Support MSIX .appinstaller updates for FW Lite testers

backend/FwLite/FwLiteMaui/Platforms/Windows/AppUpdateService.cs

@@ -1,4 +1,5 @@
 using System.Text.Json;
+using Windows.Foundation;
 using Windows.Management.Deployment;
 using Windows.Networking.Connectivity;
 using LexCore.Entities;
@@ -107,13 +108,31 @@ private async Task<UpdateResult> ApplyUpdate(FwLiteRelease latestRelease, bool q
     {
         logger.LogInformation("Installing new version: {Version}, Current version: {CurrentVersion}", latestRelease.Version, AppVersion.Version);
         var packageManager = new PackageManager();
-        var asyncOperation = packageManager.AddPackageByUriAsync(new Uri(latestRelease.Url),
-            new AddPackageOptions()
-            {
-                DeferRegistrationWhenPackagesAreInUse = true,
-                ForceUpdateFromAnyVersion = true,
-                ForceAppShutdown = quitOnUpdate
-            });
+
+        //If this install is associated with an .appinstaller file, it's on the OS update track and we
+        //must update through the App Installer API. Updating the raw bundle via AddPackageByUriAsync
+        //would detach it from that track (see App Installer non-store update docs). Installs from a plain
+        //.msixbundle - how most users are installed today - have no association and take the fallback path.
+        var appInstallerUri = GetAppInstallerUri();
+        IAsyncOperationWithProgress<DeploymentResult, DeploymentProgress> asyncOperation;
+        if (appInstallerUri is not null)
+        {
+            logger.LogInformation("Updating via App Installer file {AppInstallerUri}", appInstallerUri);
+            //ForceUpdateFromAnyVersion is controlled by the .appinstaller XML, not these options.
+            asyncOperation = packageManager.AddPackageByAppInstallerFileAsync(appInstallerUri,
+                quitOnUpdate ? AddPackageByAppInstallerOptions.ForceTargetAppShutdown : AddPackageByAppInstallerOptions.None,
+                packageManager.GetDefaultPackageVolume());
+        }
+        else
+        {
+            asyncOperation = packageManager.AddPackageByUriAsync(new Uri(latestRelease.Url),
+                new AddPackageOptions()
+                {
+                    DeferRegistrationWhenPackagesAreInUse = true,
+                    ForceUpdateFromAnyVersion = true,
+                    ForceAppShutdown = quitOnUpdate
+                });
+        }
         asyncOperation.Progress = (info, progressInfo) =>
         {
             NotifyInstallProgress(progressInfo.percentage, latestRelease);
@@ -150,6 +169,24 @@ private void NotifyInstallProgress(uint percentage, FwLiteRelease release)
         eventBus.PublishEvent(new AppUpdateProgressEvent(percentage, release));
     }
 
+    /// <summary>
+    /// The .appinstaller URI this install is associated with, or null if it wasn't installed via an
+    /// .appinstaller file (i.e. it's not on the OS update track and should use the direct-bundle path).
+    /// </summary>
+    private Uri? GetAppInstallerUri()
+    {
+        try
+        {
+            return Windows.ApplicationModel.Package.Current.GetAppInstallerInfo()?.Uri;
+        }
+        catch (Exception e)
+        {
+            //Package.Current throws for unpackaged/portable apps; treat as "not on the track".
+            logger.LogWarning(e, "Unable to read App Installer info; falling back to direct bundle update");
+            return null;
+        }
+    }
+
     public DateTime LastUpdateCheck
     {
         get => preferences.Get(LastUpdateCheckKey, DateTime.MinValue);

backend/LexBoxApi/Controllers/FwLiteReleaseController.cs

@@ -22,10 +22,6 @@ public async Task<ActionResult> DownloadLatest([FromQuery] FwLiteEdition edition
         activity?.AddTag(FwLiteReleaseService.FwLiteEditionTag, edition.ToString());
         if (edition == FwLiteEdition.WindowsAppInstaller)
         {
-            //note this doesn't really work because the github server doesn't return the correct content-type of application/msixbundle
-            //in order for this to work we would need to proxy the request to github
-            //but then we would need to support range requests https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests
-            //which is too complicated for now
             var appInstallerContent = await releaseService.GenerateAppInstaller();
             return File(Encoding.UTF8.GetBytes(appInstallerContent), "application/appinstaller", "FieldWorksLite.appinstaller");
         }

backend/LexBoxApi/Services/FwLiteReleases/FwLiteReleaseService.cs

@@ -120,23 +120,26 @@ public async ValueTask<string> GenerateAppInstaller(CancellationToken token = de
    Version="{version}"
    Uri="{windowsRelease.Url}" />
  <UpdateSettings>
-   <OnLaunch
-     HoursBetweenUpdateChecks="8"
-     ShowPrompt="true"
-     UpdateBlocksActivation="false" />
+   <!-- No OnLaunch: Windows never checks on start, so it can't show an update prompt and doesn't
+        race the in-app updater. Updates are applied silently by the background task (~every 8h). -->
    <ForceUpdateFromAnyVersion>false</ForceUpdateFromAnyVersion>
    <AutomaticBackgroundTask />
  </UpdateSettings>
 </AppInstaller>
 """;
     }
 
-    private static string ConvertVersionToAppInstallerVersion(string version)
+    //public for testing (like ShouldUpdateToRelease): this MUST match the bundle's manifest identity
+    //version exactly (CI stamps that from `date +%Y.%-m.%-d` plus a `.1` revision in the MakeAppx /bv
+    //arg), or the App Installer install fails with an identity mismatch.
+    public static string ConvertVersionToAppInstallerVersion(string version)
     {
-        //version is something like v2025-01-17-a62c709c which should be converted to 2025.1.17.1 always adding .1 on the end and trimming zeros
+        //version is something like v2025-01-17-a62c709c which should be converted to 2025.1.17.1,
+        //always adding .1 on the end. int.Parse drops leading zeros
         return version.Split('-') switch
         {
-            [var year, var month, var day, ..] => $"{year.TrimStart('v')}.{month.TrimStart('0')}.{day.TrimStart('0')}.1",
+            [var year, var month, var day, ..] =>
+                $"{int.Parse(year.TrimStart('v'))}.{int.Parse(month)}.{int.Parse(day)}.1",
             _ => throw new ArgumentException($"Invalid version {version}")
         };
     }

backend/Testing/LexCore/Services/FwLiteReleaseServiceTests.cs

@@ -92,4 +92,14 @@ public void ShouldUpdateToReleaseGivesExpectedResult(string appVersion,
         var actual = FwLiteReleaseService.ShouldUpdateToRelease(appVersion, latestVersion);
         actual.Should().Be(expected, reason);
     }
+
+    [Theory]
+    //must match the bundle identity version CI stamps: `date +%Y.%-m.%-d` (no leading zeros) + ".1"
+    [InlineData("v2025-01-17-a62c709c", "2025.1.17.1")]
+    [InlineData("v2026-07-06-915ca19d", "2026.7.6.1")]
+    [InlineData("v2026-10-30-deadbeef", "2026.10.30.1")]
+    public void ConvertVersionToAppInstallerVersionGivesExpectedResult(string tag, string expected)
+    {
+        FwLiteReleaseService.ConvertVersionToAppInstallerVersion(tag).Should().Be(expected);
+    }
 }