From 8dcf8a648995fc761d8298a942c7bd2965b4390e Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Wed, 31 Jan 2018 10:43:14 -0800
Subject: [PATCH] Add semicolon to unused class member list (#21495)

Turns out SemicolonClassElement is a specific kind for semicolons inside
a class. Having one of them with --noUnusedLocals on would crash the
compiler after the assert added in #21013.
---
 src/compiler/checker.ts                             |  1 +
 tests/baselines/reference/unusedSemicolonInClass.js | 13 +++++++++++++
 .../reference/unusedSemicolonInClass.symbols        |  7 +++++++
 .../reference/unusedSemicolonInClass.types          |  7 +++++++
 tests/cases/compiler/unusedSemicolonInClass.ts      |  4 ++++
 5 files changed, 32 insertions(+)
 create mode 100644 tests/baselines/reference/unusedSemicolonInClass.js
 create mode 100644 tests/baselines/reference/unusedSemicolonInClass.symbols
 create mode 100644 tests/baselines/reference/unusedSemicolonInClass.types
 create mode 100644 tests/cases/compiler/unusedSemicolonInClass.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index f0208518c77..07ceaa13563 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -21031,6 +21031,7 @@ namespace ts {
                             }
                             break;
                         case SyntaxKind.IndexSignature:
+                        case SyntaxKind.SemicolonClassElement:
                             // Can't be private
                             break;
                         default:
diff --git a/tests/baselines/reference/unusedSemicolonInClass.js b/tests/baselines/reference/unusedSemicolonInClass.js
new file mode 100644
index 00000000000..c33f799fec4
--- /dev/null
+++ b/tests/baselines/reference/unusedSemicolonInClass.js
@@ -0,0 +1,13 @@
+//// [unusedSemicolonInClass.ts]
+class Unused {
+    ;
+}
+
+
+//// [unusedSemicolonInClass.js]
+var Unused = /** @class */ (function () {
+    function Unused() {
+    }
+    ;
+    return Unused;
+}());
diff --git a/tests/baselines/reference/unusedSemicolonInClass.symbols b/tests/baselines/reference/unusedSemicolonInClass.symbols
new file mode 100644
index 00000000000..0e1832d1f3a
--- /dev/null
+++ b/tests/baselines/reference/unusedSemicolonInClass.symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/unusedSemicolonInClass.ts ===
+class Unused {
+>Unused : Symbol(Unused, Decl(unusedSemicolonInClass.ts, 0, 0))
+
+    ;
+}
+
diff --git a/tests/baselines/reference/unusedSemicolonInClass.types b/tests/baselines/reference/unusedSemicolonInClass.types
new file mode 100644
index 00000000000..118259662f4
--- /dev/null
+++ b/tests/baselines/reference/unusedSemicolonInClass.types
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/unusedSemicolonInClass.ts ===
+class Unused {
+>Unused : Unused
+
+    ;
+}
+
diff --git a/tests/cases/compiler/unusedSemicolonInClass.ts b/tests/cases/compiler/unusedSemicolonInClass.ts
new file mode 100644
index 00000000000..5cd62690ba9
--- /dev/null
+++ b/tests/cases/compiler/unusedSemicolonInClass.ts
@@ -0,0 +1,4 @@
+// @noUnusedLocals: true
+class Unused {
+    ;
+}