Established test for TopicViewLocationExpander with topics

The `TopicViewLocationExpander` supports looking for views based on `Topic.ContentType` and an optional view (which can be specified via a number of locations, though we'll use the query string for the purpose of these tests). It evaluates views established as part of a previous commit (1160903). Each fallback location is given a unique view name so that we don't need to worry about competing views. Each view contains the path to the view so we can confirm the exact view expected was returned.

Author: JeremyCaney

OnTopic.AspNetCore.Mvc.IntegrationTests/TopicViewLocationExpanderTest.cs

@@ -38,5 +38,46 @@ public TopicViewLocationExpanderTest() {
       _factory = new WebApplicationFactory<Startup>();
     }
 
+    /*==========================================================================================================================
+    | TEST: EXPAND VIEW LOCATIONS: VIEWS
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Evaluates multiple views to ensure they fallback to the appropriate locations as defined in <see cref="
+    ///   TopicViewLocationExpander.ViewLocations"/> and <see cref="TopicViewLocationExpander.AreaViewLocations"/>.
+    /// </summary>
+    [TestMethod]
+    [DataRow(                   "AreaContentTypeView",          "ContentType/AreaContentTypeView.cshtml")]
+    [DataRow(                   "AreaContentTypeSharedView",    "ContentType/Shared/AreaContentTypeSharedView.cshtml")]
+    [DataRow(                   "AreaContentTypesView",         "ContentTypes/ContentType.AreaContentTypesView.cshtml")]
+    [DataRow(                   "AreaContentTypesSharedView",   "ContentTypes/Shared/AreaContentTypesSharedView.cshtml")]
+    [DataRow(                   "AreaContentTypesFallbackView", "ContentTypes/AreaContentTypesFallbackView.cshtml")]
+    [DataRow(                   "AreaSharedView",               "Shared/AreaSharedView.cshtml")]
+    [DataRow(                   "ContentTypeView",              "ContentType/ContentTypeView.cshtml")]
+    [DataRow(                   "ContentTypeSharedView",        "ContentType/Shared/ContentTypeSharedView.cshtml")]
+    [DataRow(                   "ContentTypesView",             "ContentTypes/ContentType.ContentTypesView.cshtml")]
+    [DataRow(                   "ContentTypesSharedView",       "ContentTypes/Shared/ContentTypesSharedView.cshtml")]
+    [DataRow(                   "ContentTypesFallbackView",     "ContentTypes/ContentTypesFallbackView.cshtml")]
+    [DataRow(                   "SharedView",                   "Shared/SharedView.cshtml")]
+    public async Task ExpandViewLocations_Views(string viewName, string viewLocation) {
+
+      if (viewName is not null && viewName.StartsWith("Area", StringComparison.OrdinalIgnoreCase)) {
+        viewLocation = $"~/Areas/Area/Views/{viewLocation}";
+      }
+      else {
+        viewLocation = $"~/Views/{viewLocation}";
+      }
+
+      var client                = _factory.CreateClient();
+      var uri                   = new Uri($"/Area/?View={viewName}", UriKind.Relative);
+      var response              = await client.GetAsync(uri).ConfigureAwait(false);
+      var content               = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
+
+      response.EnsureSuccessStatusCode();
+
+      Assert.AreEqual<string?>("text/html; charset=utf-8", response.Content.Headers.ContentType?.ToString());
+      Assert.AreEqual<string?>(viewLocation, content);
+
+    }
+
   }
 }