Prompt to kill locking processes when accepting

docs/mdsource/tray.source.md

@@ -49,6 +49,18 @@ Clicking "file1" or "file2" will delete file1 or file2 respectively. The drop do
 "Accept all" will accept all pending moves and all pending deletes.
 
 
+### Locked files
+
+If accepting a move fails because the files are locked by another process (for example the snapshot is open in Microsoft Word), a prompt is shown listing the locked files and the locking processes:
+
+<img src="..\src\DiffEngineTray.Tests\LockedFilesFormTests.Default.verified.png">
+
+ * "Ignore" leaves the move pending so it can be accepted later.
+ * "Kill [process] and accept" kills the locking processes and accepts the move.
+ * "Kill and accept all pending" kills the locking processes and accepts all pending moves, killing any other locking processes without further prompts.
+ * "Always kill" kills the locking processes and accepts the move. The choice is stored in settings, so future locked files are killed without prompting. It can be toggled in the Options dialog.
+
+
 ### Discard
 
 Discard will clear all currently tracked items.
@@ -79,6 +91,11 @@ By default, when a diff is opened, the temp file will be on the left and the tar
 Control the [max instances to launch setting](docs/diff-tool.md#maxinstancestolaunch).
 
 
+#### Always kill locking processes
+
+When accepting a move with [locked files](#locked-files), kill the locking processes without prompting.
+
+
 #### Discard all HotKey
 
 Registers a system wide HotKey to discard pending:

docs/tray.md

@@ -56,6 +56,18 @@ Clicking "file1" or "file2" will delete file1 or file2 respectively. The drop do
 "Accept all" will accept all pending moves and all pending deletes.
 
 
+### Locked files
+
+If accepting a move fails because the files are locked by another process (for example the snapshot is open in Microsoft Word), a prompt is shown listing the locked files and the locking processes:
+
+<img src="..\src\DiffEngineTray.Tests\LockedFilesFormTests.Default.verified.png">
+
+ * "Ignore" leaves the move pending so it can be accepted later.
+ * "Kill [process] and accept" kills the locking processes and accepts the move.
+ * "Kill and accept all pending" kills the locking processes and accepts all pending moves, killing any other locking processes without further prompts.
+ * "Always kill" kills the locking processes and accepts the move. The choice is stored in settings, so future locked files are killed without prompting. It can be toggled in the Options dialog.
+
+
 ### Discard
 
 Discard will clear all currently tracked items.
@@ -86,6 +98,11 @@ By default, when a diff is opened, the temp file will be on the left and the tar
 Control the [max instances to launch setting](docs/diff-tool.md#maxinstancestolaunch).
 
 
+#### Always kill locking processes
+
+When accepting a move with [locked files](#locked-files), kill the locking processes without prompting.
+
+
 #### Discard all HotKey
 
 Registers a system wide HotKey to discard pending:

src/DiffEngineTray.Tests/FileLockKillerTest.cs

@@ -1,5 +1,44 @@
 public class FileLockKillerTest
 {
+    [Test]
+    public async Task GetLockingProcesses_WhenFileNotLocked_ReturnsEmpty()
+    {
+        var file = Path.Combine(Path.GetTempPath(), $"FileLockKillerTest_{Guid.NewGuid()}.txt");
+        try
+        {
+            File.WriteAllText(file, "content");
+            var result = FileLockKiller.GetLockingProcesses(file);
+            await Assert.That(result).IsEmpty();
+        }
+        finally
+        {
+            File.Delete(file);
+        }
+    }
+
+    [Test]
+    public async Task GetLockingProcesses_WhenFileLocked_ReturnsProcess()
+    {
+        var file = Path.Combine(Path.GetTempPath(), $"FileLockKillerTest_{Guid.NewGuid()}.txt");
+        File.WriteAllText(file, "content");
+
+        var lockProcess = FileLockUtils.StartFileLockProcess(file);
+
+        try
+        {
+            await Assert.That(FileLockUtils.IsFileLocked(file)).IsTrue();
+
+            var result = FileLockKiller.GetLockingProcesses(file);
+
+            await Assert.That(result.Select(_ => _.ProcessId)).Contains(lockProcess.Id);
+        }
+        finally
+        {
+            FileLockUtils.Cleanup(lockProcess);
+            File.Delete(file);
+        }
+    }
+
     [Test]
     public async Task KillLockingProcesses_WhenFileNotLocked_ReturnsFalse()
     {
@@ -30,11 +69,11 @@ public async Task KillLockingProcesses_WhenFileLocked_KillsProcess()
         var file = Path.Combine(Path.GetTempPath(), $"FileLockKillerTest_{Guid.NewGuid()}.txt");
         File.WriteAllText(file, "content");
 
-        var lockProcess = StartFileLockProcess(file);
+        var lockProcess = FileLockUtils.StartFileLockProcess(file);
 
         try
         {
-            await Assert.That(IsFileLocked(file)).IsTrue();
+            await Assert.That(FileLockUtils.IsFileLocked(file)).IsTrue();
 
             var result = FileLockKiller.KillLockingProcesses(file);
 
@@ -45,12 +84,7 @@ public async Task KillLockingProcesses_WhenFileLocked_KillsProcess()
         }
         finally
         {
-            if (!lockProcess.HasExited)
-            {
-                lockProcess.Kill();
-            }
-
-            lockProcess.Dispose();
+            FileLockUtils.Cleanup(lockProcess);
             File.Delete(file);
         }
     }
@@ -63,11 +97,11 @@ public async Task MoveSucceedsAfterKillingLockingProcess()
         File.WriteAllText(file, "content");
         File.WriteAllText(tempFile, "new content");
 
-        var lockProcess = StartFileLockProcess(file);
+        var lockProcess = FileLockUtils.StartFileLockProcess(file);
 
         try
         {
-            await Assert.That(IsFileLocked(file)).IsTrue();
+            await Assert.That(FileLockUtils.IsFileLocked(file)).IsTrue();
             await Assert.That(FileEx.SafeMove(tempFile, file)).IsFalse();
 
             FileLockKiller.KillLockingProcesses(file);
@@ -77,53 +111,9 @@ public async Task MoveSucceedsAfterKillingLockingProcess()
         }
         finally
         {
-            if (!lockProcess.HasExited)
-            {
-                lockProcess.Kill();
-            }
-
-            lockProcess.Dispose();
+            FileLockUtils.Cleanup(lockProcess);
             File.Delete(file);
             File.Delete(tempFile);
         }
     }
-
-    static Process StartFileLockProcess(string path)
-    {
-        var script = $"$f = [System.IO.File]::Open('{path.Replace("'", "''")}', 'Open', 'ReadWrite', 'None'); [Console]::WriteLine('locked'); Start-Sleep -Seconds 60";
-        var process = new Process
-        {
-            StartInfo = new()
-            {
-                FileName = "powershell.exe",
-                Arguments = $"-NoProfile -Command \"{script}\"",
-                UseShellExecute = false,
-                CreateNoWindow = true,
-                RedirectStandardOutput = true
-            }
-        };
-        process.Start();
-
-        // Wait for the process to signal that it has acquired the lock
-        var line = process.StandardOutput.ReadLine();
-        if (line != "locked")
-        {
-            throw new InvalidOperationException($"Expected 'locked' but got '{line}'");
-        }
-
-        return process;
-    }
-
-    static bool IsFileLocked(string path)
-    {
-        try
-        {
-            using var stream = File.Open(path, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
-            return false;
-        }
-        catch (IOException)
-        {
-            return true;
-        }
-    }
-}
+}

src/DiffEngineTray.Tests/FileLockUtils.cs

@@ -0,0 +1,52 @@
+static class FileLockUtils
+{
+    public static Process StartFileLockProcess(string path)
+    {
+        var script = $"$f = [System.IO.File]::Open('{path.Replace("'", "''")}', 'Open', 'ReadWrite', 'None'); [Console]::WriteLine('locked'); Start-Sleep -Seconds 60";
+        var process = new Process
+        {
+            StartInfo = new()
+            {
+                FileName = "powershell.exe",
+                Arguments = $"-NoProfile -Command \"{script}\"",
+                UseShellExecute = false,
+                CreateNoWindow = true,
+                RedirectStandardOutput = true
+            }
+        };
+        process.Start();
+
+        // Wait for the process to signal that it has acquired the lock
+        var line = process.StandardOutput.ReadLine();
+        if (line != "locked")
+        {
+            throw new InvalidOperationException($"Expected 'locked' but got '{line}'");
+        }
+
+        return process;
+    }
+
+    public static bool IsFileLocked(string path)
+    {
+        try
+        {
+            using var stream = File.Open(path, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
+            return false;
+        }
+        catch (IOException)
+        {
+            return true;
+        }
+    }
+
+    public static void Cleanup(Process process)
+    {
+        if (!process.HasExited)
+        {
+            process.Kill();
+            process.WaitForExit(5000);
+        }
+
+        process.Dispose();
+    }
+}

src/DiffEngineTray.Tests/LockedFilesFormTests.cs

@@ -0,0 +1,38 @@
+#if DEBUG
+public class LockedFilesFormTests
+{
+    //[Test]
+    //[Explicit]
+    //public void Launch()
+    //{
+    //    using var form = new LockedFilesForm(BuildMove(), BuildLocked());
+    //    form.ShowDialog();
+    //}
+
+    [Test]
+    public async Task Default()
+    {
+        using var form = new LockedFilesForm(BuildMove(), BuildLocked());
+        await Verify(form);
+    }
+
+    static TrackedMove BuildMove() =>
+        new(
+            @"C:\tests\AdviceSummaryTests.BuildWord.received.docx",
+            @"C:\tests\AdviceSummaryTests.BuildWord.verified.docx",
+            null,
+            null,
+            false,
+            null,
+            null,
+            "docx");
+
+    static LockedFiles BuildLocked() =>
+        new(
+            [
+                @"C:\tests\AdviceSummaryTests.BuildWord.received.docx",
+                @"C:\tests\AdviceSummaryTests.BuildWord.verified.docx"
+            ],
+            [new(1234, "Microsoft Word")]);
+}
+#endif

src/DiffEngineTray.Tests/RecordingTracker.cs

@@ -1,16 +1,17 @@
-class RecordingTracker() :
+class RecordingTracker(LockedFilesResolver? lockedFilesResolver = null) :
     Tracker(
         () =>
         {
         },
         () =>
         {
-        })
+        },
+        lockedFilesResolver)
 {
     public async Task AssertEmpty()
     {
         await Assert.That(Deletes).IsEmpty();
         await Assert.That(Moves).IsEmpty();
         await Assert.That(TrackingAny).IsFalse();
     }
-}
+}

src/DiffEngineTray.Tests/SettingsHelperTests.ReadWrite.verified.txt

@@ -6,6 +6,7 @@
     Key: T
   },
   RunAtStartup: false,
+  AlwaysKillLockingProcesses: true,
   TargetOnLeft: false,
   MaxInstancesToLaunch: 5
 }

src/DiffEngineTray.Tests/SettingsHelperTests.cs

@@ -20,7 +20,8 @@ await SettingsHelper.Write(
                         Key = "T"
                     },
                     MaxInstancesToLaunch = 5,
-                    TargetOnLeft = false
+                    TargetOnLeft = false,
+                    AlwaysKillLockingProcesses = true
                 });
 
             var result = await SettingsHelper.Read();