create labelsPublisher to fetch existing labels

apple/OmnivoreKit/Sources/App/Views/Profile/LabelsView.swift

@@ -11,18 +11,18 @@ final class LabelsViewModel: ObservableObject {
 
   var subscriptions = Set<AnyCancellable>()
 
-  func loadLabels(dataService _: DataService) {
+  func loadLabels(dataService: DataService) {
     isLoading = true
 
-//    dataService.newsletterEmailsPublisher().sink(
-//      receiveCompletion: { _ in },
-//      receiveValue: { [weak self] result in
-//        self?.isLoading = false
-//        self?.emails = result
-//        self?.hasLoadedInitialLabels = true
-//      }
-//    )
-//    .store(in: &subscriptions)
+    dataService.labelsPublisher().sink(
+      receiveCompletion: { _ in },
+      receiveValue: { [weak self] result in
+        self?.isLoading = false
+        self?.labels = result
+        self?.hasLoadedInitialLabels = true
+      }
+    )
+    .store(in: &subscriptions)
   }
 
   func createLabel(dataService _: DataService) {

apple/OmnivoreKit/Sources/Services/DataService/Queries/LabelsPublisher.swift

@@ -0,0 +1,49 @@
+import Combine
+import Foundation
+import Models
+import SwiftGraphQL
+
+public extension DataService {
+  func labelsPublisher() -> AnyPublisher<[FeedItemLabel], ServerError> {
+    enum QueryResult {
+      case success(result: [FeedItemLabel])
+      case error(error: String)
+    }
+
+    let selection = Selection<QueryResult, Unions.LabelsResult> {
+      try $0.on(labelsSuccess: .init {
+        QueryResult.success(result: try $0.labels(selection: feedItemLabelSelection.list))
+      },
+      labelsError: .init {
+        QueryResult.error(error: try $0.errorCodes().description)
+      })
+    }
+
+    let query = Selection.Query {
+      try $0.labels(selection: selection)
+    }
+
+    let path = appEnvironment.graphqlPath
+    let headers = networker.defaultHeaders
+
+    return Deferred {
+      Future { promise in
+        send(query, to: path, headers: headers) { result in
+          switch result {
+          case let .success(payload):
+            switch payload.data {
+            case let .success(result: result):
+              promise(.success(result))
+            case .error:
+              promise(.failure(.unknown))
+            }
+          case .failure:
+            promise(.failure(.unknown))
+          }
+        }
+      }
+    }
+    .receive(on: DispatchQueue.main)
+    .eraseToAnyPublisher()
+  }
+}