[test] test Span.bytes

Author: glessard

test/stdlib/Span/SpanBytesProperty.swift

@@ -0,0 +1,39 @@
+//===--- SpanBytesProperty.swift --- test Span's bytes property -----------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+// RUN: %target-run-stdlib-swift
+
+// REQUIRES: executable_test
+
+import Swift
+import StdlibUnittest
+
+var suite = TestSuite("SpanBytesProperty")
+defer { runAllTests() }
+
+suite.test("Span/bytes property")
+.skip(.custom(
+  { if #available(SwiftStdlib 6.2, *) { false } else { true } },
+  reason: "Requires Swift 6.2's standard library"
+))
+.code {
+  guard #available(SwiftStdlib 6.2, *) else { return }
+
+  let capacity = 4
+  let a = ContiguousArray(0..<capacity)
+  a.withUnsafeBufferPointer {
+    let bytes = $0.span.bytes
+
+    expectEqual(bytes.byteCount, capacity*MemoryLayout<Int>.stride)
+    expectEqual(bytes.unsafeLoad(fromByteOffset: 3, as: UInt8.self), 0)
+  }
+}