From 431a8e195a7261bdf49f63c214b05771c4e4b250 Mon Sep 17 00:00:00 2001
From: Kiran Challa <kichalla@microsoft.com>
Date: Mon, 19 Mar 2018 15:52:21 -0700
Subject: [PATCH] [Fixes #2144] Incorrect target element of nested tag helper

---
 .../DefaultTagHelperCompletionService.cs      |  7 +-
 .../DefaultTagHelperCompletionServiceTest.cs  | 69 +++++++++++++++++++
 2 files changed, 75 insertions(+), 1 deletion(-)

diff --git a/src/Microsoft.VisualStudio.Editor.Razor/DefaultTagHelperCompletionService.cs b/src/Microsoft.VisualStudio.Editor.Razor/DefaultTagHelperCompletionService.cs
index 7b927f48ad..dc8d55cb03 100644
--- a/src/Microsoft.VisualStudio.Editor.Razor/DefaultTagHelperCompletionService.cs
+++ b/src/Microsoft.VisualStudio.Editor.Razor/DefaultTagHelperCompletionService.cs
@@ -174,6 +174,11 @@ namespace Microsoft.VisualStudio.Editor.Razor
 
                 foreach (var rule in possibleDescriptor.TagMatchingRules)
                 {
+                    if (!TagHelperMatchingConventions.SatisfiesParentTag(completionContext.ContainingTagName, rule))
+                    {
+                        continue;
+                    }
+
                     if (rule.TagName == TagHelperMatchingConventions.ElementCatchAllName)
                     {
                         catchAllDescriptors.Add(possibleDescriptor);
@@ -210,7 +215,7 @@ namespace Microsoft.VisualStudio.Editor.Razor
             {
                 foreach (var completionTagName in elementCompletions.Keys)
                 {
-                    if (elementCompletions[completionTagName].Count > 0 || 
+                    if (elementCompletions[completionTagName].Count > 0 ||
                         !string.IsNullOrEmpty(prefix) && completionTagName.StartsWith(prefix, StringComparison.OrdinalIgnoreCase))
                     {
                         // The current completion either has other TagHelper's associated with it or is prefixed with a non-empty
diff --git a/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultTagHelperCompletionServiceTest.cs b/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultTagHelperCompletionServiceTest.cs
index aca20bcb3d..47fd565bb4 100644
--- a/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultTagHelperCompletionServiceTest.cs
+++ b/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultTagHelperCompletionServiceTest.cs
@@ -838,6 +838,75 @@ namespace Microsoft.VisualStudio.Editor.Razor
             AssertCompletionsAreEquivalent(expectedCompletions, completions);
         }
 
+        [Fact]
+        public void GetElementCompletions_NoContainingParentTag_DoesNotGetCompletionForRuleWithParentTag()
+        {
+            // Arrange
+            var documentDescriptors = new[]
+            {
+                TagHelperDescriptorBuilder.Create("Tag1", "TestAssembly")
+                    .TagMatchingRuleDescriptor(rule => rule.RequireTagName("outer-child-tag"))
+                    .TagMatchingRuleDescriptor(rule => rule.RequireTagName("child-tag").RequireParentTag("parent-tag"))
+                    .Build(),
+                TagHelperDescriptorBuilder.Create("Tag2", "TestAssembly")
+                    .TagMatchingRuleDescriptor(rule => rule.RequireTagName("parent-tag"))
+                    .AllowChildTag("child-tag")
+                    .Build(),
+            };
+            var expectedCompletions = ElementCompletionResult.Create(new Dictionary<string, HashSet<TagHelperDescriptor>>()
+            {
+                ["outer-child-tag"] = new HashSet<TagHelperDescriptor> { documentDescriptors[0] },
+                ["parent-tag"] = new HashSet<TagHelperDescriptor> { documentDescriptors[1] },
+            });
+
+            var completionContext = BuildElementCompletionContext(
+                documentDescriptors,
+                existingCompletions: Enumerable.Empty<string>(),
+                containingTagName: null,
+                containingParentTagName: null);
+            var service = CreateTagHelperCompletionFactsService();
+
+            // Act
+            var completions = service.GetElementCompletions(completionContext);
+
+            // Assert
+            AssertCompletionsAreEquivalent(expectedCompletions, completions);
+        }
+
+        [Fact]
+        public void GetElementCompletions_WithContainingParentTag_GetsCompletionForRuleWithParentTag()
+        {
+            // Arrange
+            var documentDescriptors = new[]
+            {
+                TagHelperDescriptorBuilder.Create("Tag1", "TestAssembly")
+                    .TagMatchingRuleDescriptor(rule => rule.RequireTagName("outer-child-tag"))
+                    .TagMatchingRuleDescriptor(rule => rule.RequireTagName("child-tag").RequireParentTag("parent-tag"))
+                    .Build(),
+                TagHelperDescriptorBuilder.Create("Tag2", "TestAssembly")
+                    .TagMatchingRuleDescriptor(rule => rule.RequireTagName("parent-tag"))
+                    .AllowChildTag("child-tag")
+                    .Build(),
+            };
+            var expectedCompletions = ElementCompletionResult.Create(new Dictionary<string, HashSet<TagHelperDescriptor>>()
+            {
+                ["child-tag"] = new HashSet<TagHelperDescriptor> { documentDescriptors[0] },
+            });
+
+            var completionContext = BuildElementCompletionContext(
+                documentDescriptors,
+                existingCompletions: Enumerable.Empty<string>(),
+                containingTagName: "parent-tag",
+                containingParentTagName: null);
+            var service = CreateTagHelperCompletionFactsService();
+
+            // Act
+            var completions = service.GetElementCompletions(completionContext);
+
+            // Assert
+            AssertCompletionsAreEquivalent(expectedCompletions, completions);
+        }
+
         [Fact]
         public void GetElementCompletions_AllowedChildrenAreIgnoredWhenAtRoot()
         {