From 00d37268e8fd1e52fd90f1616d8a21802dd83b0a Mon Sep 17 00:00:00 2001
From: Andrew Casey <andrew.casey@microsoft.com>
Date: Fri, 23 Aug 2019 12:55:10 -0700
Subject: [PATCH] Make triple-slash comment classification more restrictive

It was overly permissive and ended up making a mess of C#-style
comments:

`/// <summary>Text</summary>`

Now it checks the element name.  Attribute names remain unchecked.
---
 src/services/classifier.ts                           | 12 ++++++++----
 .../syntacticClassificationsTripleSlash17.ts         |  7 +++++++
 .../syntacticClassificationsTripleSlash18.ts         |  7 +++++++
 .../syntacticClassificationsTripleSlash4.ts          |  3 +--
 4 files changed, 23 insertions(+), 6 deletions(-)
 create mode 100644 tests/cases/fourslash/syntacticClassificationsTripleSlash17.ts
 create mode 100644 tests/cases/fourslash/syntacticClassificationsTripleSlash18.ts

diff --git a/src/services/classifier.ts b/src/services/classifier.ts
index 1e1309a2eac..334417ef549 100644
--- a/src/services/classifier.ts
+++ b/src/services/classifier.ts
@@ -771,6 +771,14 @@ namespace ts {
                 return false;
             }
 
+            // Limiting classification to exactly the elements and attributes
+            // defined in `ts.commentPragmas` would be excessive, but we can avoid
+            // some obvious false positives (e.g. in XML-like doc comments) by
+            // checking the element name.
+            if (!match[3] || !(commentPragmas as any)[match[3]]) {
+                return false;
+            }
+
             let pos = start;
 
             pushCommentRange(pos, match[1].length); // ///
@@ -779,10 +787,6 @@ namespace ts {
             pushClassification(pos, match[2].length, ClassificationType.punctuation); // <
             pos += match[2].length;
 
-            if (!match[3]) {
-                return true;
-            }
-
             pushClassification(pos, match[3].length, ClassificationType.jsxSelfClosingTagName); // element name
             pos += match[3].length;
 
diff --git a/tests/cases/fourslash/syntacticClassificationsTripleSlash17.ts b/tests/cases/fourslash/syntacticClassificationsTripleSlash17.ts
new file mode 100644
index 00000000000..b95cdd6b6c0
--- /dev/null
+++ b/tests/cases/fourslash/syntacticClassificationsTripleSlash17.ts
@@ -0,0 +1,7 @@
+/// <reference path="fourslash.ts"/>
+
+//// /// <summary>Text</summary>
+
+var c = classification;
+verify.syntacticClassificationsAre(
+    c.comment("/// <summary>Text</summary>"));
\ No newline at end of file
diff --git a/tests/cases/fourslash/syntacticClassificationsTripleSlash18.ts b/tests/cases/fourslash/syntacticClassificationsTripleSlash18.ts
new file mode 100644
index 00000000000..148b17f6e45
--- /dev/null
+++ b/tests/cases/fourslash/syntacticClassificationsTripleSlash18.ts
@@ -0,0 +1,7 @@
+/// <reference path="fourslash.ts"/>
+
+//// /// <reference>Text</reference>
+
+var c = classification;
+verify.syntacticClassificationsAre(
+    c.comment("/// <reference>Text</reference>"));
\ No newline at end of file
diff --git a/tests/cases/fourslash/syntacticClassificationsTripleSlash4.ts b/tests/cases/fourslash/syntacticClassificationsTripleSlash4.ts
index e656c811377..d407bcee503 100644
--- a/tests/cases/fourslash/syntacticClassificationsTripleSlash4.ts
+++ b/tests/cases/fourslash/syntacticClassificationsTripleSlash4.ts
@@ -4,5 +4,4 @@
 
 var c = classification;
 verify.syntacticClassificationsAre(
-    c.comment("/// "),
-    c.punctuation("<"));
\ No newline at end of file
+    c.comment("/// <")); // Don't classify until we recognize the element name
\ No newline at end of file