From dcb763f62435ebb015e7fa405eb067de3254f217 Mon Sep 17 00:00:00 2001
From: Tan Li Hau <tanhauhau@users.noreply.github.com>
Date: Fri, 16 Aug 2019 06:49:50 +0800
Subject: [PATCH] Report error when using generic class in js file (#31723)

* Report error when using generic class in js file

* Replace "ClassDeclaration | ClassExpression" to ClassLikeDeclaration

Co-Authored-By: Klaus Meinhardt <klaus.meinhardt1@gmail.com>

* add noEmit:true
---
 src/compiler/program.ts                                   | 3 ++-
 ...ilationTypeParameterSyntaxOfClassExpression.errors.txt | 8 ++++++++
 ...ompilationTypeParameterSyntaxOfClassExpression.symbols | 5 +++++
 ...eCompilationTypeParameterSyntaxOfClassExpression.types | 5 +++++
 ...FileCompilationTypeParameterSyntaxOfClassExpression.ts | 4 ++++
 5 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.errors.txt
 create mode 100644 tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.symbols
 create mode 100644 tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.types
 create mode 100644 tests/cases/compiler/jsFileCompilationTypeParameterSyntaxOfClassExpression.ts

diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index c3fdad71e11..76c92ad74bb 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -1833,6 +1833,7 @@ namespace ts {
 
                     switch (parent.kind) {
                         case SyntaxKind.ClassDeclaration:
+                        case SyntaxKind.ClassExpression:
                         case SyntaxKind.MethodDeclaration:
                         case SyntaxKind.MethodSignature:
                         case SyntaxKind.Constructor:
@@ -1842,7 +1843,7 @@ namespace ts {
                         case SyntaxKind.FunctionDeclaration:
                         case SyntaxKind.ArrowFunction:
                             // Check type parameters
-                            if (nodes === (<ClassDeclaration | FunctionLikeDeclaration>parent).typeParameters) {
+                            if (nodes === (<ClassLikeDeclaration | FunctionLikeDeclaration>parent).typeParameters) {
                                 diagnostics.push(createDiagnosticForNodeArray(nodes, Diagnostics.type_parameter_declarations_can_only_be_used_in_a_ts_file));
                                 return;
                             }
diff --git a/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.errors.txt b/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.errors.txt
new file mode 100644
index 00000000000..61bf225dddc
--- /dev/null
+++ b/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.errors.txt
@@ -0,0 +1,8 @@
+tests/cases/compiler/a.js(1,19): error TS8004: 'type parameter declarations' can only be used in a .ts file.
+
+
+==== tests/cases/compiler/a.js (1 errors) ====
+    const Bar = class<T> {};
+                      ~
+!!! error TS8004: 'type parameter declarations' can only be used in a .ts file.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.symbols b/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.symbols
new file mode 100644
index 00000000000..f3aa9cd5926
--- /dev/null
+++ b/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.symbols
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/a.js ===
+const Bar = class<T> {};
+>Bar : Symbol(Bar, Decl(a.js, 0, 5))
+>T : Symbol(T, Decl(a.js, 0, 18))
+
diff --git a/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.types b/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.types
new file mode 100644
index 00000000000..5538564ec86
--- /dev/null
+++ b/tests/baselines/reference/jsFileCompilationTypeParameterSyntaxOfClassExpression.types
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/a.js ===
+const Bar = class<T> {};
+>Bar : typeof Bar
+>class<T> {} : typeof Bar
+
diff --git a/tests/cases/compiler/jsFileCompilationTypeParameterSyntaxOfClassExpression.ts b/tests/cases/compiler/jsFileCompilationTypeParameterSyntaxOfClassExpression.ts
new file mode 100644
index 00000000000..81b07637422
--- /dev/null
+++ b/tests/cases/compiler/jsFileCompilationTypeParameterSyntaxOfClassExpression.ts
@@ -0,0 +1,4 @@
+// @allowJs: true
+// @noEmit: true
+// @filename: a.js
+const Bar = class<T> {};