| 1 | import XCTest |
| 2 | @testable import LChatCore |
| 3 | |
| 4 | // 🤖 Regression guard for issue #580 (iOS threading). A stalled main thread let |
| 5 | // a member's repeated taps on a chat row queue; each ran the list's |
| 6 | // `path.append(.thread(id))`, so the NavigationStack ended up holding duplicate |
| 7 | // copies of one chat and "back" surfaced a phantom second copy. The push must |
| 8 | // be idempotent while that chat is already on top. |
| 9 | // |
| 10 | // This can't reproduce the underlying STALL (that lives in the SwiftUI layout |
| 11 | // engine / gesture system), but it pins the state-machine invariant the stall |
| 12 | // exposed: N taps on the same chat → exactly one push. |
| 13 | final class ChatNavGuardTests: XCTestCase { |
| 14 | |
| 15 | // Model the list's onSelect reducer over a stack of pushed thread ids |
| 16 | // (empty = the chat list on top). Mirrors ThreadListView's push. |
| 17 | private func applyTaps(_ taps: [String], guarded: Bool) -> [String] { |
| 18 | var stack: [String] = [] |
| 19 | for id in taps { |
| 20 | if !guarded || ChatNavGuard.shouldPush(threadID: id, topThreadID: stack.last) { |
| 21 | stack.append(id) |
| 22 | } |
| 23 | } |
| 24 | return stack |
| 25 | } |
| 26 | |
| 27 | // The bug, reproduced: four queued taps on ONE chat push four copies when |
| 28 | // unguarded — exactly the "back went to a second copy" report. |
| 29 | func testQueuedTapsDuplicateWithoutGuard() { |
| 30 | XCTAssertEqual(applyTaps(["T1", "T1", "T1", "T1"], guarded: false), |
| 31 | ["T1", "T1", "T1", "T1"]) |
| 32 | } |
| 33 | |
| 34 | // The fix: the same queued taps collapse to a single push. |
| 35 | func testQueuedTapsCollapseWithGuard() { |
| 36 | XCTAssertEqual(applyTaps(["T1", "T1", "T1", "T1"], guarded: true), ["T1"]) |
| 37 | } |
| 38 | |
| 39 | // Guarding must not block legitimate navigation between DIFFERENT chats. |
| 40 | func testDistinctChatsStillPush() { |
| 41 | XCTAssertEqual(applyTaps(["T1", "T2", "T3"], guarded: true), ["T1", "T2", "T3"]) |
| 42 | } |
| 43 | |
| 44 | // Re-opening a chat you just left is legitimate — it isn't on top anymore. |
| 45 | func testReopenAfterLeavingPushes() { |
| 46 | var stack = ["T1"] |
| 47 | stack.removeLast() // back to the list |
| 48 | if ChatNavGuard.shouldPush(threadID: "T1", topThreadID: stack.last) { |
| 49 | stack.append("T1") |
| 50 | } |
| 51 | XCTAssertEqual(stack, ["T1"]) |
| 52 | } |
| 53 | |
| 54 | func testShouldPushPredicate() { |
| 55 | XCTAssertTrue(ChatNavGuard.shouldPush(threadID: "T1", topThreadID: nil)) // from the list |
| 56 | XCTAssertTrue(ChatNavGuard.shouldPush(threadID: "T2", topThreadID: "T1")) // switching chats |
| 57 | XCTAssertFalse(ChatNavGuard.shouldPush(threadID: "T1", topThreadID: "T1")) // already on top |
| 58 | } |
| 59 | } |
| 60 | |
amadan