public async Task SetLogFile_PurgesOldLogFiles()
{
var directory = new DirectoryInfo(_logFilePath);
directory.Create();
// below test expects the retention days to be set to 1
Assert.Equal(1, FileWriter.LastModifiedCutoffDays);
// create some log files
var logFiles = new List <FileInfo>();
for (int i = 0; i < 5; i++)
{
string fileName = string.Format("{0}-{1}.log", i, FileWriter.GetInstanceId());
string path = Path.Combine(_logFilePath, fileName);
File.WriteAllText(path, "Test Logs");
logFiles.Add(new FileInfo(path));
}
// push all but the last file over size limit
string maxLog = TestHelpers.NewRandomString((int)FileWriter.MaxLogFileSizeBytes + 1);
File.AppendAllText(logFiles[3].FullName, maxLog);
File.AppendAllText(logFiles[2].FullName, maxLog);
File.AppendAllText(logFiles[1].FullName, maxLog);
File.AppendAllText(logFiles[0].FullName, maxLog);
// mark all the files as old to simulate the passage of time
File.SetLastWriteTime(logFiles[4].FullName, DateTime.Now.Subtract(TimeSpan.FromDays(2)));
File.SetLastWriteTime(logFiles[3].FullName, DateTime.Now.Subtract(TimeSpan.FromDays(2)));
File.SetLastWriteTime(logFiles[2].FullName, DateTime.Now.Subtract(TimeSpan.FromDays(3)));
File.SetLastWriteTime(logFiles[1].FullName, DateTime.Now.Subtract(TimeSpan.FromDays(4)));
File.SetLastWriteTime(logFiles[0].FullName, DateTime.Now.Subtract(TimeSpan.FromDays(5)));
var files = directory.GetFiles().OrderByDescending(p => p.LastWriteTime).ToArray();
Assert.Equal(5, files.Length);
// now cause a new log file to be created by writing a huge
// log pushing the current file over limit
var fileWriter = new FileWriter(_logFilePath);
fileWriter.AppendLine(maxLog);
// wait for the new file to be created and the old files to be purged
await TestHelpers.Await(() =>
{
files = directory.GetFiles().OrderByDescending(p => p.LastWriteTime).ToArray();
return(files.Length == 2);
}, timeout : 5000);
// expect only 2 files to remain - the new file we just created, as well
// as the oversize file we just wrote to last (it has a new timestamp now so
// wasn't purged)
Assert.True(files[1].Length > FileWriter.MaxLogFileSizeBytes);
// expect the new file to be empty because everything was flushed
// to the previous file before it was created
var fileLines = File.ReadAllLines(files[0].FullName);
Assert.Equal(0, fileLines.Length);
// make sure the new log is written to the new file
fileWriter.AppendLine("test message");
fileWriter.Flush();
fileLines = File.ReadAllLines(files[0].FullName);
Assert.Equal(1, fileLines.Length);
}
