Unit testing extract

.github/copilot-instructions.md

@@ -16,7 +16,9 @@ dotnet msbuild "Simple QR Code Maker.slnx" /restore /p:Configuration=Release /p:
 ```
 
 - Visual Studio 2022 with the Windows App SDK workload and MSIX tooling is required; see `.vsconfig`.
-- There is no automated test project in this repository, so there is no single-test command to run.
+- Run headless tests with `.\scripts\Test.ps1 -Platform ARM64` (or `x64` on x64 hosts); add `-Coverage` for TRX and Cobertura reports.
+- Run a single suite with `dotnet test --project "tests\Simple QR Code Maker.Core.Tests\Simple QR Code Maker.Core.Tests.csproj" -p:Platform=ARM64`. Use MTP filtering options shown by that project's `--help` to select tests.
+- Core tests are portable; Windows tests require Windows and run without launching the app. Filesystem integration tests use isolated temporary directories.
 - There is no dedicated lint command configured in the repository.
 
 ## UI automation testing
@@ -25,7 +27,7 @@ Always ask the user and wait for explicit approval before running UI automation
 
 ## High-level architecture
 
-- The solution has two projects: `Simple QR Code Maker` is the WinUI 3 app, and `Simple QR Code Maker.Core` contains shared infrastructure such as `FileService`.
+- The app references portable `Simple QR Code Maker.Core` (builders, parsing, workflow/print policies, infrastructure) and headless `Simple QR Code Maker.Windows` (rendering, persistence, Windows models). Each library has an MSTest/MTP project under `tests`.
 - `App.xaml.cs` is the composition root. It builds a `Microsoft.Extensions.Hosting` host, registers services/view models/views, and routes startup through `IActivationService`.
 - Activation is split between `DefaultActivationHandler` and `ShareTargetActivationHandler`. Shared images route into `DecodingViewModel`; shared text and URIs route into `MainViewModel`.
 - `ShellPage` hosts navigation. `PageService` maps view-model keys to pages, and `NavigationService` performs frame navigation and forwards `INavigationAware` lifecycle calls.

.github/workflows/build.yml

@@ -1,38 +1,65 @@
 name: Build
 
 on:
-  # push:
-  #   branches:
-  #     - main
-  #     - dev
-  # pull_request:
-  #   branches:
-  #     - main
-  #     - dev
+  push:
+    branches: [main, dev]
+  pull_request:
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 concurrency:
-  group: ${{ github.workflow }}
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs:
+  test:
+    name: Tests (${{ matrix.os }}, ${{ matrix.platform }})
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - os: ubuntu-latest
+          platform: x64
+        - os: windows-latest
+          platform: x64
+        - os: windows-11-arm
+          platform: ARM64
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v6
+    - uses: actions/setup-dotnet@v5
+      with:
+        dotnet-version: '10.0.x'
+    - name: Run headless tests with coverage
+      shell: pwsh
+      run: .\scripts\Test.ps1 -Platform ${{ matrix.platform }} -Coverage
+    - name: Upload results and coverage
+      if: always()
+      uses: actions/upload-artifact@v4
+      with:
+        name: test-results-${{ matrix.os }}-${{ matrix.platform }}
+        path: TestResults
+        if-no-files-found: warn
+
   build:
+    name: Packaged app (x64)
     runs-on: windows-latest
-
     steps:
     - name: Checkout code
       uses: actions/checkout@v6
-
-    - name: Setup .NET
+    - name: Setup .NET 10 runtime and SDK
       uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: '9.0.x'
-
+        dotnet-version: '10.0.x'
+    # Existing app sources use preview collection-expression arguments.
+    - name: Setup preview compiler
+      uses: actions/setup-dotnet@v5
+      with:
+        dotnet-version: '11.0.x'
+        dotnet-quality: preview
     - name: Setup MSBuild
       uses: microsoft/setup-msbuild@v2
-
-    - name: Restore
-      run: msbuild "Simple QR Code Maker.sln" /t:Restore /p:Configuration=Release /p:Platform=x64
-
     - name: Build
-      run: msbuild "Simple QR Code Maker.sln" /p:Configuration=Release /p:Platform=x64
+      run: dotnet msbuild "Simple QR Code Maker.slnx" /restore /p:Configuration=Release /p:Platform=x64 /nologo

CLAUDE.md

@@ -26,9 +26,9 @@ dotnet msbuild "Simple QR Code Maker.slnx" -p:Configuration=Release -p:Platform=
 
 Visual Studio 2022 with the Windows App SDK workload and MSIX packaging tools is required. See `.vsconfig` for the exact required components.
 
-## No Automated Tests
+## Automated Tests
 
-There are no unit or integration test projects. Testing is done manually using MSIX packages in `AppPackages/`.
+Run `.\scripts\Test.ps1 -Platform ARM64` (use `x64` on x64 hosts), adding `-Coverage` for TRX and Cobertura reports in `TestResults`. `-Suite Core` selects portable tests; `-Suite Windows` selects headless Windows tests. Tests use MSTest with Microsoft.Testing.Platform, not VSTest. No app activation, real app data, Excel installation, or desktop interaction is needed.
 
 ## UI Automation Testing
 
@@ -41,7 +41,9 @@ The app follows **MVVM + Dependency Injection** using `CommunityToolkit.Mvvm` an
 ### Solution Structure
 
 - **`Simple QR Code Maker/`** — Main WinUI 3 app project
-- **`Simple QR Code Maker.Core/`** — Shared library (currently just `FileService` for JSON I/O)
+- **`Simple QR Code Maker.Core/`** — Portable builders, parsers, workflow/print policies, and JSON/file infrastructure
+- **`Simple QR Code Maker.Windows/`** — Headless Windows rendering, persistence, and models
+- **`tests/`** — MSTest/MTP projects exercising the actual production libraries
 
 ### App Entry & DI
 

README.md

@@ -137,6 +137,29 @@ On the reading side, v2 can decode codes from files, folders, drag-and-drop, the
 - Export settings, brands, and history to a ZIP backup.
 - Import settings, brands, and history from a ZIP backup.
 
+## Development and testing
+
+The app targets .NET 10 and uses WinUI 3/MSIX. Build it with Visual Studio's Windows App SDK/MSIX tooling and `dotnet msbuild "Simple QR Code Maker.slnx" /restore /p:Configuration=Debug /p:Platform=ARM64 /nologo` (or `x64`). Existing app sources use preview collection-expression arguments, so the app build currently needs the .NET 11 preview SDK as well as the .NET 10 runtime.
+
+The production logic lives in two libraries: portable `Simple QR Code Maker.Core`, and headless Windows-specific `Simple QR Code Maker.Windows`. Both are referenced by the app and by MSTest/Microsoft.Testing.Platform test projects. Tests do not launch the app or touch its settings.
+
+```powershell
+# Run both headless suites on Windows; Core only on other platforms.
+.\scripts\Test.ps1 -Platform ARM64
+
+# Run one suite, including coverage and TRX results in TestResults.
+.\scripts\Test.ps1 -Platform ARM64 -Suite Core -Coverage
+
+# Direct runner invocation (use x64 on x64 hosts).
+dotnet test --project "tests\Simple QR Code Maker.Windows.Tests\Simple QR Code Maker.Windows.Tests.csproj" -p:Platform=ARM64
+```
+
+The test projects require .NET 10. Use `-Suite Core` on Linux/macOS. Real filesystem checks are marked `Integration`, operate only in unique temporary directories, and clean up after themselves. Native image processing is exercised on matching x64/ARM64 hosts. CI runs portable tests on Linux and both suites on Windows x64/ARM64, and publishes results and coverage even when a suite fails.
+
+Coverage runs enforce the measured production-library floors in `tests\thresholds.json`. Keep these ratcheting upward; generated code is excluded, but entire helper/service classes are not. Core requires 95% line and 90% branch coverage; Windows requires 85% line and 80% branch coverage.
+
+Keep tests deterministic: use synthetic data, fixed timestamps/cultures where relevant, controllable tasks instead of sleeps, and structural image/PDF assertions instead of whole-file snapshots. Regression tests should cover success, invalid input, boundaries, failures, and legacy compatibility. XAML bindings, actual pickers, clipboard, camera, Windows AI availability, Excel COM integration, and printing remain platform/UI checks; **running anything that launches or interacts with the app requires explicit user approval**.
+
 ---
 
 Made with ❤️ in Milwaukee by Joe Finney.

Simple QR Code Maker.Core/Contracts/Services/IFileService.cs

@@ -2,9 +2,9 @@
 
 public interface IFileService
 {
-    T Read<T>(string folderPath, string fileName);
+    T? Read<T>(string folderPath, string fileName);
 
     void Save<T>(string folderPath, string fileName, T content);
 
-    void Delete(string folderPath, string fileName);
+    void Delete(string folderPath, string? fileName);
 }

Simple QR Code Maker/Enums.cs → Simple QR Code Maker.Core/Enums.cs

@@ -1,4 +1,4 @@
-namespace Simple_QR_Code_Maker;
+namespace Simple_QR_Code_Maker;
 
 public enum FileKind
 {

Simple QR Code Maker.Core/Helpers/AsyncBatchProcessor.cs

@@ -0,0 +1,43 @@
+namespace Simple_QR_Code_Maker.Helpers;
+
+public static class AsyncBatchProcessor
+{
+    public static async Task RunAsync<T>(
+        IReadOnlyList<T> items,
+        int maxConcurrency,
+        Func<T, Task> process,
+        Action<int>? updateProgress = null,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentOutOfRangeException.ThrowIfNegativeOrZero(maxConcurrency);
+        ArgumentNullException.ThrowIfNull(process);
+        using SemaphoreSlim semaphore = new(maxConcurrency, maxConcurrency);
+        int completed = 0;
+        await Task.WhenAll(items.Select(ProcessAsync));
+
+        async Task ProcessAsync(T item)
+        {
+            await semaphore.WaitAsync(cancellationToken);
+            try
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+                await process(item);
+            }
+            finally
+            {
+                try
+                {
+                    if (updateProgress is not null)
+                    {
+                        lock (semaphore)
+                            updateProgress(++completed);
+                    }
+                }
+                finally
+                {
+                    semaphore.Release();
+                }
+            }
+        }
+    }
+}

Simple QR Code Maker/Helpers/CsvParser.cs → Simple QR Code Maker.Core/Helpers/CsvParser.cs

@@ -13,16 +13,15 @@ public static class CsvParser
     /// </summary>
     public static List<List<string>> Parse(string csv, char delimiter = ',')
     {
+        ValidateDelimiter(delimiter);
         List<List<string>> rows = [];
         if (string.IsNullOrEmpty(csv))
             return rows;
 
-        // Normalise line endings to LF only so we can treat \n as the row separator.
-        csv = csv.Replace("\r\n", "\n").Replace('\r', '\n');
-
         List<string> currentRow = [];
         StringBuilder currentField = new();
         bool inQuotes = false;
+        bool fieldStarted = false;
         int i = 0;
 
         while (i < csv.Length)
@@ -57,6 +56,7 @@ public static List<List<string>> Parse(string csv, char delimiter = ',')
                 if (c == '"')
                 {
                     inQuotes = true;
+                    fieldStarted = true;
                     i++;
                 }
                 else if (c == delimiter)
@@ -65,13 +65,16 @@ public static List<List<string>> Parse(string csv, char delimiter = ',')
                     currentField.Clear();
                     i++;
                 }
-                else if (c == '\n')
+                else if (c is '\r' or '\n')
                 {
                     currentRow.Add(currentField.ToString());
                     currentField.Clear();
                     rows.Add(currentRow);
                     currentRow = [];
+                    fieldStarted = false;
                     i++;
+                    if (c == '\r' && i < csv.Length && csv[i] == '\n')
+                        i++;
                 }
                 else
                 {
@@ -82,17 +85,19 @@ public static List<List<string>> Parse(string csv, char delimiter = ',')
         }
 
         // Flush the last field and row (file may not end with a newline).
-        currentRow.Add(currentField.ToString());
-        // Only add the last row if it is non-empty (avoids a phantom blank row for
-        // files that do end with a newline).
-        if (currentRow.Count > 1 || (currentRow.Count == 1 && currentRow[0].Length > 0))
+        if (currentRow.Count > 0 || currentField.Length > 0 || fieldStarted)
+        {
+            currentRow.Add(currentField.ToString());
             rows.Add(currentRow);
+        }
 
         return rows;
     }
 
     public static string Serialize(IEnumerable<IReadOnlyList<string>> rows, char delimiter = ',')
     {
+        ArgumentNullException.ThrowIfNull(rows);
+        ValidateDelimiter(delimiter);
         StringBuilder builder = new();
         bool isFirstRow = true;
 
@@ -106,7 +111,9 @@ public static string Serialize(IEnumerable<IReadOnlyList<string>> rows, char del
                 if (index > 0)
                     builder.Append(delimiter);
 
-                builder.Append(EscapeField(row[index], delimiter));
+                builder.Append(row.Count == 1 && row[index].Length == 0
+                    ? "\"\""
+                    : EscapeField(row[index], delimiter));
             }
 
             isFirstRow = false;
@@ -115,6 +122,12 @@ public static string Serialize(IEnumerable<IReadOnlyList<string>> rows, char del
         return builder.ToString();
     }
 
+    private static void ValidateDelimiter(char delimiter)
+    {
+        if (delimiter is '"' or '\r' or '\n')
+            throw new ArgumentOutOfRangeException(nameof(delimiter), "A delimiter cannot be a quote or newline.");
+    }
+
     private static string EscapeField(string field, char delimiter)
     {
         bool requiresQuotes = field.Contains(delimiter)

Simple QR Code Maker.Core/Helpers/DelimitedSpreadsheetHelper.cs

@@ -0,0 +1,43 @@
+using Simple_QR_Code_Maker.Models;
+
+namespace Simple_QR_Code_Maker.Helpers;
+
+public static class DelimitedSpreadsheetHelper
+{
+    public static async Task<SpreadsheetReadResult> ReadAsync(string filePath, char delimiter)
+    {
+        string contents = await File.ReadAllTextAsync(filePath);
+        List<List<string>> rows = CsvParser.Parse(contents, delimiter);
+        return new SpreadsheetReadResult
+        {
+            Rows = [.. rows.Select((row, index) => new SpreadsheetSourceRow
+            {
+                SourceRowIndex = index,
+                Cells = [.. row],
+            })],
+        };
+    }
+
+    public static async Task WriteGeneratedIdsAsync(string filePath, char delimiter, SpreadsheetIdWriteRequest request)
+    {
+        string contents = await File.ReadAllTextAsync(filePath);
+        List<List<string>> rows = CsvParser.Parse(contents, delimiter);
+        SpreadsheetImportPolicy.ApplyGeneratedIds(rows, request);
+        string updatedContents = CsvParser.Serialize(rows, delimiter);
+        string fullPath = Path.GetFullPath(filePath);
+        string directory = Path.GetDirectoryName(fullPath)
+            ?? throw new InvalidOperationException("Unable to determine the spreadsheet file directory.");
+        string tempFilePath = Path.Combine(directory, $"{Path.GetFileName(fullPath)}.{Guid.NewGuid():N}.tmp");
+
+        try
+        {
+            await File.WriteAllTextAsync(tempFilePath, updatedContents);
+            File.Replace(tempFilePath, fullPath, destinationBackupFileName: null, ignoreMetadataErrors: true);
+        }
+        finally
+        {
+            if (File.Exists(tempFilePath))
+                File.Delete(tempFilePath);
+        }
+    }
+}

Simple QR Code Maker/Helpers/EmailBuilderHelper.cs → Simple QR Code Maker.Core/Helpers/EmailBuilderHelper.cs

@@ -56,7 +56,10 @@ public static string Serialize(EmailBuilderState state)
 
         StringBuilder builder = new();
         builder.Append(MailtoPrefix);
-        builder.Append(state.To.Trim());
+        builder.Append(Uri.EscapeDataString(state.To.Trim())
+            .Replace("%40", "@")
+            .Replace("%2C", ",")
+            .Replace("%3B", ";"));
 
         List<string> queryParts = [];
 

Simple QR Code Maker.Core/Helpers/Json.cs

@@ -10,15 +10,15 @@ public static class Json
         TypeInfoResolver = new DefaultJsonTypeInfoResolver()
     };
 
-    public static async Task<T> ToObjectAsync<T>(string value)
+    public static async Task<T?> ToObjectAsync<T>(string value)
     {
-        return await Task.Run<T>(() =>
+        return await Task.Run<T?>(() =>
         {
             return JsonSerializer.Deserialize<T>(value, _options);
         });
     }
 
-    public static async Task<string> StringifyAsync(object value)
+    public static async Task<string> StringifyAsync(object? value)
     {
         return await Task.Run<string>(() =>
         {