make it work with AssignmentRestElement

Author: ajafff

src/compiler/checker.ts

@@ -21066,7 +21066,7 @@ namespace ts {
                         else {
                             checkGrammarForDisallowedTrailingComma(node.elements, Diagnostics.A_rest_parameter_or_binding_pattern_may_not_have_a_trailing_comma);
                             const type = isTupleType(sourceType) ?
-                                getArrayLiteralType((sourceType.typeArguments || emptyArray).slice(elementIndex, getTypeReferenceArity(sourceType))) :
+                                sliceTupleType(sourceType, elementIndex) :
                                 createArrayType(elementType);
                             return checkDestructuringAssignment(restExpression, type, checkMode);
                         }

tests/baselines/reference/destructuringTuple.js

@@ -2,8 +2,13 @@
 declare var tuple: [boolean, number, ...string[]];
 
 const [a, b, c, ...rest] = tuple;
+
+declare var receiver: typeof tuple;
+
+[...receiver] = tuple;
 
 
 //// [destructuringTuple.js]
 "use strict";
 var a = tuple[0], b = tuple[1], c = tuple[2], rest = tuple.slice(3);
+receiver = tuple.slice(0);

tests/baselines/reference/destructuringTuple.symbols

@@ -9,3 +9,11 @@ const [a, b, c, ...rest] = tuple;
 >rest : Symbol(rest, Decl(destructuringTuple.ts, 2, 15))
 >tuple : Symbol(tuple, Decl(destructuringTuple.ts, 0, 11))
 
+declare var receiver: typeof tuple;
+>receiver : Symbol(receiver, Decl(destructuringTuple.ts, 4, 11))
+>tuple : Symbol(tuple, Decl(destructuringTuple.ts, 0, 11))
+
+[...receiver] = tuple;
+>receiver : Symbol(receiver, Decl(destructuringTuple.ts, 4, 11))
+>tuple : Symbol(tuple, Decl(destructuringTuple.ts, 0, 11))
+

tests/baselines/reference/destructuringTuple.types

@@ -9,3 +9,14 @@ const [a, b, c, ...rest] = tuple;
 >rest : string[]
 >tuple : [boolean, number, ...string[]]
 
+declare var receiver: typeof tuple;
+>receiver : [boolean, number, ...string[]]
+>tuple : [boolean, number, ...string[]]
+
+[...receiver] = tuple;
+>[...receiver] = tuple : [boolean, number, ...string[]]
+>[...receiver] : (string | number | boolean)[]
+>...receiver : string | number | boolean
+>receiver : [boolean, number, ...string[]]
+>tuple : [boolean, number, ...string[]]
+

tests/baselines/reference/restElementWithAssignmentPattern3.errors.txt

@@ -1,14 +1,9 @@
-tests/cases/conformance/es6/destructuring/restElementWithAssignmentPattern4.ts(3,10): error TS2322: Type 'string | number' is not assignable to type 'string'.
-  Type 'number' is not assignable to type 'string'.
-tests/cases/conformance/es6/destructuring/restElementWithAssignmentPattern4.ts(3,18): error TS2459: Type '(string | number)[]' has no property 'b' and no string index signature.
+tests/cases/conformance/es6/destructuring/restElementWithAssignmentPattern4.ts(3,18): error TS2459: Type '[string, number]' has no property 'b' and no string index signature.
 
 
-==== tests/cases/conformance/es6/destructuring/restElementWithAssignmentPattern4.ts (2 errors) ====
+==== tests/cases/conformance/es6/destructuring/restElementWithAssignmentPattern4.ts (1 errors) ====
     var a: string, b: number;
     var tuple: [string, number] = ["", 1];
     [...{ 0: a = "", b }] = tuple;
-             ~
-!!! error TS2322: Type 'string | number' is not assignable to type 'string'.
-!!! error TS2322:   Type 'number' is not assignable to type 'string'.
                      ~
-!!! error TS2459: Type '(string | number)[]' has no property 'b' and no string index signature.
+!!! error TS2459: Type '[string, number]' has no property 'b' and no string index signature.

tests/baselines/reference/restElementWithAssignmentPattern4.errors.txt

@@ -3,3 +3,7 @@
 declare var tuple: [boolean, number, ...string[]];
 
 const [a, b, c, ...rest] = tuple;
+
+declare var receiver: typeof tuple;
+
+[...receiver] = tuple;