[lldb-dap] Adding unittests for Transport.

This adds basic support for testing the Transport class and includes tests for 'Read'.

Author: ashgti

lldb/unittests/DAP/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_lldb_unittest(DAPTests
   JSONUtilsTest.cpp
   LLDBUtilsTest.cpp
+  TransportTest.cpp
   ProtocolTypesTest.cpp
 
   LINK_LIBS

lldb/unittests/DAP/TransportTest.cpp

@@ -0,0 +1,81 @@
+//===-- LLDBUtilsTest.cpp -------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Transport.h"
+#include "Protocol/ProtocolBase.h"
+#include "lldb/Host/File.h"
+#include "lldb/Host/Pipe.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gtest/gtest.h"
+#include <chrono>
+#include <memory>
+#include <optional>
+
+using namespace llvm;
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_dap;
+using namespace lldb_dap::protocol;
+
+class TransportTest : public testing::Test {
+protected:
+  Pipe input;
+  Pipe output;
+  std::unique_ptr<Transport> transport;
+
+  void SetUp() override {
+    ASSERT_THAT_ERROR(input.CreateNew(false).ToError(), llvm::Succeeded());
+    ASSERT_THAT_ERROR(output.CreateNew(false).ToError(), llvm::Succeeded());
+    transport = std::make_unique<Transport>(
+        "stdio", nullptr,
+        std::make_shared<NativeFile>(input.GetReadFileDescriptor(),
+                                     File::eOpenOptionReadOnly,
+                                     NativeFile::Unowned),
+        std::make_shared<NativeFile>(output.GetWriteFileDescriptor(),
+                                     File::eOpenOptionWriteOnly,
+                                     NativeFile::Unowned));
+  }
+
+  void Write(StringRef json) {
+    std::string message =
+        formatv("Content-Length: {0}\r\n\r\n{1}", json.size(), json).str();
+    ASSERT_THAT_EXPECTED(input.Write(message.data(), message.size()),
+                         Succeeded());
+  }
+};
+
+TEST_F(TransportTest, MalformedRequests) {
+  std::string malformed_header = "COnTent-LenGth: -1{}\r\n\r\nnotjosn";
+  ASSERT_THAT_EXPECTED(
+      input.Write(malformed_header.data(), malformed_header.size()),
+      Succeeded());
+  ASSERT_THAT_EXPECTED(
+      transport->Read(std::chrono::milliseconds(1)),
+      FailedWithMessage(
+          "expected 'Content-Length: ' and got 'COnTent-LenGth: '"));
+}
+
+TEST_F(TransportTest, Read) {
+  Write(R"json({"seq": 1, "type": "request", "command": "abc"})json");
+  ASSERT_THAT_EXPECTED(transport->Read(std::chrono::milliseconds(1)),
+                       HasValue(testing::VariantWith<Request>(
+                           testing::FieldsAre(1, "abc", std::nullopt))));
+}
+
+TEST_F(TransportTest, ReadWithTimeout) {
+  ASSERT_THAT_EXPECTED(transport->Read(std::chrono::milliseconds(1)),
+                       Failed<TimeoutError>());
+}
+
+TEST_F(TransportTest, ReadWithEOF) {
+  input.CloseWriteFileDescriptor();
+  ASSERT_THAT_EXPECTED(transport->Read(std::chrono::milliseconds(1)),
+                       Failed<EndOfFileError>());
+}