Codegen: Do not subtract 0 in arguments to rest array loop

src/compiler/transformers/es2015.ts

@@ -1306,7 +1306,9 @@ namespace ts {
                             createAssignment(
                                 createElementAccess(
                                     expressionName,
-                                    createSubtract(temp, createLiteral(restIndex))
+                                    restIndex === 0
+                                        ? temp
+                                        : createSubtract(temp, createLiteral(restIndex))
                                 ),
                                 createElementAccess(createIdentifier("arguments"), temp)
                             ),

tests/baselines/reference/accessorWithRestParam.js

@@ -13,7 +13,7 @@ var C = (function () {
         set: function () {
             var v = [];
             for (var _i = 0; _i < arguments.length; _i++) {
-                v[_i - 0] = arguments[_i];
+                v[_i] = arguments[_i];
             }
         },
         enumerable: true,
@@ -23,7 +23,7 @@ var C = (function () {
         set: function () {
             var v2 = [];
             for (var _i = 0; _i < arguments.length; _i++) {
-                v2[_i - 0] = arguments[_i];
+                v2[_i] = arguments[_i];
             }
         },
         enumerable: true,

tests/baselines/reference/assignmentCompatWithCallSignaturesWithRestParameters.js

@@ -52,14 +52,14 @@ a = function () { return 1; }; // ok, same number of required params
 a = function () {
     var args = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        args[_i - 0] = arguments[_i];
+        args[_i] = arguments[_i];
     }
     return 1;
 }; // ok, same number of required params
 a = function () {
     var args = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        args[_i - 0] = arguments[_i];
+        args[_i] = arguments[_i];
     }
     return 1;
 }; // error, type mismatch
@@ -72,7 +72,7 @@ a2 = function () { return 1; }; // ok, fewer required params
 a2 = function () {
     var args = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        args[_i - 0] = arguments[_i];
+        args[_i] = arguments[_i];
     }
     return 1;
 }; // ok, fewer required params

tests/baselines/reference/baseTypeAfterDerivedType.js

@@ -23,7 +23,7 @@ var Derived2 = (function () {
     Derived2.prototype.method = function () {
         var args = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            args[_i - 0] = arguments[_i];
+            args[_i] = arguments[_i];
         }
     };
     return Derived2;

tests/baselines/reference/checkSuperCallBeforeThisAccessing5.js

@@ -17,7 +17,7 @@ var Based = (function () {
     function Based() {
         var arg = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            arg[_i - 0] = arguments[_i];
+            arg[_i] = arguments[_i];
         }
     }
     return Based;

tests/baselines/reference/checkSuperCallBeforeThisAccessing6.js

@@ -20,7 +20,7 @@ var Base = (function () {
     function Base() {
         var arg = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            arg[_i - 0] = arguments[_i];
+            arg[_i] = arguments[_i];
         }
     }
     return Base;

tests/baselines/reference/checkSuperCallBeforeThisAccessing8.js

@@ -20,7 +20,7 @@ var Base = (function () {
     function Base() {
         var arg = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            arg[_i - 0] = arguments[_i];
+            arg[_i] = arguments[_i];
         }
     }
     return Base;

tests/baselines/reference/collisionArgumentsArrowFunctions.js

@@ -37,7 +37,7 @@ var f1NoError = function (arguments) {
 var f2 = function () {
     var restParameters = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        restParameters[_i - 0] = arguments[_i];
+        restParameters[_i] = arguments[_i];
     }
     var arguments = 10; // No Error
 };

tests/baselines/reference/collisionArgumentsClassConstructor.js

@@ -118,7 +118,7 @@ var c2 = (function () {
     function c2() {
         var restParameters = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            restParameters[_i - 0] = arguments[_i];
+            restParameters[_i] = arguments[_i];
         }
         var arguments = 10; // no error
     }

tests/baselines/reference/collisionArgumentsClassMethod.js

@@ -94,7 +94,7 @@ var c3 = (function () {
     c3.prototype.foo = function () {
         var restParameters = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            restParameters[_i - 0] = arguments[_i];
+            restParameters[_i] = arguments[_i];
         }
         var arguments = 10; // no error
     };

tests/baselines/reference/collisionArgumentsFunction.js

@@ -66,7 +66,7 @@ function f1NoError(arguments) {
 function f3() {
     var restParameters = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        restParameters[_i - 0] = arguments[_i];
+        restParameters[_i] = arguments[_i];
     }
     var arguments = 10; // no error
 }

tests/baselines/reference/collisionArgumentsFunctionExpressions.js

@@ -56,7 +56,7 @@ function foo() {
     function f3() {
         var restParameters = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            restParameters[_i - 0] = arguments[_i];
+            restParameters[_i] = arguments[_i];
         }
         var arguments = 10; // no error
     }

tests/baselines/reference/collisionRestParameterArrowFunctions.js

@@ -27,7 +27,7 @@ var f1NoError = function (_i) {
 var f2 = function () {
     var restParameters = [];
     for (var _a = 0; _a < arguments.length; _a++) {
-        restParameters[_a - 0] = arguments[_a];
+        restParameters[_a] = arguments[_a];
     }
     var _i = 10; // No Error
 };

tests/baselines/reference/collisionRestParameterClassConstructor.js

@@ -88,7 +88,7 @@ var c2 = (function () {
     function c2() {
         var restParameters = [];
         for (var _a = 0; _a < arguments.length; _a++) {
-            restParameters[_a - 0] = arguments[_a];
+            restParameters[_a] = arguments[_a];
         }
         var _i = 10; // no error
     }

tests/baselines/reference/collisionRestParameterClassMethod.js

@@ -70,7 +70,7 @@ var c3 = (function () {
     c3.prototype.foo = function () {
         var restParameters = [];
         for (var _a = 0; _a < arguments.length; _a++) {
-            restParameters[_a - 0] = arguments[_a];
+            restParameters[_a] = arguments[_a];
         }
         var _i = 10; // no error
     };

tests/baselines/reference/collisionRestParameterFunction.js

@@ -48,7 +48,7 @@ function f1NoError(_i) {
 function f3() {
     var restParameters = [];
     for (var _a = 0; _a < arguments.length; _a++) {
-        restParameters[_a - 0] = arguments[_a];
+        restParameters[_a] = arguments[_a];
     }
     var _i = 10; // no error
 }

tests/baselines/reference/collisionRestParameterFunctionExpressions.js

@@ -39,7 +39,7 @@ function foo() {
     function f3() {
         var restParameters = [];
         for (var _a = 0; _a < arguments.length; _a++) {
-            restParameters[_a - 0] = arguments[_a];
+            restParameters[_a] = arguments[_a];
         }
         var _i = 10; // no error
     }

tests/baselines/reference/collisionRestParameterUnderscoreIUsage.js

@@ -14,7 +14,7 @@ var Foo = (function () {
     function Foo() {
         var args = [];
         for (var _a = 0; _a < arguments.length; _a++) {
-            args[_a - 0] = arguments[_a];
+            args[_a] = arguments[_a];
         }
         console.log(_i); // This should result in error
     }

tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js

@@ -297,7 +297,7 @@ var TypeScriptAllInOne;
         Program.Main = function () {
             var args = [];
             for (var _i = 0; _i < arguments.length; _i++) {
-                args[_i - 0] = arguments[_i];
+                args[_i] = arguments[_i];
             }
             try {
                 var bfs = new BasicFeatures();

tests/baselines/reference/contextuallyTypedIife.js

@@ -57,21 +57,21 @@ let eleven = (o => o.a(11))({ a: function(n) { return n; } });
 (function () {
     var numbers = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        numbers[_i - 0] = arguments[_i];
+        numbers[_i] = arguments[_i];
     }
     return numbers.every(function (n) { return n > 0; });
 })(5, 6, 7);
 (function () {
     var mixed = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        mixed[_i - 0] = arguments[_i];
+        mixed[_i] = arguments[_i];
     }
     return mixed.every(function (n) { return !!n; });
 })(5, 'oops', 'oh no');
 (function () {
     var noNumbers = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        noNumbers[_i - 0] = arguments[_i];
+        noNumbers[_i] = arguments[_i];
     }
     return noNumbers.some(function (n) { return n > 0; });
 })();

tests/baselines/reference/contextuallyTypingRestParameters.js

@@ -11,7 +11,7 @@ var x: (...y: string[]) => void = function (.../*3*/y) {
 var x = function () {
     var y = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        y[_i - 0] = arguments[_i];
+        y[_i] = arguments[_i];
     }
     var t = y;
     var x2 = t; // This should be error

tests/baselines/reference/declFileRestParametersOfFunctionAndFunctionType.js

@@ -14,7 +14,7 @@ var f6 = () => { return [<any>10]; }
 function f1() {
     var args = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        args[_i - 0] = arguments[_i];
+        args[_i] = arguments[_i];
     }
 }
 function f2(x) { }

tests/baselines/reference/declarationEmitDestructuringOptionalBindingParametersInOverloads.js

@@ -13,13 +13,13 @@ function foo2(...rest: any[]) {
 function foo() {
     var rest = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        rest[_i - 0] = arguments[_i];
+        rest[_i] = arguments[_i];
     }
 }
 function foo2() {
     var rest = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        rest[_i - 0] = arguments[_i];
+        rest[_i] = arguments[_i];
     }
 }
 

tests/baselines/reference/defaultExportWithOverloads01.js

@@ -10,7 +10,7 @@ export default function f(...args: any[]) {
 function f() {
     var args = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        args[_i - 0] = arguments[_i];
+        args[_i] = arguments[_i];
     }
 }
 Object.defineProperty(exports, "__esModule", { value: true });

tests/baselines/reference/destructuringParameterDeclaration4.js

@@ -43,31 +43,31 @@ foo1(1, 2, "string", E1.a, E.b);  // Error
 function a0() {
     var x = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        x[_i - 0] = arguments[_i];
+        x[_i] = arguments[_i];
     }
 } // Error, rest parameter must be array type
 function a1() {
     var x = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        x[_i - 0] = arguments[_i];
+        x[_i] = arguments[_i];
     }
 }
 function a2() {
     var a = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        a[_i - 0] = arguments[_i];
+        a[_i] = arguments[_i];
     }
 } // Error, rest parameter must be array type
 function a3() {
     var b = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        b[_i - 0] = arguments[_i];
+        b[_i] = arguments[_i];
     }
 } // Error, can't be optional
 function a4() {
     var b = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        b[_i - 0] = arguments[_i];
+        b[_i] = arguments[_i];
     }
 } // Error, can't have initializer
 function a5(_a) {
@@ -86,7 +86,7 @@ var C = (function () {
     function C() {
         var temp = [];
         for (var _i = 0; _i < arguments.length; _i++) {
-            temp[_i - 0] = arguments[_i];
+            temp[_i] = arguments[_i];
         }
         this.temp = temp;
     } // Error, rest parameter can't have properties
@@ -96,7 +96,7 @@ var C = (function () {
 function foo1() {
     var a = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        a[_i - 0] = arguments[_i];
+        a[_i] = arguments[_i];
     }
 }
 foo1(1, 2, "string", E1.a, E.b); // Error

tests/baselines/reference/destructuringParameterDeclaration6.js

@@ -40,20 +40,20 @@ while (, )
 function a5() {
     var  = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        [_i - 0] = arguments[_i];
+        [_i] = arguments[_i];
     }
 }
 while () { }
 function a6() {
     var public = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        public[_i - 0] = arguments[_i];
+        public[_i] = arguments[_i];
     }
 }
 function a7() {
     var a = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        a[_i - 0] = arguments[_i];
+        a[_i] = arguments[_i];
     }
 }
 a({ "while": 1 });

tests/baselines/reference/detachedCommentAtStartOfLambdaFunction1.js

@@ -19,7 +19,7 @@ var TestFile = (function () {
         return function () {
             var x = [];
             for (var _i = 0; _i < arguments.length; _i++) {
-                x[_i - 0] = arguments[_i];
+                x[_i] = arguments[_i];
             }
             /// <summary>Test summary</summary>
             /// <param name="message" type="String" />

tests/baselines/reference/detachedCommentAtStartOfLambdaFunction2.js

@@ -23,7 +23,7 @@ var TestFile = (function () {
             /// <returns type="Function" />
             var x = [];
             for (var _i = 0; _i < arguments.length; _i++) {
-                x[_i - 0] = arguments[_i];
+                x[_i] = arguments[_i];
             }
             return message + _this.name;
         };

tests/baselines/reference/disallowLineTerminatorBeforeArrow.js

@@ -92,13 +92,13 @@ var f4 = function (x, y) {
 var f5 = function () {
     var rest = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        rest[_i - 0] = arguments[_i];
+        rest[_i] = arguments[_i];
     }
 };
 var f6 = function () {
     var rest = [];
     for (var _i = 0; _i < arguments.length; _i++) {
-        rest[_i - 0] = arguments[_i];
+        rest[_i] = arguments[_i];
     }
 };
 var f7 = function (x, y, z) {