Invalidate FileInfo and DirectoryInfo upon create and delete

src/libraries/System.IO.FileSystem/src/System/IO/DirectoryInfo.cs

@@ -235,8 +235,12 @@ public void MoveTo(string destDirName)
             Invalidate();
         }
 
-        public override void Delete() => FileSystem.RemoveDirectory(FullPath, recursive: false);
+        public override void Delete() => Delete(recursive: false);
 
-        public void Delete(bool recursive) => FileSystem.RemoveDirectory(FullPath, recursive);
+        public void Delete(bool recursive)
+        {
+            FileSystem.RemoveDirectory(FullPath, recursive);
+            Invalidate();
+        }
     }
 }

src/libraries/System.IO.FileSystem/src/System/IO/FileInfo.cs

@@ -99,9 +99,18 @@ public FileInfo CopyTo(string destFileName, bool overwrite)
             return new FileInfo(destinationPath, isNormalized: true);
         }
 
-        public FileStream Create() => File.Create(NormalizedPath);
+        public FileStream Create()
+        {
+            FileStream fileStream = File.Create(NormalizedPath);
+            Invalidate();
+            return fileStream;
+        }
 
-        public override void Delete() => FileSystem.DeleteFile(FullPath);
+        public override void Delete()
+        {
+            FileSystem.DeleteFile(FullPath);
+            Invalidate();
+        }
 
         public FileStream Open(FileMode mode)
             => Open(mode, (mode == FileMode.Append ? FileAccess.Write : FileAccess.ReadWrite), FileShare.None);

src/libraries/System.IO.FileSystem/tests/Base/InfoGetSetTimes.cs

@@ -49,7 +49,7 @@ public void ExistsThenDelete_ReturnsDefaultValues()
         }
 
         [Fact]
-        public void TimesStillSetAfterDelete()
+        public void TimesResetAfterDelete()
         {
             T item = GetExistingItem();
 
@@ -63,11 +63,13 @@ public void TimesStillSetAfterDelete()
                 times.Add(timeFunction, timeFunction.Getter(item));
             }
 
-            // Deleting shouldn't change any info state
+            // Deleting should refresh state
             item.Delete();
+
             Assert.All(times, time =>
             {
-                Assert.Equal(time.Value, time.Key.Getter(item));
+                // We check that all the file times have been refreshed
+                Assert.NotEqual(time.Key.Getter(item), time.Value);
             });
         }
     }

src/libraries/System.IO.FileSystem/tests/DirectoryInfo/Create.cs

@@ -83,5 +83,14 @@ public void CreateDirectoryWithAttributes()
             testInfo.Create();
             testInfo.Attributes = FileAttributes.Directory | FileAttributes.Normal;
         }
+
+        [Fact]
+        public void CreateInvalidatesDirectoryInfo()
+        {
+            string testDir = Path.Combine(GetTestFilePath(), "DirectoryCreate");
+            DirectoryInfo testDirectoryInfo = new DirectoryInfo(testDir);
+            testDirectoryInfo.Create();
+            Assert.True(testDirectoryInfo.Exists);
+        }
     }
 }

src/libraries/System.IO.FileSystem/tests/DirectoryInfo/Delete.cs

@@ -14,17 +14,14 @@ protected override void Delete(string path)
         }
 
         [Fact]
-        public void ExistsDoesntRefreshOnDelete()
+        public void DeleteInvalidatesDirectoryInfo()
         {
-            DirectoryInfo dir = Directory.CreateDirectory(Path.Combine(TestDirectory, Path.GetRandomFileName()));
-
-            Assert.True(dir.Exists);
-
-            dir.Delete();
-
-            Assert.True(dir.Exists);
-            dir.Refresh();
-            Assert.False(dir.Exists);
+            string testDir = Path.Combine(GetTestFilePath(), "DirectoryCreate");
+            DirectoryInfo testDirectoryInfo = new DirectoryInfo(testDir);
+            testDirectoryInfo.Create();
+            Assert.True(testDirectoryInfo.Exists);
+            testDirectoryInfo.Delete();
+            Assert.False(testDirectoryInfo.Exists);
         }
     }
 

src/libraries/System.IO.FileSystem/tests/FileInfo/Create.cs

@@ -32,6 +32,18 @@ public void FullNameUpdatesOnCreate()
             }
         }
 
+        [Fact]
+        public void FileInfoInvalidAfterCreate()
+        {
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string testFilePath = Path.Combine(testDir.FullName, GetTestFileName());
+            FileInfo info = new FileInfo(testFilePath);
+            using (FileStream fileStream = info.Create())
+            {
+                Assert.True(info.Exists);
+            }
+        }
+
         #endregion
     }
 }

src/libraries/System.IO.FileSystem/tests/FileInfo/Delete.cs

@@ -12,5 +12,20 @@ protected override void Delete(string path)
         {
             new FileInfo(path).Delete();
         }
+
+        [Fact]
+        public void FileInfoInvalidatedOnDelete()
+        {
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string testFilePath = Path.Combine(testDir.FullName, GetTestFileName());
+            FileInfo info = new FileInfo(testFilePath);
+            using (FileStream fileStream = info.Create())
+            {
+                Assert.True(info.Exists);
+            }
+
+            info.Delete();
+            Assert.False(info.Exists);
+        }
     }
 }

src/libraries/System.IO.FileSystem/tests/FileInfo/GetSetTimes.cs

@@ -194,9 +194,8 @@ public void DeleteAfterEnumerate_TimesStillSet()
 
             DateTime afterTime = DateTime.UtcNow.AddSeconds(1);
 
-            // Deleting doesn't change any info state
             info.Delete();
-            ValidateSetTimes(info, beforeTime, afterTime);
+            Assert.Equal(DateTime.FromFileTimeUtc(0), info.LastAccessTimeUtc);
         }