Add test for dead links in Views

BTCPayServer.Tests/UnitTest1.cs

@@ -73,6 +73,49 @@ namespace BTCPayServer.Tests
             Logs.LogProvider = new XUnitLogProvider(helper);
         }
 
+        [Fact]
+        [Trait("Fast", "Fast")]
+        public async Task CheckNoDeadLink()
+        {
+            var views = Path.Combine(LanguageService.TryGetSolutionDirectoryInfo().FullName, "BTCPayServer", "Views");
+            var viewFiles = Directory.EnumerateFiles(views, "*.cshtml", SearchOption.AllDirectories).ToArray();
+            Assert.NotEmpty(viewFiles);
+            Regex regex = new Regex("href=\"(http.*?)\"");
+            var httpClient = new HttpClient();
+            List<Task> checkLinks = new List<Task>();
+            foreach (var file in viewFiles)
+            {
+                checkLinks.Add(CheckLinks(regex, httpClient, file));
+            }
+            await Task.WhenAll(checkLinks);
+        }
+
+        private static async Task CheckLinks(Regex regex, HttpClient httpClient, string file)
+        {
+            List<Task> checkLinks = new List<Task>();
+            var text = await File.ReadAllTextAsync(file);
+            foreach (var match in regex.Matches(text).OfType<Match>())
+            {
+                checkLinks.Add(AssertLinkNotDead(httpClient, match, file));
+            }
+            await Task.WhenAll(checkLinks);
+        }
+
+        private static async Task AssertLinkNotDead(HttpClient httpClient, Match match, string file)
+        {
+            var url = match.Groups[1].Value;
+            try
+            {
+                Assert.Equal(HttpStatusCode.OK, (await httpClient.GetAsync(url)).StatusCode);
+                Logs.Tester.LogInformation($"OK: {url} ({file})");
+            }
+            catch
+            {
+                Logs.Tester.LogInformation($"FAILED: {url} ({file})");
+                throw;
+            }
+        }
+
         [Fact]
         [Trait("Fast", "Fast")]
         public void CanHandleUriValidation()

BTCPayServer/Views/Home/Home.cshtml

@@ -114,7 +114,7 @@
             <a href="https://slack.btcpayserver.org/" target="_blank">
                 <img src="~/img/slack.png" height="100" />
             </a>
-            <p><a href="http://slack.forkbitpay.ninja/" target="_blank">On Slack</a></p>
+            <p><a href="https://slack.btcpayserver.org/" target="_blank">On Slack</a></p>
         </div>
         <div class="col-lg-3 mr-auto text-center">
             <a href="https://twitter.com/BtcpayServer" target="_blank">