Problem parsing generic function parameters when function split over multiple lines

[mwoollard]

When documenting the following definition the following is parsed fine:

public protocol VehiclePositionManager {
    func positions(for region: Observable<LocationRegion?>, stopId: String?, routeIds: [String]?) -> Observable<[VehiclePositionType]>
    
}

But if the function is broken over several lines it gets truncated in the docs:

public protocol VehiclePositionManager {
    func positions(for region: Observable<LocationRegion?>,
                   stopId: String?, 
                   routeIds: [String]?) -> Observable<[VehiclePositionType]>
}

This problem doesn't appear to happen if the function parameters don't include any generic definitions.

Thanks
Mark

[johnfairh]

I think this happens for all multi-line function declarations inside protocols, the generic types look like a coincidence.

[johnfairh]

This turns out to be tough to completely fix. SourceKitten normally uses the 'body offset' key to know when the declaration ends, which is absent for protocol methods. A rule like for functions without 'body offset', use 'length' works correctly in the example here, but it turns out 'length' does not include any where clause meaning that always gets dropped, even if all on one line. Not sure if that is an improvement.

With PR #902 as-is, these function definitions show up entirely but all on one long line, which is correct but ugly. Could add a ghastly rule there, assuming the sourcekitten change [ie. respect multi-line but always drop where clause], to say "if protocol func has multiple lines then use the multi-line version, unless it also has generic parameter constraints in which case use the all-on-one-line version".

[johnfairh]

I fixed the underlying Swift problem with where so this issue should be fixable for real in 4.2/5.0 with a SourceKitten tweak.

[johnfairh]

Jazzy has a workaround for this now, prints the function on a single line. Trying to do the 'real' fix found another Swift bug causing a separate regression: will have to wait another cycle.

[mwoollard]

OK thanks for the update

[johnfairh]

Fixed in master (with a Swift 5.1+ project)