[WIP] Add basic support for "Consistent" Pattern Matching

[isaacabraham]

Just an initial WIP PR.

[nojaf]

I would prefer a boolean setting for this. This would be much more consistent with most other Fantomas settings.

Some reasons:

• Typo's are less likely in editorconfig.
• Online tool doesn't need to be update.
• There are only two values here, most other DU's have three.

[isaacabraham]

Yes, I had thought about that. The reason I put it as an enum was because the original feature request had 4 cases (these two, plus "always single" and "always multiline"). Happy to move to a bool, although it would be a little less readable i.e. instead of mode, it would be e.g. ConsistentPatternMatching = true / false with the false case being "implicitly" the standard / existing behaviour.

[isaacabraham]

Nonetheless, it would be helpful to know why the current unit test is broken - any ideas?

[nojaf]

I appreciate your enthusiasm, but at the moment, we don't have enough support to justify having four different cases for this. Right now, we're considering just a boolean setting as an alternative approach. The other options aren't really worth pursuing at this stage.

it would be helpful to know why the current unit test is broken - any ideas?

To give you a better answer, I'd need to see the test running on CI. My initial guess is that there might be an issue with your DU.

Thanks for understanding!

[isaacabraham]

Not really enthusiasm - just was thinking of the right thing to do. I've no problem to convert to a boolean and will do.

I've fixed the formatting so that should get the CI working anyway so that we can see the test fail on CI (hopefully) - that might enable you to explain why the test is failing, which would be good to know in order to improve my understanding of the Fantomas codebase, enabling me to become a more active participant in the future!

[nojaf]

I noticed you did not update

fantomas/src/Fantomas/Daemon.fs

Lines 125 to 173 in 873d9d7

	[<JsonRpcMethod(Methods.Configuration)>]
	member _.Configuration() : string =
	let settings =
	Reflection.getRecordFields FormatConfig.Default
	|> Array.toList
	|> List.choose (fun (recordField, defaultValue) ->
	let optionalField key value =
	value |> Option.toList |> List.map (fun v -> key, Encode.string v)
	let meta =
	List.concat
	[| optionalField "category" recordField.Category
	optionalField "displayName" recordField.DisplayName
	optionalField "description" recordField.Description |]
	let type' =
	match defaultValue with
	| :? bool as b ->
	Some(
	Encode.object
	[ yield "type", Encode.string "boolean"
	yield "defaultValue", Encode.string (if b then "true" else "false")
	yield! meta ]
	)
	| :? int as i ->
	Some(
	Encode.object
	[ yield "type", Encode.string "number"
	yield "defaultValue", Encode.string (string<int> i)
	yield! meta ]
	)
	| :? MultilineFormatterType as m ->
	Some(
	Encode.object
	[ yield "type", Encode.string "multilineFormatterType"
	yield "defaultValue", Encode.string (MultilineFormatterType.ToConfigString m)
	yield! meta ]
	)
	| :? EndOfLineStyle as e ->
	Some(
	Encode.object
	[ yield "type", Encode.string "endOfLineStyle"
	yield "defaultValue", Encode.string (EndOfLineStyle.ToConfigString e)
	yield! meta ]
	)
	| _ -> None
	type' |> Option.map (fun t -> toEditorConfigName recordField.PropertyName, t))
	|> Encode.object

with your new config thing.

The build errors I noticed on the CI, are likely a result of 8.0.300 being installed on the agent.

[isaacabraham]

Great, thanks for this - that's the bit I couldn't find.