From 47385b29e0ea1b14b2db85b6b34540d591adfa0f Mon Sep 17 00:00:00 2001
From: Wesley Wigham <wwigham@gmail.com>
Date: Fri, 27 Apr 2018 15:55:53 -0700
Subject: [PATCH] Actually visit expression node on empty destructuring
 assignment (#23744)

---
 src/compiler/transformers/destructuring.ts    |  2 +-
 ...ructuringExpressionVisitedByTransformer.js |  7 ++++++
 ...ringExpressionVisitedByTransformer.symbols | 15 +++++++++++
 ...turingExpressionVisitedByTransformer.types | 25 +++++++++++++++++++
 ...ructuringExpressionVisitedByTransformer.ts |  2 ++
 5 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.js
 create mode 100644 tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.symbols
 create mode 100644 tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.types
 create mode 100644 tests/cases/compiler/emptyArrayDestructuringExpressionVisitedByTransformer.ts

diff --git a/src/compiler/transformers/destructuring.ts b/src/compiler/transformers/destructuring.ts
index 35101d3be7f..2dd8946e8e2 100644
--- a/src/compiler/transformers/destructuring.ts
+++ b/src/compiler/transformers/destructuring.ts
@@ -46,7 +46,7 @@ namespace ts {
                     value = node.right;
                 }
                 else {
-                    return value;
+                    return visitNode(value, visitor, isExpression);
                 }
             }
         }
diff --git a/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.js b/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.js
new file mode 100644
index 00000000000..5e7e333f7a6
--- /dev/null
+++ b/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.js
@@ -0,0 +1,7 @@
+//// [emptyArrayDestructuringExpressionVisitedByTransformer.ts]
+var a = [] = [1].map(_ => _);
+var b = [1].map(_ => _);
+
+//// [emptyArrayDestructuringExpressionVisitedByTransformer.js]
+var a = [1].map(function (_) { return _; });
+var b = [1].map(function (_) { return _; });
diff --git a/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.symbols b/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.symbols
new file mode 100644
index 00000000000..5694d47c8c8
--- /dev/null
+++ b/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.symbols
@@ -0,0 +1,15 @@
+=== tests/cases/compiler/emptyArrayDestructuringExpressionVisitedByTransformer.ts ===
+var a = [] = [1].map(_ => _);
+>a : Symbol(a, Decl(emptyArrayDestructuringExpressionVisitedByTransformer.ts, 0, 3))
+>[1].map : Symbol(Array.map, Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --))
+>_ : Symbol(_, Decl(emptyArrayDestructuringExpressionVisitedByTransformer.ts, 0, 21))
+>_ : Symbol(_, Decl(emptyArrayDestructuringExpressionVisitedByTransformer.ts, 0, 21))
+
+var b = [1].map(_ => _);
+>b : Symbol(b, Decl(emptyArrayDestructuringExpressionVisitedByTransformer.ts, 1, 3))
+>[1].map : Symbol(Array.map, Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --))
+>_ : Symbol(_, Decl(emptyArrayDestructuringExpressionVisitedByTransformer.ts, 1, 16))
+>_ : Symbol(_, Decl(emptyArrayDestructuringExpressionVisitedByTransformer.ts, 1, 16))
+
diff --git a/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.types b/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.types
new file mode 100644
index 00000000000..450a24a0fa7
--- /dev/null
+++ b/tests/baselines/reference/emptyArrayDestructuringExpressionVisitedByTransformer.types
@@ -0,0 +1,25 @@
+=== tests/cases/compiler/emptyArrayDestructuringExpressionVisitedByTransformer.ts ===
+var a = [] = [1].map(_ => _);
+>a : number[]
+>[] = [1].map(_ => _) : number[]
+>[] : undefined[]
+>[1].map(_ => _) : number[]
+>[1].map : <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]
+>[1] : number[]
+>1 : 1
+>map : <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]
+>_ => _ : (_: number) => number
+>_ : number
+>_ : number
+
+var b = [1].map(_ => _);
+>b : number[]
+>[1].map(_ => _) : number[]
+>[1].map : <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]
+>[1] : number[]
+>1 : 1
+>map : <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]
+>_ => _ : (_: number) => number
+>_ : number
+>_ : number
+
diff --git a/tests/cases/compiler/emptyArrayDestructuringExpressionVisitedByTransformer.ts b/tests/cases/compiler/emptyArrayDestructuringExpressionVisitedByTransformer.ts
new file mode 100644
index 00000000000..01ad2d61122
--- /dev/null
+++ b/tests/cases/compiler/emptyArrayDestructuringExpressionVisitedByTransformer.ts
@@ -0,0 +1,2 @@
+var a = [] = [1].map(_ => _);
+var b = [1].map(_ => _);
\ No newline at end of file