Properly emit nested destructuring in rest elements (fixes #2587)

microsoft · Apr 14, 2015 · 2b83dfb · 2b83dfb
1 parent 051aa39
commit 2b83dfb
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Showing 14 changed files with 63 additions and 49 deletions.
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
@@ -2558,14 +2558,24 @@ var __param = this.__param || function(index, decorator) { return function (targ
                     return node;
                 }
 
-                function createPropertyAccessForDestructuringProperty(object: Expression, propName: Identifier): Expression {
+                function createPropertyAccessForDestructuringProperty(object: Expression, propName: Identifier | LiteralExpression): Expression {
                     if (propName.kind !== SyntaxKind.Identifier) {
                         return createElementAccessExpression(object, propName);
                     }
 
                     return createPropertyAccessExpression(object, propName);
                 }
 
+                function createSliceCall(value: Expression, sliceIndex: number): CallExpression {
+                    let call = <CallExpression>createSynthesizedNode(SyntaxKind.CallExpression);
+                    let sliceIdentifier = <Identifier>createSynthesizedNode(SyntaxKind.Identifier);
+                    sliceIdentifier.text = "slice";
+                    call.expression = createPropertyAccessExpression(value, sliceIdentifier);
+                    call.arguments = <NodeArray<LiteralExpression>>createSynthesizedNodeArray();
+                    call.arguments[0] = createNumericLiteral(sliceIndex);
+                    return call;
+                }
+
                 function emitObjectLiteralAssignment(target: ObjectLiteralExpression, value: Expression) {
                     let properties = target.properties;
                     if (properties.length !== 1) {
@@ -2576,7 +2586,7 @@ var __param = this.__param || function(index, decorator) { return function (targ
                     for (let p of properties) {
                         if (p.kind === SyntaxKind.PropertyAssignment || p.kind === SyntaxKind.ShorthandPropertyAssignment) {
                             // TODO(andersh): Computed property support
-                            let propName = <Identifier>((<PropertyAssignment>p).name);
+                            let propName = <Identifier | LiteralExpression>((<PropertyAssignment>p).name);
                             emitDestructuringAssignment((<PropertyAssignment>p).initializer || propName, createPropertyAccessForDestructuringProperty(value, propName));
                         }
                     }
@@ -2596,9 +2606,7 @@ var __param = this.__param || function(index, decorator) { return function (targ
                                 emitDestructuringAssignment(e, createElementAccessExpression(value, createNumericLiteral(i)));
                             }
                             else if (i === elements.length - 1) {
-                                value = ensureIdentifier(value);
-                                emitAssignment(<Identifier>(<SpreadElementExpression>e).expression, value);
-                                write(".slice(" + i + ")");
+                                emitDestructuringAssignment((<SpreadElementExpression>e).expression, createSliceCall(value, i));
                             }
                         }
                     }
@@ -2670,9 +2678,7 @@ var __param = this.__param || function(index, decorator) { return function (targ
                                     emitBindingElement(element, createElementAccessExpression(value, createNumericLiteral(i)));
                                 }
                                 else if (i === elements.length - 1) {
-                                    value = ensureIdentifier(value);
-                                    emitAssignment(<Identifier>element.name, value);
-                                    write(".slice(" + i + ")");
+                                    emitBindingElement(element, createSliceCall(value, i));
                                 }
                             }
                         }

diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
@@ -1379,6 +1379,13 @@ module ts {
         return node;
     }
 
+    export function createSynthesizedNodeArray(): NodeArray<any> {
+        var array = <NodeArray<any>>[];
+        array.pos = -1;
+        array.end = -1;
+        return array;
+    }
+
     /* @internal */
     export function createDiagnosticCollection(): DiagnosticCollection {
         let nonFileDiagnostics: Diagnostic[] = [];

diff --git a/tests/baselines/reference/declarationEmitDestructuringArrayPattern4.js b/tests/baselines/reference/declarationEmitDestructuringArrayPattern4.js
@@ -10,14 +10,14 @@ var [x18, y18, ...a12] = [1, "hello", true];
 var [x19, y19, z19, ...a13] = [1, "hello", true];
 
 //// [declarationEmitDestructuringArrayPattern4.js]
-var _a = [1, 2, 3], a5 = _a.slice(0);
-var _b = [1, 2, 3], x14 = _b[0], a6 = _b.slice(1);
-var _c = [1, 2, 3], x15 = _c[0], y15 = _c[1], a7 = _c.slice(2);
-var _d = [1, 2, 3], x16 = _d[0], y16 = _d[1], z16 = _d[2], a8 = _d.slice(3);
-var _e = [1, "hello", true], a9 = _e.slice(0);
-var _f = [1, "hello", true], x17 = _f[0], a10 = _f.slice(1);
-var _g = [1, "hello", true], x18 = _g[0], y18 = _g[1], a12 = _g.slice(2);
-var _h = [1, "hello", true], x19 = _h[0], y19 = _h[1], z19 = _h[2], a13 = _h.slice(3);
+var a5 = ([1, 2, 3]).slice(0);
+var _a = [1, 2, 3], x14 = _a[0], a6 = _a.slice(1);
+var _b = [1, 2, 3], x15 = _b[0], y15 = _b[1], a7 = _b.slice(2);
+var _c = [1, 2, 3], x16 = _c[0], y16 = _c[1], z16 = _c[2], a8 = _c.slice(3);
+var a9 = ([1, "hello", true]).slice(0);
+var _d = [1, "hello", true], x17 = _d[0], a10 = _d.slice(1);
+var _e = [1, "hello", true], x18 = _e[0], y18 = _e[1], a12 = _e.slice(2);
+var _f = [1, "hello", true], x19 = _f[0], y19 = _f[1], z19 = _f[2], a13 = _f.slice(3);
 
 
 //// [declarationEmitDestructuringArrayPattern4.d.ts]

diff --git a/tests/baselines/reference/declarationsAndAssignments.js b/tests/baselines/reference/declarationsAndAssignments.js
@@ -321,28 +321,28 @@ function f20() {
     var x;
     var y;
     var z;
-    var _a = [1, 2, 3], a = _a.slice(0);
-    var _b = [1, 2, 3], x = _b[0], a = _b.slice(1);
-    var _c = [1, 2, 3], x = _c[0], y = _c[1], a = _c.slice(2);
-    var _d = [1, 2, 3], x = _d[0], y = _d[1], z = _d[2], a = _d.slice(3);
-    _e = [1, 2, 3], a = _e.slice(0);
-    _f = [1, 2, 3], x = _f[0], a = _f.slice(1);
-    _g = [1, 2, 3], x = _g[0], y = _g[1], a = _g.slice(2);
-    _h = [1, 2, 3], x = _h[0], y = _h[1], z = _h[2], a = _h.slice(3);
-    var _e, _f, _g, _h;
+    var a = ([1, 2, 3]).slice(0);
+    var _a = [1, 2, 3], x = _a[0], a = _a.slice(1);
+    var _b = [1, 2, 3], x = _b[0], y = _b[1], a = _b.slice(2);
+    var _c = [1, 2, 3], x = _c[0], y = _c[1], z = _c[2], a = _c.slice(3);
+    a = ([1, 2, 3]).slice(0);
+    _d = [1, 2, 3], x = _d[0], a = _d.slice(1);
+    _e = [1, 2, 3], x = _e[0], y = _e[1], a = _e.slice(2);
+    _f = [1, 2, 3], x = _f[0], y = _f[1], z = _f[2], a = _f.slice(3);
+    var _d, _e, _f;
 }
 function f21() {
     var a;
     var x;
     var y;
     var z;
-    var _a = [1, "hello", true], a = _a.slice(0);
-    var _b = [1, "hello", true], x = _b[0], a = _b.slice(1);
-    var _c = [1, "hello", true], x = _c[0], y = _c[1], a = _c.slice(2);
-    var _d = [1, "hello", true], x = _d[0], y = _d[1], z = _d[2], a = _d.slice(3);
-    _e = [1, "hello", true], a = _e.slice(0);
-    _f = [1, "hello", true], x = _f[0], a = _f.slice(1);
-    _g = [1, "hello", true], x = _g[0], y = _g[1], a = _g.slice(2);
-    _h = [1, "hello", true], x = _h[0], y = _h[1], z = _h[2], a = _h.slice(3);
-    var _e, _f, _g, _h;
+    var a = ([1, "hello", true]).slice(0);
+    var _a = [1, "hello", true], x = _a[0], a = _a.slice(1);
+    var _b = [1, "hello", true], x = _b[0], y = _b[1], a = _b.slice(2);
+    var _c = [1, "hello", true], x = _c[0], y = _c[1], z = _c[2], a = _c.slice(3);
+    a = ([1, "hello", true]).slice(0);
+    _d = [1, "hello", true], x = _d[0], a = _d.slice(1);
+    _e = [1, "hello", true], x = _e[0], y = _e[1], a = _e.slice(2);
+    _f = [1, "hello", true], x = _f[0], y = _f[1], z = _f[2], a = _f.slice(3);
+    var _d, _e, _f;
 }
diff --git a/tests/baselines/reference/nonIterableRestElement1.js b/tests/baselines/reference/nonIterableRestElement1.js
@@ -4,5 +4,4 @@ var c = {};
 
 //// [nonIterableRestElement1.js]
 var c = {};
-_a = ["", 0], c = _a.slice(0);
-var _a;
+c = (["", 0]).slice(0);
diff --git a/tests/baselines/reference/nonIterableRestElement3.js b/tests/baselines/reference/nonIterableRestElement3.js
@@ -4,5 +4,4 @@ var c = { bogus: 0 };
 
 //// [nonIterableRestElement3.js]
 var c = { bogus: 0 };
-_a = ["", 0], c = _a.slice(0);
-var _a;
+c = (["", 0]).slice(0);
diff --git a/tests/baselines/reference/restElementWithAssignmentPattern3.js b/tests/baselines/reference/restElementWithAssignmentPattern3.js
@@ -6,4 +6,5 @@ var tuple: [string, number] = ["", 1];
 //// [restElementWithAssignmentPattern3.js]
 var a, b;
 var tuple = ["", 1];
-[a, b = 0] = tuple.slice(0);
+_a = tuple.slice(0), a = _a[0], _b = _a[1], b = _b === void 0 ? 0 : _b;
+var _a, _b;
diff --git a/tests/baselines/reference/restElementWithAssignmentPattern4.js b/tests/baselines/reference/restElementWithAssignmentPattern4.js
@@ -6,4 +6,5 @@ var tuple: [string, number] = ["", 1];
 //// [restElementWithAssignmentPattern4.js]
 var a, b;
 var tuple = ["", 1];
-{ 0: a = "", b: b } = tuple.slice(0);
+_a = tuple.slice(0), _b = _a[0], a = _b === void 0 ? "" : _b, b = _a.b;
+var _a, _b;
diff --git a/tests/baselines/reference/restElementWithAssignmentPattern5.js b/tests/baselines/reference/restElementWithAssignmentPattern5.js
@@ -4,5 +4,5 @@ var s: string, s2: string;
 
 //// [restElementWithAssignmentPattern5.js]
 var s, s2;
-_a = ["", ""], [s, s2] = _a.slice(0);
+_a = (["", ""]).slice(0), s = _a[0], s2 = _a[1];
 var _a;
diff --git a/tests/baselines/reference/restElementWithBindingPattern.js b/tests/baselines/reference/restElementWithBindingPattern.js
@@ -2,4 +2,4 @@
 var [...[a, b]] = [0, 1];
 
 //// [restElementWithBindingPattern.js]
-var _a = [0, 1], [a, b] = _a.slice(0);
+var _a = ([0, 1]).slice(0), a = _a[0], b = _a[1];
diff --git a/tests/baselines/reference/restElementWithBindingPattern2.js b/tests/baselines/reference/restElementWithBindingPattern2.js
@@ -2,4 +2,4 @@
 var [...{0: a, b }] = [0, 1];
 
 //// [restElementWithBindingPattern2.js]
-var _a = [0, 1], { 0: a, b } = _a.slice(0);
+var _a = ([0, 1]).slice(0), a = _a[0], b = _a.b;
diff --git a/tests/baselines/reference/restElementWithInitializer1.js b/tests/baselines/reference/restElementWithInitializer1.js
@@ -5,4 +5,4 @@ var [...x = a] = a;  // Error, rest element cannot have initializer
 
 //// [restElementWithInitializer1.js]
 var a;
-var x = a.slice(0); // Error, rest element cannot have initializer
+var _a = a.slice(0), x = _a === void 0 ? a : _a; // Error, rest element cannot have initializer
diff --git a/tests/baselines/reference/restElementWithInitializer2.js b/tests/baselines/reference/restElementWithInitializer2.js
@@ -7,4 +7,5 @@ var x: number[];
 //// [restElementWithInitializer2.js]
 var a;
 var x;
-x = a = a.slice(0); // Error, rest element cannot have initializer
+_a = a.slice(0), x = _a === void 0 ? a : _a; // Error, rest element cannot have initializer
+var _a;
diff --git a/tests/baselines/reference/restElementWithNullInitializer.js b/tests/baselines/reference/restElementWithNullInitializer.js
@@ -14,14 +14,14 @@ function foo4([...r] = []) {
 
 //// [restElementWithNullInitializer.js]
 function foo1(_a) {
-    var _b = _a === void 0 ? null : _a, r = _b.slice(0);
+    var r = (_a === void 0 ? null : _a).slice(0);
 }
 function foo2(_a) {
-    var _b = _a === void 0 ? undefined : _a, r = _b.slice(0);
+    var r = (_a === void 0 ? undefined : _a).slice(0);
 }
 function foo3(_a) {
-    var _b = _a === void 0 ? {} : _a, r = _b.slice(0);
+    var r = (_a === void 0 ? {} : _a).slice(0);
 }
 function foo4(_a) {
-    var _b = _a === void 0 ? [] : _a, r = _b.slice(0);
+    var r = (_a === void 0 ? [] : _a).slice(0);
 }