Add unit tests

Sources/DataLiteCore/Protocols/ConnectionDelegate.swift

@@ -2,11 +2,9 @@ import Foundation
 
 /// A delegate that observes connection-level database events.
 ///
-/// Conforming types can monitor row-level updates and transaction lifecycle events. All methods are
-/// optional — default implementations do nothing.
-///
-/// This protocol is typically used for debugging, logging, or synchronizing application state with
-/// database changes.
+/// Conforming types can monitor row-level updates and transaction lifecycle events. This protocol
+/// is typically used for debugging, logging, or synchronizing application state with database
+/// changes.
 ///
 /// - Important: Delegate methods are invoked synchronously on SQLite’s internal execution thread.
 ///   Implementations must be lightweight and non-blocking to avoid slowing down SQL operations.
@@ -43,9 +41,3 @@ public protocol ConnectionDelegate: AnyObject {
     /// - Parameter connection: The connection that rolled back.
     func connectionDidRollback(_ connection: ConnectionProtocol)
 }
-
-public extension ConnectionDelegate {
-    func connection(_ connection: ConnectionProtocol, didUpdate action: SQLiteAction) {}
-    func connectionWillCommit(_ connection: ConnectionProtocol) throws {}
-    func connectionDidRollback(_ connection: ConnectionProtocol) {}
-}

Sources/DataLiteCore/Protocols/ConnectionProtocol.swift

@@ -12,10 +12,10 @@ import Foundation
 ///
 /// - ``isAutocommit``
 /// - ``isReadonly``
-/// - ``busyTimeout``
 ///
 /// ### Accessing PRAGMA Values
 ///
+/// - ``busyTimeout``
 /// - ``applicationID``
 /// - ``foreignKeys``
 /// - ``journalMode``
@@ -84,6 +84,8 @@ public protocol ConnectionProtocol: AnyObject {
     /// - SeeAlso: [Determine if a database is read-only](https://sqlite.org/c3ref/db_readonly.html)
     var isReadonly: Bool { get }
     
+    // MARK: - PRAGMA Accessors
+    
     /// The busy timeout of the connection, in milliseconds.
     ///
     /// Defines how long SQLite waits for a locked database to become available before returning
@@ -93,8 +95,6 @@ public protocol ConnectionProtocol: AnyObject {
     /// - SeeAlso: [Set A Busy Timeout](https://sqlite.org/c3ref/busy_timeout.html)
     var busyTimeout: Int32 { get set }
     
-    // MARK: - PRAGMA Accessors
-    
     /// The application identifier stored in the database header.
     ///
     /// Used to distinguish database files created by different applications or file formats. This

Sources/DataLiteCore/Protocols/StatementProtocol.swift

@@ -8,6 +8,11 @@ import Foundation
 ///
 /// ## Topics
 ///
+/// ### Retrieving Statement SQL
+///
+/// - ``sql``
+/// - ``expandedSQL``
+///
 /// ### Binding Parameters
 ///
 /// - ``parameterCount()``
@@ -34,6 +39,20 @@ import Foundation
 /// - ``columnValue(at:)->T?``
 /// - ``currentRow()``
 public protocol StatementProtocol {
+    // MARK: - Retrieving Statement SQL
+    
+    /// The original SQL text used to create this prepared statement.
+    ///
+    /// Returns the statement text as it was supplied when the statement was prepared. Useful for
+    /// diagnostics or query introspection.
+    var sql: String? { get }
+    
+    /// The SQL text with all parameter values expanded into their literal forms.
+    ///
+    /// Shows the actual SQL string that would be executed after parameter binding. Useful for
+    /// debugging and logging queries.
+    var expandedSQL: String? { get }
+    
     // MARK: - Binding Parameters
     
     /// Returns the number of parameters in the prepared SQLite statement.
@@ -101,7 +120,7 @@ public protocol StatementProtocol {
     ///
     /// - Parameters:
     ///   - value: The ``SQLiteValue`` to bind.
-    ///   - name: The parameter name as written in SQL, including its prefix.
+    ///   - name: The parameter name exactly as written in SQL, including its prefix.
     /// - Throws: ``SQLiteError`` if binding fails.
     ///
     /// - SeeAlso: [Binding Values To Prepared Statements](
@@ -130,7 +149,7 @@ public protocol StatementProtocol {
     ///
     /// - Parameters:
     ///   - value: The value to bind. If `nil`, `NULL` is bound.
-    ///   - name: The parameter name as written in SQL, including its prefix.
+    ///   - name: The parameter name exactly as written in SQL, including its prefix.
     /// - Throws: ``SQLiteError`` if binding fails.
     ///
     /// - SeeAlso: [Binding Values To Prepared Statements](