Fix issue with FileSink not closing the stream on hook errors

src/Serilog.Sinks.File/Sinks/File/FileSink.cs

@@ -91,8 +91,16 @@ internal FileSink(
 
         if (hooks != null)
         {
-            outputStream = hooks.OnFileOpened(path, outputStream, encoding) ??
-                           throw new InvalidOperationException($"The file lifecycle hook `{nameof(FileLifecycleHooks.OnFileOpened)}(...)` returned `null`.");
+            try
+            {
+                outputStream = hooks.OnFileOpened(path, outputStream, encoding) ??
+                               throw new InvalidOperationException($"The file lifecycle hook `{nameof(FileLifecycleHooks.OnFileOpened)}(...)` returned `null`.");
+            }
+            catch
+            {
+                outputStream?.Dispose();
+                throw;
+            }
         }
 
         _output = new StreamWriter(outputStream, encoding);

test/Serilog.Sinks.File.Tests/RollingFileSinkTests.cs

@@ -4,6 +4,7 @@
 using Serilog.Sinks.File.Tests.Support;
 using Serilog.Configuration;
 using Serilog.Core;
+using Serilog.Debugging;
 using Xunit.Abstractions;
 
 namespace Serilog.Sinks.File.Tests;
@@ -196,85 +197,71 @@ public void WhenFirstOpeningFailedWithLockRetryDelayed30Minutes()
     {
         var fileName = Some.String() + ".txt";
         using var temp = new TempFolder();
+        using var log = new LoggerConfiguration()
+            .WriteTo.File(Path.Combine(temp.Path, fileName), rollOnFileSizeLimit: true, fileSizeLimitBytes: 1, rollingInterval: RollingInterval.Hour, hooks: new FailOpeningHook(true, 2, 3, 4))
+            .CreateLogger();
         LogEvent e1 = Some.InformationEvent(new DateTime(2012, 10, 28)),
             e2 = Some.InformationEvent(e1.Timestamp.AddSeconds(1)),
             e3 = Some.InformationEvent(e1.Timestamp.AddMinutes(5)),
             e4 = Some.InformationEvent(e1.Timestamp.AddMinutes(31));
         LogEvent[] logEvents = new[] { e1, e2, e3, e4 };
-
-        using (var log = new LoggerConfiguration()
-                   .WriteTo.File(Path.Combine(temp.Path, fileName), rollOnFileSizeLimit: true, fileSizeLimitBytes: 1,
-                       rollingInterval: RollingInterval.Hour, hooks: new FailOpeningHook(true, 2, 3, 4))
-                   .CreateLogger())
+
+        SelfLog.Enable(_testOutputHelper.WriteLine);
+        foreach (var logEvent in logEvents)
         {
-            foreach (var logEvent in logEvents)
-            {
-                Clock.SetTestDateTimeNow(logEvent.Timestamp.DateTime);
-                log.Write(logEvent);
-            }
+            Clock.SetTestDateTimeNow(logEvent.Timestamp.DateTime);
+            log.Write(logEvent);
         }
 
         var files = Directory.GetFiles(temp.Path)
             .OrderBy(p => p, StringComparer.OrdinalIgnoreCase)
             .ToArray();
         var pattern = "yyyyMMddHH";
 
-        foreach (var file in files)
-        {
-            _testOutputHelper.WriteLine(file + ": " + System.IO.File.ReadAllText(file));
-        }
-        Assert.Equal(5, files.Length);
+        Assert.Equal(4, files.Length);
         // Successful write of e1:
         Assert.True(files[0].EndsWith(ExpectedFileName(fileName, e1.Timestamp, pattern)), files[0]);
         // Failing writes for e2, will be dropped and logged to SelfLog; on lock it will try it three times:
         Assert.True(files[1].EndsWith("_001.txt"), files[1]);
         Assert.True(files[2].EndsWith("_002.txt"), files[2]);
-        Assert.True(files[3].EndsWith("_003.txt"), files[3]);
         /* e3 will be dropped and logged to SelfLog without new file as it's in the 30 minutes cooldown and roller only starts on next hour! */
-        // Successful write of e4:
-        Assert.True(files[4].EndsWith("_004.txt"), files[4]);
+        // Successful write of e4, the third file will be retried after failing initially:
+        Assert.True(files[3].EndsWith("_003.txt"), files[3]);
     }
 
     [Fact]
     public void WhenFirstOpeningFailedWithoutLockRetryDelayed30Minutes()
     {
         var fileName = Some.String() + ".txt";
         using var temp = new TempFolder();
+        using var log = new LoggerConfiguration()
+            .WriteTo.File(Path.Combine(temp.Path, fileName), rollOnFileSizeLimit: true, fileSizeLimitBytes: 1, rollingInterval: RollingInterval.Hour, hooks: new FailOpeningHook(false, 2))
+            .CreateLogger();
         LogEvent e1 = Some.InformationEvent(new DateTime(2012, 10, 28)),
             e2 = Some.InformationEvent(e1.Timestamp.AddSeconds(1)),
             e3 = Some.InformationEvent(e1.Timestamp.AddMinutes(5)),
             e4 = Some.InformationEvent(e1.Timestamp.AddMinutes(31));
         LogEvent[] logEvents = new[] { e1, e2, e3, e4 };
-
-        using (var log = new LoggerConfiguration()
-                   .WriteTo.File(Path.Combine(temp.Path, fileName), rollOnFileSizeLimit: true, fileSizeLimitBytes: 1,
-                       rollingInterval: RollingInterval.Hour, hooks: new FailOpeningHook(false, 2))
-                   .CreateLogger())
+
+        SelfLog.Enable(_testOutputHelper.WriteLine);
+        foreach (var logEvent in logEvents)
         {
-            foreach (var logEvent in logEvents)
-            {
-                Clock.SetTestDateTimeNow(logEvent.Timestamp.DateTime);
-                log.Write(logEvent);
-            }
+            Clock.SetTestDateTimeNow(logEvent.Timestamp.DateTime);
+            log.Write(logEvent);
         }
 
         var files = Directory.GetFiles(temp.Path)
             .OrderBy(p => p, StringComparer.OrdinalIgnoreCase)
             .ToArray();
         var pattern = "yyyyMMddHH";
 
-        foreach (var file in files)
-        {
-            _testOutputHelper.WriteLine(file + ": " + System.IO.File.ReadAllText(file));
-        }
-        Assert.Equal(3, files.Length);
+        Assert.Equal(2, files.Length);
         // Successful write of e1:
         Assert.True(files[0].EndsWith(ExpectedFileName(fileName, e1.Timestamp, pattern)), files[0]);
-        // Failing writes for e2, will be dropped and logged to SelfLog; on non-lock it will try it once:
-        Assert.True(files[1].EndsWith("_001.txt"), files[1]);
+        /* Failing writes for e2, will be dropped and logged to SelfLog; on non-lock it will try it once */
         /* e3 will be dropped and logged to SelfLog without new file as it's in the 30 minutes cooldown and roller only starts on next hour! */
-        // Successful write of e4:
-        Assert.True(files[2].EndsWith("_002.txt"), files[2]);
+        // Successful write of e4, the file will be retried after failing initially:
+        Assert.True(files[1].EndsWith("_001.txt"), files[1]);
     }
 
     [Fact]

test/Serilog.Sinks.File.Tests/Support/FailOpeningHook.cs

@@ -19,18 +19,18 @@ public FailOpeningHook(bool asFileLocked, params int[] failingInstances)
         _failingInstances = failingInstances;
     }
 
-    public override Stream OnFileOpened(string path, Stream _, Encoding __)
+    public override Stream OnFileOpened(string path, Stream stream, Encoding encoding)
     {
         TimesOpened++;
         if (_failingInstances.Contains(TimesOpened))
         {
             var message = $"We failed on try {TimesOpened}, the file was locked: {_asFileLocked}";
-            
+
             throw _asFileLocked
                 ? new IOException(message)
                 : new Exception(message);
         }
 
-        return base.OnFileOpened(path, _, __);
+        return base.OnFileOpened(path, stream, encoding);
     }
 }