From d71632aa38ba4ad2023a1dfd9f319de6cd804b4f Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Mon, 6 Apr 2015 15:32:22 -0700
Subject: [PATCH 1/2] Check for omitted expressions when checking const and let
 declaration names

---
 src/compiler/checker.ts                       |  4 +-
 .../reference/arrayBindingPattern.js          | 31 +++++++++++++
 .../reference/arrayBindingPattern.types       | 43 +++++++++++++++++++
 tests/cases/compiler/arrayBindingPattern.ts   | 17 ++++++++
 4 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/arrayBindingPattern.js
 create mode 100644 tests/baselines/reference/arrayBindingPattern.types
 create mode 100644 tests/cases/compiler/arrayBindingPattern.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 54d722f53b0..d154bc1c93b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -12596,7 +12596,9 @@ module ts {
             else {
                 let elements = (<BindingPattern>name).elements;
                 for (let element of elements) {
-                    checkGrammarNameInLetOrConstDeclarations(element.name);
+                    if (element.kind !== SyntaxKind.OmittedExpression) {
+                        checkGrammarNameInLetOrConstDeclarations(element.name);
+                    }
                 }
             }
         }
diff --git a/tests/baselines/reference/arrayBindingPattern.js b/tests/baselines/reference/arrayBindingPattern.js
new file mode 100644
index 00000000000..bd1b350fbe4
--- /dev/null
+++ b/tests/baselines/reference/arrayBindingPattern.js
@@ -0,0 +1,31 @@
+//// [arrayBindingPattern.ts]
+
+var results: string[];
+
+{
+    let [, b, , a] = results;
+    let x = {
+        a,
+        b
+    }
+}
+
+
+function f([, a, , b, , , , s, , , ] = results) {
+    a = s[1];
+    b = s[2];
+}
+
+//// [arrayBindingPattern.js]
+var results;
+{
+    let [, b, , a] = results;
+    let x = {
+        a,
+        b
+    };
+}
+function f([, a, , b, , , , s, , ,] = results) {
+    a = s[1];
+    b = s[2];
+}
diff --git a/tests/baselines/reference/arrayBindingPattern.types b/tests/baselines/reference/arrayBindingPattern.types
new file mode 100644
index 00000000000..a157a357fe7
--- /dev/null
+++ b/tests/baselines/reference/arrayBindingPattern.types
@@ -0,0 +1,43 @@
+=== tests/cases/compiler/arrayBindingPattern.ts ===
+
+var results: string[];
+>results : string[]
+
+{
+    let [, b, , a] = results;
+>b : string
+>a : string
+>results : string[]
+
+    let x = {
+>x : { a: string; b: string; }
+>{        a,        b    } : { a: string; b: string; }
+
+        a,
+>a : string
+
+        b
+>b : string
+    }
+}
+
+
+function f([, a, , b, , , , s, , , ] = results) {
+>f : ([, a, , b, , , , s, , , ]?: string[]) => void
+>a : string
+>b : string
+>s : string
+>results : string[]
+
+    a = s[1];
+>a = s[1] : string
+>a : string
+>s[1] : string
+>s : string
+
+    b = s[2];
+>b = s[2] : string
+>b : string
+>s[2] : string
+>s : string
+}
diff --git a/tests/cases/compiler/arrayBindingPattern.ts b/tests/cases/compiler/arrayBindingPattern.ts
new file mode 100644
index 00000000000..61d8c6f7dda
--- /dev/null
+++ b/tests/cases/compiler/arrayBindingPattern.ts
@@ -0,0 +1,17 @@
+// @target: ES6
+
+var results: string[];
+
+{
+    let [, b, , a] = results;
+    let x = {
+        a,
+        b
+    }
+}
+
+
+function f([, a, , b, , , , s, , , ] = results) {
+    a = s[1];
+    b = s[2];
+}
\ No newline at end of file

From 238a33daa0edf54f38a49ce716383cf50de53d60 Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Mon, 6 Apr 2015 16:24:55 -0700
Subject: [PATCH 2/2] Rename test case

---
 ...ingPattern.js => arrayBindingPatternOmittedExpressions.js} | 4 ++--
 ...tern.types => arrayBindingPatternOmittedExpressions.types} | 2 +-
 ...ingPattern.ts => arrayBindingPatternOmittedExpressions.ts} | 0
 3 files changed, 3 insertions(+), 3 deletions(-)
 rename tests/baselines/reference/{arrayBindingPattern.js => arrayBindingPatternOmittedExpressions.js} (75%)
 rename tests/baselines/reference/{arrayBindingPattern.types => arrayBindingPatternOmittedExpressions.types} (83%)
 rename tests/cases/compiler/{arrayBindingPattern.ts => arrayBindingPatternOmittedExpressions.ts} (100%)

diff --git a/tests/baselines/reference/arrayBindingPattern.js b/tests/baselines/reference/arrayBindingPatternOmittedExpressions.js
similarity index 75%
rename from tests/baselines/reference/arrayBindingPattern.js
rename to tests/baselines/reference/arrayBindingPatternOmittedExpressions.js
index bd1b350fbe4..a6f01d7b75c 100644
--- a/tests/baselines/reference/arrayBindingPattern.js
+++ b/tests/baselines/reference/arrayBindingPatternOmittedExpressions.js
@@ -1,4 +1,4 @@
-//// [arrayBindingPattern.ts]
+//// [arrayBindingPatternOmittedExpressions.ts]
 
 var results: string[];
 
@@ -16,7 +16,7 @@ function f([, a, , b, , , , s, , , ] = results) {
     b = s[2];
 }
 
-//// [arrayBindingPattern.js]
+//// [arrayBindingPatternOmittedExpressions.js]
 var results;
 {
     let [, b, , a] = results;
diff --git a/tests/baselines/reference/arrayBindingPattern.types b/tests/baselines/reference/arrayBindingPatternOmittedExpressions.types
similarity index 83%
rename from tests/baselines/reference/arrayBindingPattern.types
rename to tests/baselines/reference/arrayBindingPatternOmittedExpressions.types
index a157a357fe7..ba1ac955b85 100644
--- a/tests/baselines/reference/arrayBindingPattern.types
+++ b/tests/baselines/reference/arrayBindingPatternOmittedExpressions.types
@@ -1,4 +1,4 @@
-=== tests/cases/compiler/arrayBindingPattern.ts ===
+=== tests/cases/compiler/arrayBindingPatternOmittedExpressions.ts ===
 
 var results: string[];
 >results : string[]
diff --git a/tests/cases/compiler/arrayBindingPattern.ts b/tests/cases/compiler/arrayBindingPatternOmittedExpressions.ts
similarity index 100%
rename from tests/cases/compiler/arrayBindingPattern.ts
rename to tests/cases/compiler/arrayBindingPatternOmittedExpressions.ts