From 1b8b6f033014e7c4228ba45b9cef990c0cadc3ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Malte=20B=C3=BCnz?= <maltebuenz@posteo.de>
Date: Tue, 5 Mar 2024 15:23:14 +0100
Subject: [PATCH] Return `elements` for `ContentState.loading` to prevent
 blinking (#501)

---
 .../Sources/Helpers/ContentState.swift        |  2 +-
 .../ChatFeatureCoreTests.swift                | 35 +++++++++++++++++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/CriticalMapsKit/Sources/Helpers/ContentState.swift b/CriticalMapsKit/Sources/Helpers/ContentState.swift
index 36f4fd13b..0ff79d754 100644
--- a/CriticalMapsKit/Sources/Helpers/ContentState.swift
+++ b/CriticalMapsKit/Sources/Helpers/ContentState.swift
@@ -10,7 +10,7 @@ public enum ContentState<T: Hashable>: Equatable {
 
   public var elements: T? {
     switch self {
-    case let .results(results):
+    case let .results(results), let .loading(results):
       return results
     default:
       return nil
diff --git a/CriticalMapsKit/Tests/ChatFeatureTests/ChatFeatureCoreTests.swift b/CriticalMapsKit/Tests/ChatFeatureTests/ChatFeatureCoreTests.swift
index b5186ad5c..bb00c794b 100644
--- a/CriticalMapsKit/Tests/ChatFeatureTests/ChatFeatureCoreTests.swift
+++ b/CriticalMapsKit/Tests/ChatFeatureTests/ChatFeatureCoreTests.swift
@@ -1,6 +1,7 @@
 import ApiClient
 import ChatFeature
 import ComposableArchitecture
+import Helpers
 import L10n
 import SharedModels
 import UserDefaultsClient
@@ -11,10 +12,12 @@ final class ChatFeatureCore: XCTestCase {
   let uuid = { UUID(uuidString: "00000000-0000-0000-0000-000000000000")! }
   let date = { Date(timeIntervalSinceReferenceDate: 0) }
   
-  func defaultTestStore() -> TestStore<ChatFeature.State, ChatFeature.Action, ChatFeature.State, ChatFeature.Action, ()> {
+  func defaultTestStore(
+    with state: ContentState<[ChatMessage]> = .results([])
+  ) -> TestStore<ChatFeature.State, ChatFeature.Action, ChatFeature.State, ChatFeature.Action, ()> {
     let testStore = TestStore(
       initialState: ChatFeature.State(
-        chatMessages: .results([]),
+        chatMessages: state,
         chatInputState: .init(
           isEditing: true,
           message: "Hello World!"
@@ -49,6 +52,34 @@ final class ChatFeatureCore: XCTestCase {
     }
   }
   
+  func test_storeWithItems_shouldTriggerNetworkCall_withSuccessResponse_andHaveElements() async {
+    let testStore = defaultTestStore(
+      with: .loading([
+        ChatMessage(
+            identifier: "ID88878",
+            device: "Device",
+            message: "Hello World!",
+            timestamp: 1889.1
+          )
+      ])
+    )
+    testStore.dependencies.apiService.postChatMessage = { _ in return ApiResponse(status: "ok") }
+    testStore.dependencies.apiService.getChatMessages = { mockResponse }
+    
+    _ = await testStore.send(.chatInput(.onCommit)) { state in
+      state.chatInputState.isSending = true
+    }
+    await testStore.receive(.chatInputResponse(.success(.init(status: "ok")))) { state in
+      state.chatInputState.isSending = false
+      state.chatInputState.message = ""
+    }
+    await testStore.receive(.fetchChatMessages)
+    XCTAssertFalse(testStore.state.chatMessages.elements!.isEmpty)
+    await testStore.receive(.fetchChatMessagesResponse(.success(mockResponse))) {
+      $0.chatMessages = .results(mockResponse)
+    }
+  }
+  
   func test_chatInputAction_onCommit_shouldTriggerNetworkCallWithFailureResponse() async {
     let error = NSError(domain: "", code: 1)
     let testStore = defaultTestStore()