Merge pull request #12217 from subzey/feature/rest-loop-index

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

Author: mhegazy

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
     };