From 62611be006a18322501c2da64d0fc75be50d2d07 Mon Sep 17 00:00:00 2001
From: Doug <6060466+pixlwave@users.noreply.github.com>
Date: Mon, 27 Jan 2025 11:44:21 +0000
Subject: [PATCH] Show a blank topic as removed. (#3706)

---
 .../RoomStateEventStringBuilder.swift         | 10 ++++-----
 .../RoomStateEventStringBuilderTests.swift    | 22 +++++++++++++++++++
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/ElementX/Sources/Services/Timeline/TimelineItems/RoomStateEventStringBuilder.swift b/ElementX/Sources/Services/Timeline/TimelineItems/RoomStateEventStringBuilder.swift
index 27a0f0cca..2d2fa3c7f 100644
--- a/ElementX/Sources/Services/Timeline/TimelineItems/RoomStateEventStringBuilder.swift
+++ b/ElementX/Sources/Services/Timeline/TimelineItems/RoomStateEventStringBuilder.swift
@@ -169,13 +169,13 @@ struct RoomStateEventStringBuilder {
             }
         case .roomTopic(let topic):
             switch (topic, isOutgoing) {
-            case (.some(let topic), false):
+            case (.some(let topic), false) where !topic.isBlank:
                 return L10n.stateEventRoomTopicChanged(displayName, topic)
-            case (nil, false):
+            case (_, false):
                 return L10n.stateEventRoomTopicRemoved(displayName)
-            case (.some(let name), true):
-                return L10n.stateEventRoomTopicChangedByYou(name)
-            case (nil, true):
+            case (.some(let topic), true) where !topic.isBlank:
+                return L10n.stateEventRoomTopicChangedByYou(topic)
+            case (_, true):
                 return L10n.stateEventRoomTopicRemovedByYou
             }
         case .roomPinnedEvents(let change):
diff --git a/UnitTests/Sources/RoomStateEventStringBuilderTests.swift b/UnitTests/Sources/RoomStateEventStringBuilderTests.swift
index 14dbcdf9a..0445bc89b 100644
--- a/UnitTests/Sources/RoomStateEventStringBuilderTests.swift
+++ b/UnitTests/Sources/RoomStateEventStringBuilderTests.swift
@@ -80,4 +80,26 @@ class RoomStateEventStringBuilderTests: XCTestCase {
                                                             memberIsYou: sender.id == userID)
         XCTAssertEqual(string, expectedString)
     }
+    
+    func testTopicChanges() {
+        let you = TimelineItemSender(id: userID, displayName: "Alice")
+        let other = TimelineItemSender(id: "@bob:matrix.org", displayName: "Bob")
+        
+        let newTopic = "New topic"
+        var string = stringBuilder.buildString(for: .roomTopic(topic: newTopic), sender: you, isOutgoing: true)
+        XCTAssertEqual(string, L10n.stateEventRoomTopicChangedByYou(newTopic))
+        string = stringBuilder.buildString(for: .roomTopic(topic: newTopic), sender: other, isOutgoing: false)
+        XCTAssertEqual(string, L10n.stateEventRoomTopicChanged(other.displayName ?? "", newTopic))
+        
+        let emptyTopic = ""
+        string = stringBuilder.buildString(for: .roomTopic(topic: emptyTopic), sender: you, isOutgoing: true)
+        XCTAssertEqual(string, L10n.stateEventRoomTopicRemovedByYou)
+        string = stringBuilder.buildString(for: .roomTopic(topic: emptyTopic), sender: other, isOutgoing: false)
+        XCTAssertEqual(string, L10n.stateEventRoomTopicRemoved(other.displayName ?? ""))
+        
+        string = stringBuilder.buildString(for: .roomTopic(topic: nil), sender: you, isOutgoing: true)
+        XCTAssertEqual(string, L10n.stateEventRoomTopicRemovedByYou)
+        string = stringBuilder.buildString(for: .roomTopic(topic: nil), sender: other, isOutgoing: false)
+        XCTAssertEqual(string, L10n.stateEventRoomTopicRemoved(other.displayName ?? ""))
+    }
 }