Add ndb subscription tests

Signed-off-by: Daniel D’Aquino <daniel@daquino.me>

damusTests/NostrNetworkManagerTests/NostrNetworkManagerTests.swift

@@ -0,0 +1,86 @@
+//
+//  NostrNetworkManagerTests.swift
+//  damus
+//
+//  Created by Daniel D'Aquino on 2025-08-22.
+//
+
+import XCTest
+@testable import damus
+
+
+class NostrNetworkManagerTests: XCTestCase {
+    var damusState: DamusState? = nil
+    
+    override func setUpWithError() throws {
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+        damusState = generate_test_damus_state(mock_profile_info: nil)
+
+        let notesJSONL = getTestNotesJSONL()
+
+        for noteText in notesJSONL.split(separator: "\n") {
+            let _ = damusState!.ndb.process_event("[\"EVENT\",\"subid\",\(String(noteText))]")
+        }
+    }
+    
+    override func tearDownWithError() throws {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+        damusState = nil
+    }
+    
+    func getTestNotesJSONL() -> String {
+        // Get the path for the test_notes.jsonl file in the same folder as this test file
+        let testBundle = Bundle(for: type(of: self))
+        let fileURL = testBundle.url(forResource: "test_notes", withExtension: "jsonl")!
+
+        // Load the contents of the file
+        return try! String(contentsOf: fileURL, encoding: .utf8)
+    }
+    
+    func ensureSubscribeGetsAllExpectedNotes(filter: NostrFilter, expectedCount: Int) {
+        let endOfStream = XCTestExpectation(description: "Stream should receive EOSE")
+        let gotAtLeastExpectedCount = XCTestExpectation(description: "Stream should receive at least the expected number of items")
+        var receivedCount = 0
+        var eventIds: Set<NoteId> = []
+        Task {
+            for await item in self.damusState!.nostrNetwork.reader.subscribe(filters: [filter]) {
+                switch item {
+                case .event(borrow: let borrow):
+                    try? borrow { event in
+                        receivedCount += 1
+                        if eventIds.contains(event.id) {
+                            XCTFail("Got duplicate event ID: \(event.id) ")
+                        }
+                        eventIds.insert(event.id)
+                    }
+                    if receivedCount == expectedCount {
+                        gotAtLeastExpectedCount.fulfill()
+                    }
+                case .eose:
+                    // End of stream, break out of the loop
+                    endOfStream.fulfill()
+                }
+            }
+        }
+        wait(for: [endOfStream, gotAtLeastExpectedCount], timeout: 10.0)
+        XCTAssertEqual(receivedCount, expectedCount, "Event IDs: \(eventIds.map({ $0.hex() }))")
+    }
+    
+    /// Tests to ensure that subscribing gets the correct amount of events
+    ///
+    /// ## Implementation notes:
+    ///
+    /// To create a new scenario, `nak` can be used as a reference:
+    /// 1. `cd` into the folder where the `test_notes.jsonl` file is
+    /// 2. Run `nak serve --events test_notes.jsonl`
+    /// 3. On a separate terminal, run `nak` commands with the desired filter against the local relay, and get the line count. Example:
+    /// ```
+    /// nak req --kind 1 ws://localhost:10547 | wc -l
+    /// ```
+    func testNdbSubscription() {
+        ensureSubscribeGetsAllExpectedNotes(filter: NostrFilter(kinds: [.text]), expectedCount: 57)
+        ensureSubscribeGetsAllExpectedNotes(filter: NostrFilter(authors: [Pubkey(hex: "32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245")!]), expectedCount: 22)
+        ensureSubscribeGetsAllExpectedNotes(filter: NostrFilter(kinds: [.boost], referenced_ids: [NoteId(hex: "64b26d0a587f5f894470e1e4783756b4d8ba971226de975ee30ac1b69970d5a1")!]), expectedCount: 5)
+        ensureSubscribeGetsAllExpectedNotes(filter: NostrFilter(kinds: [.text, .boost, .zap], referenced_ids: [NoteId(hex: "64b26d0a587f5f894470e1e4783756b4d8ba971226de975ee30ac1b69970d5a1")!], limit: 500), expectedCount: 5)
+    }
+}