Clear out trace

Author: jberkel

Tests/SQLiteTests/ConnectionTests.swift

@@ -157,7 +157,7 @@ class ConnectionTests : SQLiteTestCase {
 
     func test_transaction_rollsBackTransactionsIfCommitsFail() {
         // This test case needs to emulate an environment where the individual statements succeed, but committing the
-        // transactuin fails. Using deferred foreign keys is one option to achieve this.
+        // transaction fails. Using deferred foreign keys is one option to achieve this.
         try! db.execute("PRAGMA foreign_keys = ON;")
         try! db.execute("PRAGMA defer_foreign_keys = ON;")
         let stmt = try! db.prepare("INSERT INTO users (email, manager_id) VALUES (?, ?)", "alice@example.com", 100)

Tests/SQLiteTests/TestHelpers.swift

@@ -2,15 +2,13 @@ import XCTest
 @testable import SQLite
 
 class SQLiteTestCase : XCTestCase {
-
-    var trace = [String: Int]()
-
-    let db = try! Connection()
-
+    private var trace:[String: Int]!
     let users = Table("users")
+    let db = try! Connection()
 
     override func setUp() {
         super.setUp()
+        trace = [String:Int]()
 
         db.trace { SQL in
             print(SQL)