Merge pull request #297 from hartez/issue296

Jérémie Bertrand · Jérémie Bertrand · commit edce1cecc3c4 · 2016-02-07T10:02:55.000+01:00
Prevent adding of duplicate tags during PreProcess() in RazorSiteEngine
diff --git a/src/Pretzel.Logic/Templating/Razor/RazorSiteEngine.cs b/src/Pretzel.Logic/Templating/Razor/RazorSiteEngine.cs
@@ -27,22 +27,43 @@ public override void Initialize()
         {
         }
 
-        protected override void PreProcess()
+	    private class TagComparer : IEqualityComparer<ITag>
+	    {
+		    public bool Equals(ITag x, ITag y)
+		    {
+			    if (x == null || y == null)
+			    {
+				    return false;
+			    }
+
+			    return x.Name == y.Name;
+		    }
+
+		    public int GetHashCode(ITag obj)
+		    {
+			    return obj.Name.GetHashCode();
+		    }
+	    }
+
+	    protected override void PreProcess()
         {
             includesPath = Path.Combine(Context.SourceFolder, "_includes");
 
             if (Tags != null)
             {
-                _allTags.AddRange(Tags);
+	            var toAdd = Tags.Except(_allTags, new TagComparer()).ToList();
+	            _allTags.AddRange(toAdd);
             }
 
             if (TagFactories != null)
             {
-                _allTags.AddRange(TagFactories.Select(factory =>
-                    {
-                        factory.Initialize(Context);
-                        return factory.CreateTag();
-                    }));
+	            var toAdd = TagFactories.Select(factory =>
+	            {
+		            factory.Initialize(Context);
+		            return factory.CreateTag();
+	            }).Except(_allTags, new TagComparer()).ToList();
+
+                _allTags.AddRange(toAdd);
             }
         }
 
diff --git a/src/Pretzel.Tests/Templating/Razor/RazorEngineTests.cs b/src/Pretzel.Tests/Templating/Razor/RazorEngineTests.cs
@@ -249,6 +249,25 @@ public void PostUrlTag_should_be_used()
             Assert.Equal(expected, FileSystem.File.ReadAllText(@"C:\website\_site\index.html"));
         }
 
+		[Fact]
+        public void Engine_can_process_template_multiple_times()
+        {
+            // arrange
+            const string templateContents = "<html><body>@Raw(Model.Content) @Tag.PostUrl(\"index.cshtml\")</body></html>";
+            const string pageContents = "<h1>Hello</h1>";
+            const string expected = "<html><body><h1>Hello</h1> /index.html</body></html>";
+
+            Subject.TagFactories = new List<TagFactoryBase> { new PostUrlTagFactory() };
+
+            // act
+			// Process contents multiple times (e.g., when a file has changed in taste)
+            ProcessContents(templateContents, pageContents, new Dictionary<string, object>());
+			ProcessContents(templateContents, pageContents, new Dictionary<string, object>());
+
+            // assert
+            Assert.Equal(expected, FileSystem.File.ReadAllText(@"C:\website\_site\index.html"));
+        }
+
         public class CustomTag : DotLiquid.Tag, ITag
         {
             public new string Name { get { return "Custom"; } }
