From 6b5330f3432bc35dfb19963bfdc3cc317e495fdd Mon Sep 17 00:00:00 2001
From: Vadi Taslim <vadz77@hotmail.com>
Date: Fri, 24 Mar 2017 12:39:36 +0800
Subject: [PATCH] Bug fix for issue #14696, things changed are; - Empty class
 type will now throw an error, - Trailing comma in class type will also throw
 an error, - Added tests for empty class type parameter, - Updated tests for
 class type parameters with trailing comma

This behavior is consistently following function or method like when its type parameter is either empty or has trailing comma.
---
 src/compiler/checker.ts                                |  7 ++++++-
 .../reference/classWithEmptyTypeParameter.errors.txt   |  8 ++++++++
 .../baselines/reference/classWithEmptyTypeParameter.js | 10 ++++++++++
 .../typeParameterListWithTrailingComma1.errors.txt     |  8 ++++++++
 tests/cases/compiler/classWithEmptyTypeParameter.ts    |  2 ++
 5 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/classWithEmptyTypeParameter.errors.txt
 create mode 100644 tests/baselines/reference/classWithEmptyTypeParameter.js
 create mode 100644 tests/baselines/reference/typeParameterListWithTrailingComma1.errors.txt
 create mode 100644 tests/cases/compiler/classWithEmptyTypeParameter.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 70cbda14f6d..448a15e513b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -19559,7 +19559,7 @@ namespace ts {
         }
 
         function checkClassLikeDeclaration(node: ClassLikeDeclaration) {
-            checkGrammarClassDeclarationHeritageClauses(node);
+            checkGrammarClassLikeDeclaration(node);
             checkDecorators(node);
             if (node.name) {
                 checkTypeNameIsReserved(node.name, Diagnostics.Class_name_cannot_be_0);
@@ -22520,6 +22520,11 @@ namespace ts {
                 checkGrammarParameterList(node.parameters) || checkGrammarArrowFunction(node, file);
         }
 
+        function checkGrammarClassLikeDeclaration(node: ClassLikeDeclaration): boolean {
+            const file = getSourceFileOfNode(node);
+            return checkGrammarClassDeclarationHeritageClauses(node) || checkGrammarTypeParameterList(node.typeParameters, file);
+        }
+
         function checkGrammarArrowFunction(node: FunctionLikeDeclaration, file: SourceFile): boolean {
             if (node.kind === SyntaxKind.ArrowFunction) {
                 const arrowFunction = <ArrowFunction>node;
diff --git a/tests/baselines/reference/classWithEmptyTypeParameter.errors.txt b/tests/baselines/reference/classWithEmptyTypeParameter.errors.txt
new file mode 100644
index 00000000000..8114bbd7ba0
--- /dev/null
+++ b/tests/baselines/reference/classWithEmptyTypeParameter.errors.txt
@@ -0,0 +1,8 @@
+tests/cases/compiler/classWithEmptyTypeParameter.ts(1,8): error TS1098: Type parameter list cannot be empty.
+
+
+==== tests/cases/compiler/classWithEmptyTypeParameter.ts (1 errors) ====
+    class C<> {
+           ~~
+!!! error TS1098: Type parameter list cannot be empty.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/classWithEmptyTypeParameter.js b/tests/baselines/reference/classWithEmptyTypeParameter.js
new file mode 100644
index 00000000000..c25ace495b4
--- /dev/null
+++ b/tests/baselines/reference/classWithEmptyTypeParameter.js
@@ -0,0 +1,10 @@
+//// [classWithEmptyTypeParameter.ts]
+class C<> {
+}
+
+//// [classWithEmptyTypeParameter.js]
+var C = (function () {
+    function C() {
+    }
+    return C;
+}());
diff --git a/tests/baselines/reference/typeParameterListWithTrailingComma1.errors.txt b/tests/baselines/reference/typeParameterListWithTrailingComma1.errors.txt
new file mode 100644
index 00000000000..ac20e826969
--- /dev/null
+++ b/tests/baselines/reference/typeParameterListWithTrailingComma1.errors.txt
@@ -0,0 +1,8 @@
+tests/cases/compiler/typeParameterListWithTrailingComma1.ts(1,10): error TS1009: Trailing comma not allowed.
+
+
+==== tests/cases/compiler/typeParameterListWithTrailingComma1.ts (1 errors) ====
+    class C<T,> {
+             ~
+!!! error TS1009: Trailing comma not allowed.
+    }
\ No newline at end of file
diff --git a/tests/cases/compiler/classWithEmptyTypeParameter.ts b/tests/cases/compiler/classWithEmptyTypeParameter.ts
new file mode 100644
index 00000000000..42541c8e467
--- /dev/null
+++ b/tests/cases/compiler/classWithEmptyTypeParameter.ts
@@ -0,0 +1,2 @@
+class C<> {
+}
\ No newline at end of file