Add automated external link validation test for WinUI Gallery with dynamic discovery

tests/WinUIGallery.UnitTests/UnitTests.cs

@@ -12,7 +12,11 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting.AppContainer;
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
+using System.Net.Http;
+using System.Text.Json;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
 using Windows.Foundation;
@@ -184,6 +188,274 @@ private void ExecuteOnUIThread(Action action)
         }
     }
 
+    [TestMethod]
+    public async Task TestExternalLinksValidity()
+    {
+        // Dynamically discover all external links from the project
+        var externalLinks = await GetAllExternalLinksAsync();
+
+        Assert.IsTrue(externalLinks.Count > 0, "No external links found in project");
+
+        using var httpClient = new HttpClient();
+        httpClient.Timeout = TimeSpan.FromSeconds(30); // Set reasonable timeout
+
+        // Add user agent to avoid some servers blocking the request
+        httpClient.DefaultRequestHeaders.Add("User-Agent", "WinUI-Gallery-LinkValidator/1.0");
+
+        var failedLinks = new List<string>();
+        var checkedCount = 0;
+
+        foreach (var link in externalLinks)
+        {
+            try
+            {
+                using var response = await httpClient.GetAsync(link);
+                checkedCount++;
+
+                // Consider 2xx and 3xx status codes as success
+                // Also accept some 4xx codes that might be normal for redirect services
+                if (!response.IsSuccessStatusCode && 
+                    (int)response.StatusCode >= 400 && 
+                    response.StatusCode != System.Net.HttpStatusCode.TooManyRequests)
+                {
+                    failedLinks.Add($"{link} - Status: {response.StatusCode}");
+                }
+            }
+            catch (HttpRequestException ex) when (ex.Message.Contains("Name or service not known") || 
+                                                 ex.Message.Contains("temporarily unavailable"))
+            {
+                // Skip DNS resolution failures in test environments
+                checkedCount++;
+                continue;
+            }
+            catch (HttpRequestException ex)
+            {
+                failedLinks.Add($"{link} - HttpRequestException: {ex.Message}");
+                checkedCount++;
+            }
+            catch (TaskCanceledException ex)
+            {
+                failedLinks.Add($"{link} - Timeout: {ex.Message}");
+                checkedCount++;
+            }
+            catch (Exception ex)
+            {
+                failedLinks.Add($"{link} - Exception: {ex.Message}");
+                checkedCount++;
+            }
+
+            // Add small delay to be respectful to servers
+            await Task.Delay(100);
+        }
+
+        // Assert that we checked a reasonable number of links and no critical failures occurred
+        Assert.IsTrue(checkedCount > 0, "No links were checked");
+
+        // If more than 50% of links fail, it's likely a test environment issue
+        if (failedLinks.Count > externalLinks.Count / 2)
+        {
+            Assert.Inconclusive($"More than 50% of links failed ({failedLinks.Count}/{externalLinks.Count}), " +
+                              "which may indicate test environment network restrictions. " +
+                              $"Checked {checkedCount} links. Found {externalLinks.Count} total external links.");
+        }
+
+        // Assert that no links failed with actual HTTP errors (not network issues)
+        var httpErrorFailures = failedLinks.Where(f => f.Contains("Status:") && 
+                                                      !f.Contains("TooManyRequests")).ToList();
+
+        if (httpErrorFailures.Any())
+        {
+            var failureMessage = $"The following external links returned HTTP errors:\n{string.Join("\n", httpErrorFailures)}";
+            Assert.Fail(failureMessage);
+        }
+    }
+
+    /// <summary>
+    /// Dynamically discovers all external links from XAML files and ControlInfoData.json
+    /// </summary>
+    private async Task<List<string>> GetAllExternalLinksAsync()
+    {
+        var allLinks = new HashSet<string>();
+
+        // Get the project root directory (assuming test is running in bin/Debug/net8.0-windows10.0.19041.0 or similar)
+        var testDirectory = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
+        var projectRoot = GetProjectRootDirectory(testDirectory);
+
+        if (projectRoot == null)
+        {
+            throw new DirectoryNotFoundException("Could not find project root directory");
+        }
+
+        // Discover links from XAML files
+        var xamlLinks = await GetExternalLinksFromXamlFilesAsync(projectRoot);
+        foreach (var link in xamlLinks)
+        {
+            allLinks.Add(link);
+        }
+
+        // Discover links from ControlInfoData.json
+        var jsonLinks = await GetExternalLinksFromControlInfoDataAsync(projectRoot);
+        foreach (var link in jsonLinks)
+        {
+            allLinks.Add(link);
+        }
+
+        return allLinks.ToList();
+    }
+
+    /// <summary>
+    /// Finds the project root directory by looking for the .sln file
+    /// </summary>
+    private string GetProjectRootDirectory(string startPath)
+    {
+        var directory = new DirectoryInfo(startPath);
+
+        while (directory != null)
+        {
+            if (directory.GetFiles("*.sln").Any())
+            {
+                return directory.FullName;
+            }
+            directory = directory.Parent;
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Extracts external links from NavigateUri attributes in XAML files
+    /// </summary>
+    private async Task<List<string>> GetExternalLinksFromXamlFilesAsync(string projectRoot)
+    {
+        var links = new List<string>();
+
+        // Find all XAML files in the WinUIGallery directory
+        var winUIGalleryPath = Path.Combine(projectRoot, "WinUIGallery");
+        if (!Directory.Exists(winUIGalleryPath))
+        {
+            return links;
+        }
+
+        var xamlFiles = Directory.GetFiles(winUIGalleryPath, "*.xaml", SearchOption.AllDirectories);
+
+        // Regex to find NavigateUri attributes with URLs
+        var navigateUriRegex = new Regex(@"NavigateUri\s*=\s*[""']([^""']+)[""']", RegexOptions.IgnoreCase);
+
+        foreach (var xamlFile in xamlFiles)
+        {
+            try
+            {
+                var content = await File.ReadAllTextAsync(xamlFile);
+                var matches = navigateUriRegex.Matches(content);
+
+                foreach (Match match in matches)
+                {
+                    var uri = match.Groups[1].Value;
+                    if (IsExternalLink(uri))
+                    {
+                        links.Add(uri);
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                // Log but don't fail for individual file reading issues
+                System.Diagnostics.Debug.WriteLine($"Failed to read XAML file {xamlFile}: {ex.Message}");
+            }
+        }
+
+        return links;
+    }
+
+    /// <summary>
+    /// Extracts external links from the ControlInfoData.json file
+    /// </summary>
+    private async Task<List<string>> GetExternalLinksFromControlInfoDataAsync(string projectRoot)
+    {
+        var links = new List<string>();
+
+        var controlInfoDataPath = Path.Combine(projectRoot, "WinUIGallery", "Samples", "Data", "ControlInfoData.json");
+
+        if (!File.Exists(controlInfoDataPath))
+        {
+            return links;
+        }
+
+        try
+        {
+            var jsonContent = await File.ReadAllTextAsync(controlInfoDataPath);
+            using var document = JsonDocument.Parse(jsonContent);
+
+            if (document.RootElement.TryGetProperty("Groups", out var groups))
+            {
+                foreach (var group in groups.EnumerateArray())
+                {
+                    if (group.TryGetProperty("Items", out var items))
+                    {
+                        foreach (var item in items.EnumerateArray())
+                        {
+                            if (item.TryGetProperty("Docs", out var docs))
+                            {
+                                foreach (var doc in docs.EnumerateArray())
+                                {
+                                    if (doc.TryGetProperty("Uri", out var uri))
+                                    {
+                                        var uriValue = uri.GetString();
+                                        if (!string.IsNullOrEmpty(uriValue) && IsExternalLink(uriValue))
+                                        {
+                                            links.Add(uriValue);
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            System.Diagnostics.Debug.WriteLine($"Failed to parse ControlInfoData.json: {ex.Message}");
+        }
+
+        return links;
+    }
+
+    /// <summary>
+    /// Determines if a URI is an external link that should be validated
+    /// </summary>
+    private static bool IsExternalLink(string uri)
+    {
+        if (string.IsNullOrWhiteSpace(uri))
+            return false;
+
+        // Consider HTTP/HTTPS links as external
+        if (uri.StartsWith("http://", StringComparison.OrdinalIgnoreCase) ||
+            uri.StartsWith("https://", StringComparison.OrdinalIgnoreCase))
+        {
+            return true;
+        }
+
+        // Consider ms-windows-store:// links as external
+        if (uri.StartsWith("ms-windows-store://", StringComparison.OrdinalIgnoreCase))
+        {
+            return true;
+        }
+
+        // Exclude internal/local URIs
+        if (uri.StartsWith("ms-appx://", StringComparison.OrdinalIgnoreCase) ||
+            uri.StartsWith("ms-appdata://", StringComparison.OrdinalIgnoreCase) ||
+            uri.StartsWith("ms-resource://", StringComparison.OrdinalIgnoreCase) ||
+            uri.StartsWith("/", StringComparison.OrdinalIgnoreCase) ||
+            uri.StartsWith("./", StringComparison.OrdinalIgnoreCase) ||
+            uri.StartsWith("../", StringComparison.OrdinalIgnoreCase))
+        {
+            return false;
+        }
+
+        return false;
+    }
+
     [TestCleanup]
     public void Cleanup()
     {