Add unit tests

Tests/DataLiteCoreTests/Protocols/ArgumentsProtocolTests.swift

@@ -0,0 +1,46 @@
+import Foundation
+import Testing
+import DataLiteCore
+
+struct ArgumentsProtocolTests {
+    @Test func typedSubscript() {
+        let arguments: Arguments = [
+            .text("one"),
+            .text("two"),
+            .int(42)
+        ]
+
+        #expect(arguments[0] == TestModel.one)
+        #expect(arguments[1] == TestModel.two)
+        #expect(arguments[2] as TestModel? == nil)
+    }
+}
+
+private extension ArgumentsProtocolTests {
+    enum TestModel: String, SQLiteRepresentable {
+        case one, two
+    }
+    
+    struct Arguments: ArgumentsProtocol, ExpressibleByArrayLiteral {
+        private let values: [SQLiteValue]
+        
+        var startIndex: Int { values.startIndex }
+        var endIndex: Int { values.endIndex }
+        
+        init(_ values: [SQLiteValue]) {
+            self.values = values
+        }
+        
+        init(arrayLiteral elements: SQLiteValue...) {
+            self.values = elements
+        }
+        
+        subscript(index: Int) -> SQLiteValue {
+            values[index]
+        }
+        
+        func index(after i: Int) -> Int {
+            values.index(after: i)
+        }
+    }
+}