Change to new message format

Tests/AppTests/AppTests.swift

@@ -2,14 +2,44 @@
 import XCTVapor
 
 final class AppTests: XCTestCase {
-    func testHelloWorld() throws {
-        let app = Application(.testing)
-        defer { app.shutdown() }
-        try configure(app)
 
-        try app.test(.GET, "hello", afterResponse: { res in
-            XCTAssertEqual(res.status, .ok)
-            XCTAssertEqual(res.body.string, "Hello, world!")
-        })
+    func testEncodingUInt32() {
+        let input: UInt32 = 123
+        let data = input.encoded
+        let output = UInt32(data: data)
+        XCTAssertEqual(input, output)
+    }
+
+    func testEncodingContent() {
+        let input = Message.Content(time: 1234567890, id: 23456789)
+        let data = input.encoded
+        let output = Message.Content(decodeFrom: data)
+        XCTAssertEqual(input, output)
+        let data2 = Data([42, 42]) + data
+        let output2 = Message.Content(decodeFrom: Data(data2[2...]))
+        XCTAssertEqual(input, output2)
+    }
+
+    func testEncodingMessage() {
+        let input = Message(mac: Data(repeating: 42, count: 32),
+                            content: Message.Content(time: 1234567890, id: 23456789))
+        let data = input.encoded
+        let buffer = ByteBuffer(data: data)
+        let output = Message(decodeFrom: buffer)
+        XCTAssertEqual(input, output)
+    }
+
+    func testSigning() throws {
+        let key = SymmetricKey(size: .bits256)
+        let content = Message.Content(time: 1234567890, id: 23456789)
+        let input = content.authenticate(using: key)
+        XCTAssertTrue(input.isValid(using: key))
+
+        let data = content.authenticateAndSerialize(using: key)
+        let decoded = Message(decodeFrom: ByteBuffer(data: data))
+        XCTAssertNotNil(decoded)
+        XCTAssertTrue(decoded!.isValid(using: key))
+        XCTAssertEqual(decoded!, input)
+        XCTAssertEqual(content, input.content)
     }
 }