: if I've "clearly been trying" to keep the main body of my else block unindented, by explicitly putting it at the same level of indentation as the if keyword, then I think we shouldn't break that attempt merely because we reformatted the body of the if branch.
The actual code in the wild which triggered me to write this report is:
async {
if not (proc.Start ()) then return Error "failed to start" else
use stdout = proc.StandardOutput
let! ct = Async.CancellationToken
...
}
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.
- [ ] I would like a release if this problem is solved.
Options
Fantomas main branch at 2023-10-30T10:39:28Z - 3f293e712175343c2bcab1dfabe35cbb52fe8839
{ config with
ExperimentalKeepIndentInBranch = true }
Did you know that you can ignore files when formatting by using a .fantomasignore file? PS: It's unlikely that someone else will solve your specific issue, as it's something that you have a personal stake in.
Hi Patrick,
I've encountered this myself as well. I see your point.
The additional trigger should be the elseBranch matching the indentation of the if keyword right?
I'll take a look at this.
I released a new preview version with this: https://www.nuget.org/packages/fantomas/6.3.0-alpha-001
