Refactoring userVersion + adding tests

Author: nathanfallet

Sources/SQLite/Core/Connection.swift

@@ -151,12 +151,22 @@ public final class Connection {
     public var totalChanges: Int {
         Int(sqlite3_total_changes(handle))
     }
-    
-    /// The user version of the database.
+
+    /// Gets the user version of the database.
+    /// See SQLite [PRAGMA user_version](https://sqlite.org/pragma.html#pragma_user_version)
+    /// - Returns: the user version of the database
+    public func getUserVersion() throws -> Int32? {
+        guard let userVersion = try scalar("PRAGMA user_version") as? Int64 else {
+            return nil
+        }
+        return Int32(userVersion)
+    }
+
+    /// Sets the user version of the database.
     /// See SQLite [PRAGMA user_version](https://sqlite.org/pragma.html#pragma_user_version)
-    public var userVersion: Int32 {
-        get { return Int32(try! scalar("PRAGMA user_version") as! Int64)}
-        set { try! run("PRAGMA user_version = \(newValue)") }
+    /// - Parameter userVersion: the new user version of the database
+    public func setUserVersion(to userVersion: Int32) throws {
+        try run("PRAGMA user_version = \(userVersion)")
     }
 
     // MARK: - Execute

Tests/SQLiteTests/ConnectionTests.swift

@@ -96,6 +96,11 @@ class ConnectionTests: SQLiteTestCase {
         XCTAssertEqual(2, db.totalChanges)
     }
 
+    func test_userVersion() {
+        try! db.setUserVersion(to: 2)
+        XCTAssertEqual(2, try! db.getUserVersion()!)
+    }
+
     func test_prepare_preparesAndReturnsStatements() {
         _ = try! db.prepare("SELECT * FROM users WHERE admin = 0")
         _ = try! db.prepare("SELECT * FROM users WHERE admin = ?", 0)