Merge pull request #2655 from nguerrera/fix-fsw-linux-test

Fix FileSystemWatcher test race and allow process exit time == start time

Author: stephentoub

src/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests/ProcessTests.cs

@@ -137,7 +137,7 @@ public void TestExitTime()
             Assert.Throws<InvalidOperationException>(() => p.ExitTime);
             p.Kill();
             Assert.True(p.WaitForExit(WaitInMS));
-            Assert.True(p.ExitTime.ToUniversalTime() > timeBeforeProcessStart, "TestExitTime is incorrect.");
+            Assert.True(p.ExitTime.ToUniversalTime() >= timeBeforeProcessStart, "TestExitTime is incorrect.");
         }
 
         [Fact]

src/System.IO.FileSystem.Watcher/tests/FileSystemWatcher.Created.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.InteropServices;
 using System.Threading;
 using Xunit;
 
@@ -101,7 +102,14 @@ public static void FileSystemWatcher_Created_Negative()
                 testFile.Flush();
 
                 // renaming a directory
-                testDir.Move(testDir.Path + "_rename");
+                //
+                // We don't do this on Linux because depending on the timing of MOVED_FROM and MOVED_TO events,
+                // a rename can trigger delete + create as a deliberate handling of an edge case, and this
+                // test is checking that no create events are raised.
+                if (!RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+                {
+                    testDir.Move(testDir.Path + "_rename");
+                }
 
                 // deleting a file & directory by leaving the using block
             }

src/System.IO.FileSystem.Watcher/tests/FileSystemWatcher.Deleted.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.IO;
+using System.Runtime.InteropServices;
 using System.Threading;
 using Xunit;
 
@@ -70,9 +71,16 @@ public static void FileSystemWatcher_Deleted_Negative()
                 testFile.Flush();
 
                 // renaming a directory
-                testDir.Move(testDir.Path + "_rename");
+                //
+                // We don't do this on Linux because depending on the timing of MOVED_FROM and MOVED_TO events,
+                // a rename can trigger delete + create as a deliberate handling of an edge case, and this
+                // test is checking that no delete events are raised.
+                if (!RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+                {
+                    testDir.Move(testDir.Path + "_rename");
+                }
 
-                Utility.ExpectNoEvent(eventOccured, "changed");
+                Utility.ExpectNoEvent(eventOccured, "deleted");
             }
         }
     }