public async Task FileChangeDetectTest() { using var hashAlgorithm = System.Security.Cryptography.SHA1.Create(); using var testStream = new MemoryStream(new byte[] { 1, 2, 3 }); using var writer = new StreamWriter(testStream); using var hashStream = new MemoryStream(hashAlgorithm.ComputeHash(new byte[] { 1, 2, 3 })); var changeDetector = new ChangeDetector(hashAlgorithm); Assert.Null(await changeDetector.DetectAsync(file: testStream, hash: hashStream).ConfigureAwait(false)); testStream.Position = 0; await writer.WriteAsync('.').ConfigureAwait(false); await writer.FlushAsync().ConfigureAwait(false); Assert.NotNull(await changeDetector.DetectAsync(file: testStream, hash: hashStream).ConfigureAwait(false)); }