chore: import upstream snapshot with attribution

test/fd_guard_unittest.cpp

@@ -0,0 +1,77 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include <sys/types.h>                          // open
+#include <sys/stat.h>                           // ^
+#include <fcntl.h>                              // ^
+#include <gtest/gtest.h>
+#include <errno.h>
+#include "butil/fd_guard.h"
+
+namespace {
+
+class FDGuardTest : public ::testing::Test{
+protected:
+    FDGuardTest(){
+    };
+    virtual ~FDGuardTest(){};
+    virtual void SetUp() {
+    };
+    virtual void TearDown() {
+    };
+};
+
+TEST_F(FDGuardTest, default_constructor) {
+    butil::fd_guard guard;
+    ASSERT_EQ(-1, guard);
+}
+
+TEST_F(FDGuardTest, destructor_closes_fd) {
+    int fd = -1;
+    {
+        butil::fd_guard guard(open(".tmp1",  O_WRONLY|O_CREAT, 0600));
+        ASSERT_GT(guard, 0);
+        fd = guard;
+    }
+    char dummy = 0;
+    ASSERT_EQ(-1L, write(fd, &dummy, 1));
+    ASSERT_EQ(EBADF, errno);
+}
+
+TEST_F(FDGuardTest, reset_closes_previous_fd) {
+    butil::fd_guard guard(open(".tmp1",  O_WRONLY|O_CREAT, 0600));
+    ASSERT_GT(guard, 0);
+    const int fd = guard;
+    const int fd2 = open(".tmp2",  O_WRONLY|O_CREAT, 0600);
+    guard.reset(fd2);
+    char dummy = 0;
+    ASSERT_EQ(-1L, write(fd, &dummy, 1));
+    ASSERT_EQ(EBADF, errno);
+    guard.reset(-1);
+    ASSERT_EQ(-1L, write(fd2, &dummy, 1));
+    ASSERT_EQ(EBADF, errno);
+}
+    
+TEST_F(FDGuardTest, release) {
+    butil::fd_guard guard(open(".tmp1",  O_WRONLY|O_CREAT, 0600));
+    ASSERT_GT(guard, 0);
+    const int fd = guard;
+    ASSERT_EQ(fd, guard.release());
+    ASSERT_EQ(-1, guard);
+    close(fd);
+}
+}