add comparator test

Package.swift

@@ -245,6 +245,10 @@ let package = Package(
             ],
             resources: [ .process("Resources") ]
         ),
+        .testTarget(
+            name: "SmithyCBORTests",
+            dependencies: ["SmithyCBOR", "ClientRuntime", "SmithyTestUtil"]
+        ),
         .testTarget(
             name: "SmithyHTTPClientTests",
             dependencies: [

Tests/SmithyCBORTests/ReaderTests.swift

@@ -0,0 +1,72 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import XCTest
+@testable @_spi(SmithyReadWrite) import SmithyCBOR
+import SmithyTestUtil
+
+class ReaderTests: XCTestCase {
+
+    func test_readsNull() async throws {
+        let cborData = Data()
+        let reader = try SmithyCBOR.Reader.from(data: cborData)
+        XCTAssertEqual(reader.cborValue, .null)
+    }
+
+    func test_compare_nulls() async throws {
+        let cborData1 = Data()
+        let cborData2 = Data()
+        XCTAssertTrue(try CBORComparator.cborData(cborData1, isEqualTo: cborData2))
+    }
+
+    func test_compare_complex() async throws {
+        // cborData1 is semantically different from cborData2, but logically equivalent (reordered keys in the map)
+        let cborData1 = Data([
+            0xBF, // Start of outer indefinite-length map
+
+            // Key: "defaults"
+            0x68, 0x64, 0x65, 0x66, 0x61, 0x75, 0x6C, 0x74, 0x73,
+            0xBF, // Start of "defaults" map
+
+                // Key: "customString"
+                0x6C, 0x63, 0x75, 0x73, 0x74, 0x6F, 0x6D, 0x53, 0x74, 0x72, 0x69, 0x6E, 0x67,
+                // Indefinite-length string for "hello"
+                0x7F, 0x65, 0x68, 0x65, 0x6C, 0x6C, 0x6F, 0xFF,
+
+                // Key: "defaultString"
+                0x6D, 0x64, 0x65, 0x66, 0x61, 0x75, 0x6C, 0x74,
+                0x53, 0x74, 0x72, 0x69, 0x6E, 0x67,
+                // Indefinite-length string for "hi"
+                0x7F, 0x62, 0x68, 0x69, 0xFF,
+
+            0xFF, // End of the "defaults" map
+            0xFF  // End of indefinite-length map
+        ])
+        let cborData2 = Data([
+            0xBF, // Start of outer indefinite-length map
+
+            // Key: "defaults"
+            0x68, 0x64, 0x65, 0x66, 0x61, 0x75, 0x6C, 0x74, 0x73,
+            0xBF, // Start of "defaults" map
+
+                // Key: "defaultString"
+                0x6D, 0x64, 0x65, 0x66, 0x61, 0x75, 0x6C, 0x74,
+                0x53, 0x74, 0x72, 0x69, 0x6E, 0x67,
+                // Indefinite-length string for "hi"
+                0x7F, 0x62, 0x68, 0x69, 0xFF,
+
+                // Key: "customString"
+                0x6C, 0x63, 0x75, 0x73, 0x74, 0x6F, 0x6D, 0x53, 0x74, 0x72, 0x69, 0x6E, 0x67,
+                // Indefinite-length string for "hello"
+                0x7F, 0x65, 0x68, 0x65, 0x6C, 0x6C, 0x6F, 0xFF,
+
+            0xFF, // End of the "defaults" map
+            0xFF  // End of indefinite-length map
+        ])
+        XCTAssertTrue(try CBORComparator.cborData(cborData1, isEqualTo: cborData2))
+    }
+}