Added PowerPoint templates to the Slide Assistant (#1055)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/Tests/Settings/PluginFilePathTests.cs

@@ -0,0 +1,121 @@
+using AIStudio.Settings;
+
+namespace AIStudio.Tests.Settings;
+
+/// <summary>
+/// Checks how a file a configuration plugin names in a setting is found, e.g., the PowerPoint
+/// template it ships for the Slide Assistant.
+/// </summary>
+[TestFixture]
+public sealed class PluginFilePathTests
+{
+    private string pluginDirectory = string.Empty;
+
+    [SetUp]
+    public void CreatePluginDirectory()
+    {
+        this.pluginDirectory = Path.Combine(Path.GetTempPath(), $"plugin-file-path-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(Path.Combine(this.pluginDirectory, "templates"));
+        File.WriteAllBytes(Path.Combine(this.pluginDirectory, "Corporate.pptx"), [1]);
+        File.WriteAllBytes(Path.Combine(this.pluginDirectory, "templates", "Corporate.potx"), [1]);
+    }
+
+    [TearDown]
+    public void DeletePluginDirectory() => Directory.Delete(this.pluginDirectory, true);
+
+    [Test]
+    public void AFileOfThePluginIsFoundByItsRelativePath()
+    {
+        Assert.Multiple(() =>
+        {
+            Assert.That(PluginFilePath.TryResolve("Corporate.pptx", this.pluginDirectory, out var nextToPlugin, out var issue), Is.True, issue);
+            Assert.That(nextToPlugin, Is.EqualTo(Path.Combine(Path.GetFullPath(this.pluginDirectory), "Corporate.pptx")));
+            Assert.That(PluginFilePath.TryResolve("templates/Corporate.potx", this.pluginDirectory, out var inFolder, out issue), Is.True, issue);
+            Assert.That(inFolder, Is.EqualTo(Path.Combine(Path.GetFullPath(this.pluginDirectory), "templates", "Corporate.potx")), "Both kinds of slashes work on every system.");
+        });
+    }
+
+    [Test]
+    public void AnEmptyOrAbsolutePathStaysAsItIs()
+    {
+        var absolutePath = Path.Combine(Path.GetTempPath(), "somewhere", "Corporate.potx");
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(PluginFilePath.TryResolve(string.Empty, this.pluginDirectory, out var empty, out _), Is.True, "An organization may decide on no file at all.");
+            Assert.That(empty, Is.Empty);
+            Assert.That(PluginFilePath.TryResolve(absolutePath, this.pluginDirectory, out var absolute, out _), Is.True, "A file on a network share is the organization's business.");
+            Assert.That(absolute, Is.EqualTo(absolutePath));
+        });
+    }
+
+    [Test]
+    public void APathLeavingThePluginDirectoryIsRejected()
+    {
+        Assert.Multiple(() =>
+        {
+            Assert.That(PluginFilePath.TryResolve("../Corporate.pptx", this.pluginDirectory, out var resolved, out var issue), Is.False);
+            Assert.That(issue, Does.Contain(".."));
+            Assert.That(resolved, Is.Empty);
+            Assert.That(PluginFilePath.TryResolve("templates/../../Corporate.pptx", this.pluginDirectory, out _, out _), Is.False);
+        });
+    }
+
+    [Test]
+    public void AMissingFileIsRejected()
+    {
+        Assert.Multiple(() =>
+        {
+            Assert.That(PluginFilePath.TryResolve("Missing.pptx", this.pluginDirectory, out var resolved, out var issue), Is.False);
+            Assert.That(issue, Does.Contain("does not exist"));
+            Assert.That(resolved, Is.Empty);
+            Assert.That(PluginFilePath.TryResolve("Corporate.pptx", string.Empty, out _, out _), Is.False, "Without the plugin directory, a relative path means nothing.");
+        });
+    }
+
+    [Test]
+    public void APathWhichHasToStayInsideThePluginLeadsToNothingElse()
+    {
+        var absolutePath = Path.Combine(Path.GetTempPath(), "somewhere", "Corporate.potx");
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(PluginFilePath.TryResolveInside("templates\\Corporate.potx", this.pluginDirectory, out var inFolder, out var issue), Is.True, issue);
+            Assert.That(inFolder, Is.EqualTo(Path.Combine(Path.GetFullPath(this.pluginDirectory), "templates", "Corporate.potx")));
+            Assert.That(PluginFilePath.TryResolveInside(absolutePath, this.pluginDirectory, out var absolute, out issue), Is.False, "Where only a file of the plugin will do, an absolute path is no way out.");
+            Assert.That(issue, Does.Contain("outside"));
+            Assert.That(absolute, Is.Empty);
+            Assert.That(PluginFilePath.TryResolveInside(string.Empty, this.pluginDirectory, out _, out _), Is.False, "An empty path names no file.");
+        });
+    }
+
+    [Test]
+    public void AFolderOfThePluginIsFoundByItsRelativePath()
+    {
+        var absolutePath = Path.Combine(Path.GetTempPath(), "somewhere", "Pictures");
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(PluginFilePath.TryResolveDirectory("templates", this.pluginDirectory, out var inPlugin, out var issue), Is.True, issue);
+            Assert.That(inPlugin, Is.EqualTo(Path.Combine(Path.GetFullPath(this.pluginDirectory), "templates")));
+            Assert.That(PluginFilePath.TryResolveDirectory(string.Empty, this.pluginDirectory, out var empty, out _), Is.True, "An organization may decide on no folder at all.");
+            Assert.That(empty, Is.Empty);
+            Assert.That(PluginFilePath.TryResolveDirectory(absolutePath, this.pluginDirectory, out var absolute, out _), Is.True, "A folder on a network share is the organization's business.");
+            Assert.That(absolute, Is.EqualTo(absolutePath));
+        });
+    }
+
+    [Test]
+    public void AFolderFollowsTheRulesOfAFile()
+    {
+        Assert.Multiple(() =>
+        {
+            Assert.That(PluginFilePath.TryResolveDirectory("templates/../..", this.pluginDirectory, out var resolved, out var issue), Is.False);
+            Assert.That(issue, Does.Contain(".."));
+            Assert.That(resolved, Is.Empty);
+            Assert.That(PluginFilePath.TryResolveDirectory("Corporate.pptx", this.pluginDirectory, out _, out issue), Is.False, "A file is no folder.");
+            Assert.That(issue, Does.Contain("does not exist"));
+            Assert.That(PluginFilePath.TryResolve("templates", this.pluginDirectory, out _, out _), Is.False, "A folder is no file.");
+        });
+    }
+}