added unit tests for MallocMapping

Author: gaaclarke

ci/licenses_golden/licenses_flutter

@@ -170,6 +170,7 @@ FILE: ../../../flutter/fml/macros.h
 FILE: ../../../flutter/fml/make_copyable.h
 FILE: ../../../flutter/fml/mapping.cc
 FILE: ../../../flutter/fml/mapping.h
+FILE: ../../../flutter/fml/mapping_unittests.cc
 FILE: ../../../flutter/fml/memory/ref_counted.h
 FILE: ../../../flutter/fml/memory/ref_counted_internal.h
 FILE: ../../../flutter/fml/memory/ref_counted_unittest.cc

fml/BUILD.gn

@@ -252,6 +252,7 @@ if (enable_unittests) {
       "file_unittest.cc",
       "hash_combine_unittests.cc",
       "logging_unittests.cc",
+      "mapping_unittests.cc",
       "memory/ref_counted_unittest.cc",
       "memory/task_runner_checker_unittest.cc",
       "memory/weak_ptr_unittest.cc",

fml/mapping_unittests.cc

@@ -0,0 +1,55 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "flutter/fml/mapping.h"
+#include "flutter/testing/testing.h"
+
+namespace fml {
+
+TEST(MallocMapping, EmptyContructor) {
+  MallocMapping mapping;
+  ASSERT_EQ(nullptr, mapping.GetMapping());
+  ASSERT_EQ(0u, mapping.GetSize());
+}
+
+TEST(MallocMapping, NotEmptyContructor) {
+  size_t length = 10;
+  MallocMapping mapping(reinterpret_cast<uint8_t*>(malloc(length)), length);
+  ASSERT_NE(nullptr, mapping.GetMapping());
+  ASSERT_EQ(length, mapping.GetSize());
+}
+
+TEST(MallocMapping, MoveConstructor) {
+  size_t length = 10;
+  MallocMapping mapping(reinterpret_cast<uint8_t*>(malloc(length)), length);
+  MallocMapping moved = std::move(mapping);
+
+  ASSERT_EQ(nullptr, mapping.GetMapping());
+  ASSERT_EQ(0u, mapping.GetSize());
+  ASSERT_NE(nullptr, moved.GetMapping());
+  ASSERT_EQ(length, moved.GetSize());
+}
+
+TEST(MallocMapping, Copy) {
+  size_t length = 10;
+  MallocMapping mapping(reinterpret_cast<uint8_t*>(malloc(length)), length);
+  memset(const_cast<uint8_t*>(mapping.GetMapping()), 0xac, mapping.GetSize());
+  MallocMapping copied =
+      MallocMapping::Copy(mapping.GetMapping(), mapping.GetSize());
+
+  ASSERT_NE(mapping.GetMapping(), copied.GetMapping());
+  ASSERT_EQ(mapping.GetSize(), copied.GetSize());
+  ASSERT_EQ(
+      0, memcmp(mapping.GetMapping(), copied.GetMapping(), mapping.GetSize()));
+}
+
+TEST(MallocMapping, Release) {
+  size_t length = 10;
+  MallocMapping mapping(reinterpret_cast<uint8_t*>(malloc(length)), length);
+  free(const_cast<uint8_t*>(mapping.Release()));
+  ASSERT_EQ(nullptr, mapping.GetMapping());
+  ASSERT_EQ(0u, mapping.GetSize());
+}
+
+}  // namespace fml