Stub onion request path building test

SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI.swift

@@ -1,8 +1,8 @@
 import PromiseKit
 
 internal enum OnionRequestAPI {
-    private static let workQueue = DispatchQueue.global() // TODO: We should probably move away from using the global queue for this
-
+    /// - Note: Exposed for testing purposes.
+    internal static let workQueue = DispatchQueue.global() // TODO: We should probably move away from using the global queue for this
     internal static var guardSnodes: Set<LokiAPITarget> = []
     internal static var paths: Set<Path> = []
 

SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPITests.swift

@@ -2,5 +2,19 @@
 import XCTest
 
 class OnionRequestAPITests : XCTestCase {
+    private let maxRetryCount: UInt = 2 // Be a bit more stringent when testing
 
+    // TODO: Remove dependency on SSKEnvironment
+
+    func testGetPath() {
+        let semaphore = DispatchSemaphore(value: 0)
+        var error: Error? = nil
+        let _ = OnionRequestAPI.getPath().retryingIfNeeded(maxRetryCount: maxRetryCount).done(on: OnionRequestAPI.workQueue) { _ in
+            semaphore.signal()
+        }.catch(on: OnionRequestAPI.workQueue) {
+            error = $0; semaphore.signal()
+        }
+        semaphore.wait()
+        XCTAssert(error == nil)
+    }
 }