[SR-14703] Code completion returns no result for key path with generic base

[ahoppen]

Previous ID	SR-14703
Radar	rdar://78779335
Original Reporter	@ahoppen
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	CodeCompletion
Labels	Bug, FoundByStressTester
Assignee	@ahoppen
Priority	Medium

md5: cbe8aa5a44b2397d188ffcc680fc92cc

relates to:

• SR-14685 Code completion returns no results for key path with generic return type

Issue Description:

In the following test case, villager is not suggested, even though its generic base could be fully inferred.

// RUN: %swift-ide-test --code-completion --source-filename %s --code-completion-token=COMPLETE -I %S/Inputs/Purchases.swiftinterface

struct Villager {}

struct AnyPublisher2 {
  func assign<Root>(to keyPath: ReferenceWritableKeyPath<Root, Villager>, on object: Root) { fatalError() }
}

class VillagersViewModel {
  var villager: Villager = Villager()

  private func fetch(apiPublisher: AnyPublisher2) {
    apiPublisher.assign(to: \.#^COMPLETE^#villager, on: self)
  }
}

[ahoppen]

Fixed in #38049