From f284821088a74991f44bad75566a019fee866a8e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8E=8B=E6=96=87=E7=92=90?= <kingwenlu@gmail.com>
Date: Wed, 25 Jul 2018 18:47:48 +0800
Subject: [PATCH] fix compiler crash

---
 src/compiler/transformers/ts.ts                 |  2 +-
 tests/baselines/reference/constEnum4.js         | 13 +++++++++++++
 tests/baselines/reference/constEnum4.symbols    | 13 +++++++++++++
 tests/baselines/reference/constEnum4.types      | 17 +++++++++++++++++
 .../cases/conformance/constEnums/constEnum4.ts  |  6 ++++++
 5 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/constEnum4.js
 create mode 100644 tests/baselines/reference/constEnum4.symbols
 create mode 100644 tests/baselines/reference/constEnum4.types
 create mode 100644 tests/cases/conformance/constEnums/constEnum4.ts

diff --git a/src/compiler/transformers/ts.ts b/src/compiler/transformers/ts.ts
index bf4ae5ce7d33e..6d4875cd5a575 100644
--- a/src/compiler/transformers/ts.ts
+++ b/src/compiler/transformers/ts.ts
@@ -2621,7 +2621,7 @@ namespace ts {
          */
         function visitEnumDeclaration(node: EnumDeclaration): VisitResult<Statement> {
             if (!shouldEmitEnumDeclaration(node)) {
-                return undefined;
+                return createNotEmittedStatement(node);
             }
 
             const statements: Statement[] = [];
diff --git a/tests/baselines/reference/constEnum4.js b/tests/baselines/reference/constEnum4.js
new file mode 100644
index 0000000000000..dc7c4b0e593ec
--- /dev/null
+++ b/tests/baselines/reference/constEnum4.js
@@ -0,0 +1,13 @@
+//// [constEnum4.ts]
+if (1)
+    const enum A { }
+else if (2)
+    const enum B { }
+else
+    const enum C { }
+
+
+//// [constEnum4.js]
+if (1)
+else if (2)
+else
diff --git a/tests/baselines/reference/constEnum4.symbols b/tests/baselines/reference/constEnum4.symbols
new file mode 100644
index 0000000000000..0098e85c130ea
--- /dev/null
+++ b/tests/baselines/reference/constEnum4.symbols
@@ -0,0 +1,13 @@
+=== tests/cases/conformance/constEnums/constEnum4.ts ===
+if (1)
+    const enum A { }
+>A : Symbol(A, Decl(constEnum4.ts, 0, 6))
+
+else if (2)
+    const enum B { }
+>B : Symbol(B, Decl(constEnum4.ts, 2, 11))
+
+else
+    const enum C { }
+>C : Symbol(C, Decl(constEnum4.ts, 4, 4))
+
diff --git a/tests/baselines/reference/constEnum4.types b/tests/baselines/reference/constEnum4.types
new file mode 100644
index 0000000000000..a35e9f898bf8e
--- /dev/null
+++ b/tests/baselines/reference/constEnum4.types
@@ -0,0 +1,17 @@
+=== tests/cases/conformance/constEnums/constEnum4.ts ===
+if (1)
+>1 : 1
+
+    const enum A { }
+>A : A
+
+else if (2)
+>2 : 2
+
+    const enum B { }
+>B : B
+
+else
+    const enum C { }
+>C : C
+
diff --git a/tests/cases/conformance/constEnums/constEnum4.ts b/tests/cases/conformance/constEnums/constEnum4.ts
new file mode 100644
index 0000000000000..c6dc5840c4682
--- /dev/null
+++ b/tests/cases/conformance/constEnums/constEnum4.ts
@@ -0,0 +1,6 @@
+if (1)
+    const enum A { }
+else if (2)
+    const enum B { }
+else
+    const enum C { }