Merge pull request #4598 from Microsoft/destructuringInitializers

Improved checking of destructuring with literal initializers

tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts

@@ -2,8 +2,8 @@ function f0() {
     var [] = [1, "hello"];
     var [x] = [1, "hello"];
     var [x, y] = [1, "hello"];
-    var [x, y, z] = [1, "hello"];  // Error
-    var [,, z] = [0, 1, 2];
+    var [x, y, z] = [1, "hello"];
+    var [,, x] = [0, 1, 2];
     var x: number;
     var y: string;
 }
@@ -19,14 +19,14 @@ function f1() {
 }
 
 function f2() {
-    var { } = { x: 5, y: "hello" };
-    var { x } = { x: 5, y: "hello" };
-    var { y } = { x: 5, y: "hello" };
+    var { } = { x: 5, y: "hello" };       // Error, no x and y in target
+    var { x } = { x: 5, y: "hello" };     // Error, no y in target
+    var { y } = { x: 5, y: "hello" };     // Error, no x in target
     var { x, y } = { x: 5, y: "hello" };
     var x: number;
     var y: string;
-    var { x: a } = { x: 5, y: "hello" };
-    var { y: b } = { x: 5, y: "hello" };
+    var { x: a } = { x: 5, y: "hello" };  // Error, no y in target
+    var { y: b } = { x: 5, y: "hello" };  // Error, no x in target
     var { x: a, y: b } = { x: 5, y: "hello" };
     var a: number;
     var b: string;

tests/cases/conformance/es6/destructuring/destructuringWithLiteralInitializers.ts

@@ -0,0 +1,65 @@
+// (arg: { x: any, y: any }) => void
+function f1({ x, y }) { }
+f1({ x: 1, y: 1 });
+
+// (arg: { x: any, y?: number }) => void
+function f2({ x, y = 0 }) { }
+f2({ x: 1 });
+f2({ x: 1, y: 1 });
+
+// (arg: { x?: number, y?: number }) => void
+function f3({ x = 0, y = 0 }) { }
+f3({});
+f3({ x: 1 });
+f3({ y: 1 });
+f3({ x: 1, y: 1 });
+
+// (arg?: { x: number, y: number }) => void
+function f4({ x, y } = { x: 0, y: 0 }) { }
+f4();
+f4({ x: 1, y: 1 });
+
+// (arg?: { x: number, y?: number }) => void
+function f5({ x, y = 0 } = { x: 0 }) { }
+f5();
+f5({ x: 1 });
+f5({ x: 1, y: 1 });
+
+// (arg?: { x?: number, y?: number }) => void
+function f6({ x = 0, y = 0 } = {}) { }
+f6();
+f6({});
+f6({ x: 1 });
+f6({ y: 1 });
+f6({ x: 1, y: 1 });
+
+// (arg?: { a: { x?: number, y?: number } }) => void
+function f7({ a: { x = 0, y = 0 } } = { a: {} }) { }
+f7();
+f7({ a: {} });
+f7({ a: { x: 1 } });
+f7({ a: { y: 1 } });
+f7({ a: { x: 1, y: 1 } });
+
+// (arg: [any, any]) => void
+function g1([x, y]) { }
+g1([1, 1]);
+
+// (arg: [number, number]) => void
+function g2([x = 0, y = 0]) { }
+g2([1, 1]);
+
+// (arg?: [number, number]) => void
+function g3([x, y] = [0, 0]) { }
+g3();
+g3([1, 1]);
+
+// (arg?: [number, number]) => void
+function g4([x, y = 0] = [0]) { }
+g4();
+g4([1, 1]);
+
+// (arg?: [number, number]) => void
+function g5([x = 0, y = 0] = []) { }
+g5();
+g5([1, 1]);

tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts

@@ -0,0 +1,33 @@
+// Missing properties
+function f1() {
+    var { x, y } = {};
+    var { x = 1, y } = {};
+    var { x, y = 1 } = {};
+    var { x = 1, y = 1 } = {};
+}
+
+// Missing properties
+function f2() {
+    var x: number, y: number;
+    ({ x, y } = {});
+    ({ x: x = 1, y } = {});
+    ({ x, y: y = 1 } = {});
+    ({ x: x = 1, y: y = 1 } = {});
+}
+
+// Excess properties
+function f3() {
+    var { } = { x: 0, y: 0 };
+    var { x } = { x: 0, y: 0 };
+    var { y } = { x: 0, y: 0 };
+    var { x, y } = { x: 0, y: 0 };
+}
+
+// Excess properties
+function f4() {
+    var x: number, y: number;
+    ({ } = { x: 0, y: 0 });
+    ({ x } = { x: 0, y: 0 });
+    ({ y } = { x: 0, y: 0 });
+    ({ x, y } = { x: 0, y: 0 });
+}