Read .NET driver log files with shared access

examples/dotnet/SeleniumDocs/Browsers/ChromeTest.cs

@@ -25,7 +25,7 @@ public void Cleanup()
             driver?.Quit();
             if (_logLocation != null && File.Exists(_logLocation))
             {
-                File.Delete(_logLocation);
+                LogFile.TryDelete(_logLocation);
             }
         }
 
@@ -108,7 +108,7 @@ public void LogsToFile()
 
             driver = new ChromeDriver(service);
             driver.Quit(); // Close the Service log file before reading
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             Assert.IsNotNull(lines.FirstOrDefault(line => line.Contains("Starting ChromeDriver")));
         }
 
@@ -123,7 +123,7 @@ public void LogsLevel()
             driver = new ChromeDriver(service);
 
             driver.Quit(); // Close the Service log file before reading
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             Assert.IsNotNull(lines.FirstOrDefault(line => line.Contains("[DEBUG]:")));
         }
 
@@ -140,7 +140,7 @@ public void ConfigureDriverLogs()
             driver = new ChromeDriver(service);
 
             driver.Quit(); // Close the Service log file before reading
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             var regex = new Regex(@"\[\d\d-\d\d-\d\d\d\d \d\d:\d\d:\d\d\.\d+\]");
             Assert.IsNotNull(lines.FirstOrDefault(line => regex.Matches(line).Count > 0));
         }
@@ -157,7 +157,7 @@ public void DisableBuildCheck()
             driver = new ChromeDriver(service);
             driver.Quit(); // Close the Service log file before reading
             var expected = "[WARNING]: You are using an unsupported command-line switch: --disable-build-check";
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             Assert.IsNotNull(lines.FirstOrDefault(line => line.Contains(expected)));
         }
 

examples/dotnet/SeleniumDocs/Browsers/EdgeTest.cs

@@ -173,15 +173,15 @@ private static string[] ReadLogLines(string path)
             {
                 try
                 {
-                    return File.ReadAllLines(path);
+                    return LogFile.ReadLines(path);
                 }
                 catch (IOException) when (attempt < maxAttempts)
                 {
                     Thread.Sleep(500);
                 }
             }
 
-            return File.ReadAllLines(path);
+            return LogFile.ReadLines(path);
         }
 
         private string GetLogLocation()

examples/dotnet/SeleniumDocs/Browsers/FirefoxTest.cs

@@ -22,7 +22,7 @@ public void Cleanup()
             driver?.Quit();
             if (!String.IsNullOrEmpty(_logLocation) && File.Exists(_logLocation))
             {
-                File.Delete(_logLocation);
+                LogFile.TryDelete(_logLocation);
             }
             if (_tempPath != null && Directory.Exists(_tempPath))
             {
@@ -65,7 +65,7 @@ public void LogsToFile()
 
             driver = new FirefoxDriver(service);
             driver.Quit(); // Close the Service log file before reading
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             Assert.IsNotNull(lines.FirstOrDefault(line => line.Contains("geckodriver	INFO	Listening on")));
         }
 
@@ -97,7 +97,7 @@ public void LogsLevel()
 
             driver = new FirefoxDriver(service);
             driver.Quit(); // Close the Service log file before reading
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             Assert.IsNotNull(lines.FirstOrDefault(line => line.Contains("Marionette\tDEBUG")));
         }
 
@@ -111,7 +111,7 @@ public void StopsTruncatingLogs()
 
             driver = new FirefoxDriver(service);
             driver.Quit(); // Close the Service log file before reading
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             Assert.IsNull(lines.FirstOrDefault(line => line.Contains(" ... ")));
         }
 

examples/dotnet/SeleniumDocs/Browsers/InternetExplorerTest.cs

@@ -21,7 +21,7 @@ public void Cleanup()
             _driver?.Quit();
             if (_logLocation != null && File.Exists(_logLocation))
             {
-                File.Delete(_logLocation);
+                LogFile.TryDelete(_logLocation);
             }
             if (_tempPath != null && File.Exists(_tempPath))
             {
@@ -55,7 +55,7 @@ public void LogsLevel()
 
             _driver = new InternetExplorerDriver(service);
             _driver.Quit(); // Close the Service log file before reading
-            var lines = File.ReadLines(GetLogLocation());
+            var lines = LogFile.ReadLines(GetLogLocation());
             Assert.IsNotNull(lines.FirstOrDefault(line => line.Contains("Invalid capability setting: timeouts is type null")));
         }
 

examples/dotnet/SeleniumDocs/LogFile.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading;
+
+namespace SeleniumDocs
+{
+    // Driver log files can still be open by the driver process after Quit(),
+    // especially on Windows. Share the file instead of requesting exclusive access.
+    public static class LogFile
+    {
+        public static string[] ReadLines(string path)
+        {
+            using var stream = new FileStream(path, FileMode.Open, FileAccess.Read,
+                FileShare.ReadWrite | FileShare.Delete);
+            using var reader = new StreamReader(stream);
+            var lines = new List<string>();
+            string line;
+            while ((line = reader.ReadLine()) != null)
+            {
+                lines.Add(line);
+            }
+            return lines.ToArray();
+        }
+
+        public static void TryDelete(string path)
+        {
+            const int maxAttempts = 10;
+            for (var attempt = 1; attempt <= maxAttempts; attempt++)
+            {
+                try
+                {
+                    File.Delete(path);
+                    return;
+                }
+                catch (IOException) when (attempt < maxAttempts)
+                {
+                    // Still held by the driver process; give it time to exit.
+                    Thread.Sleep(200);
+                }
+                catch (IOException e)
+                {
+                    Console.Error.WriteLine($"Could not delete driver log {path}: {e.Message}");
+                }
+            }
+        }
+    }
+}