Disallow binding patterns in rest parameters

src/compiler/checker.ts

@@ -12243,6 +12243,10 @@ module ts {
                         return grammarErrorOnNode(parameter.dotDotDotToken, Diagnostics.A_rest_parameter_must_be_last_in_a_parameter_list);
                     }
 
+                    if (parameter.name.kind === SyntaxKind.ArrayBindingPattern || parameter.name.kind === SyntaxKind.ObjectBindingPattern) {
+                        return grammarErrorOnNode(parameter.name, Diagnostics.A_rest_element_cannot_contain_a_binding_pattern);
+                    }
+
                     if (parameter.questionToken) {
                         return grammarErrorOnNode(parameter.questionToken, Diagnostics.A_rest_parameter_cannot_be_optional);
                     }

tests/baselines/reference/iterableArrayPattern14.errors.txt

@@ -0,0 +1,22 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern14.ts(1,17): error TS2501: A rest element cannot contain a binding pattern.
+
+
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern14.ts (1 errors) ====
+    function fun(...[a, ...b]) { }
+                    ~~~~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
+    fun(new FooIterator);
+    class Bar { x }
+    class Foo extends Bar { y }
+    class FooIterator {
+        next() {
+            return {
+                value: new Foo,
+                done: false
+            };
+        }
+    
+        [Symbol.iterator]() {
+            return this;
+        }
+    }

tests/baselines/reference/iterableArrayPattern14.types

@@ -1,51 +0,0 @@
-=== tests/cases/conformance/es6/destructuring/iterableArrayPattern14.ts ===
-function fun(...[a, ...b]) { }
->fun : (...[a, ...b]: any[]) => void, Symbol(fun, Decl(iterableArrayPattern14.ts, 0, 0))
->a : any, Symbol(a, Decl(iterableArrayPattern14.ts, 0, 17))
->b : any[], Symbol(b, Decl(iterableArrayPattern14.ts, 0, 19))
-
-fun(new FooIterator);
->fun(new FooIterator) : void
->fun : (...[a, ...b]: any[]) => void, Symbol(fun, Decl(iterableArrayPattern14.ts, 0, 0))
->new FooIterator : FooIterator
->FooIterator : typeof FooIterator, Symbol(FooIterator, Decl(iterableArrayPattern14.ts, 3, 27))
-
-class Bar { x }
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern14.ts, 1, 21))
->x : any, Symbol(x, Decl(iterableArrayPattern14.ts, 2, 11))
-
-class Foo extends Bar { y }
->Foo : Foo, Symbol(Foo, Decl(iterableArrayPattern14.ts, 2, 15))
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern14.ts, 1, 21))
->y : any, Symbol(y, Decl(iterableArrayPattern14.ts, 3, 23))
-
-class FooIterator {
->FooIterator : FooIterator, Symbol(FooIterator, Decl(iterableArrayPattern14.ts, 3, 27))
-
-    next() {
->next : () => { value: Foo; done: boolean; }, Symbol(next, Decl(iterableArrayPattern14.ts, 4, 19))
-
-        return {
->{            value: new Foo,            done: false        } : { value: Foo; done: boolean; }
-
-            value: new Foo,
->value : Foo, Symbol(value, Decl(iterableArrayPattern14.ts, 6, 16))
->new Foo : Foo
->Foo : typeof Foo, Symbol(Foo, Decl(iterableArrayPattern14.ts, 2, 15))
-
-            done: false
->done : boolean, Symbol(done, Decl(iterableArrayPattern14.ts, 7, 27))
->false : boolean
-
-        };
-    }
-
-    [Symbol.iterator]() {
->Symbol.iterator : symbol, Symbol(SymbolConstructor.iterator, Decl(lib.d.ts, 1236, 31))
->Symbol : SymbolConstructor, Symbol(Symbol, Decl(lib.d.ts, 1186, 52), Decl(lib.d.ts, 1262, 11))
->iterator : symbol, Symbol(SymbolConstructor.iterator, Decl(lib.d.ts, 1236, 31))
-
-        return this;
->this : FooIterator, Symbol(FooIterator, Decl(iterableArrayPattern14.ts, 3, 27))
-    }
-}

tests/baselines/reference/iterableArrayPattern15.errors.txt

@@ -0,0 +1,22 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern15.ts(1,17): error TS2501: A rest element cannot contain a binding pattern.
+
+
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern15.ts (1 errors) ====
+    function fun(...[a, b]: Bar[]) { }
+                    ~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
+    fun(...new FooIterator);
+    class Bar { x }
+    class Foo extends Bar { y }
+    class FooIterator {
+        next() {
+            return {
+                value: new Foo,
+                done: false
+            };
+        }
+    
+        [Symbol.iterator]() {
+            return this;
+        }
+    }

tests/baselines/reference/iterableArrayPattern15.types

@@ -1,53 +0,0 @@
-=== tests/cases/conformance/es6/destructuring/iterableArrayPattern15.ts ===
-function fun(...[a, b]: Bar[]) { }
->fun : (...[a, b]: Bar[]) => void, Symbol(fun, Decl(iterableArrayPattern15.ts, 0, 0))
->a : Bar, Symbol(a, Decl(iterableArrayPattern15.ts, 0, 17))
->b : Bar, Symbol(b, Decl(iterableArrayPattern15.ts, 0, 19))
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern15.ts, 1, 24))
-
-fun(...new FooIterator);
->fun(...new FooIterator) : void
->fun : (...[a, b]: Bar[]) => void, Symbol(fun, Decl(iterableArrayPattern15.ts, 0, 0))
->...new FooIterator : Foo
->new FooIterator : FooIterator
->FooIterator : typeof FooIterator, Symbol(FooIterator, Decl(iterableArrayPattern15.ts, 3, 27))
-
-class Bar { x }
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern15.ts, 1, 24))
->x : any, Symbol(x, Decl(iterableArrayPattern15.ts, 2, 11))
-
-class Foo extends Bar { y }
->Foo : Foo, Symbol(Foo, Decl(iterableArrayPattern15.ts, 2, 15))
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern15.ts, 1, 24))
->y : any, Symbol(y, Decl(iterableArrayPattern15.ts, 3, 23))
-
-class FooIterator {
->FooIterator : FooIterator, Symbol(FooIterator, Decl(iterableArrayPattern15.ts, 3, 27))
-
-    next() {
->next : () => { value: Foo; done: boolean; }, Symbol(next, Decl(iterableArrayPattern15.ts, 4, 19))
-
-        return {
->{            value: new Foo,            done: false        } : { value: Foo; done: boolean; }
-
-            value: new Foo,
->value : Foo, Symbol(value, Decl(iterableArrayPattern15.ts, 6, 16))
->new Foo : Foo
->Foo : typeof Foo, Symbol(Foo, Decl(iterableArrayPattern15.ts, 2, 15))
-
-            done: false
->done : boolean, Symbol(done, Decl(iterableArrayPattern15.ts, 7, 27))
->false : boolean
-
-        };
-    }
-
-    [Symbol.iterator]() {
->Symbol.iterator : symbol, Symbol(SymbolConstructor.iterator, Decl(lib.d.ts, 1236, 31))
->Symbol : SymbolConstructor, Symbol(Symbol, Decl(lib.d.ts, 1186, 52), Decl(lib.d.ts, 1262, 11))
->iterator : symbol, Symbol(SymbolConstructor.iterator, Decl(lib.d.ts, 1236, 31))
-
-        return this;
->this : FooIterator, Symbol(FooIterator, Decl(iterableArrayPattern15.ts, 3, 27))
-    }
-}

tests/baselines/reference/iterableArrayPattern16.errors.txt

@@ -1,9 +1,12 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts(1,17): error TS2501: A rest element cannot contain a binding pattern.
 tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts(2,5): error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[Bar, Bar]'.
   Property '0' is missing in type 'FooIterator'.
 
 
-==== tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern16.ts (2 errors) ====
     function fun(...[a, b]: [Bar, Bar][]) { }
+                    ~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
     fun(...new FooIteratorIterator);
         ~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[Bar, Bar]'.

tests/baselines/reference/iterableArrayPattern17.errors.txt

@@ -1,9 +1,12 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern17.ts(1,17): error TS2501: A rest element cannot contain a binding pattern.
 tests/cases/conformance/es6/destructuring/iterableArrayPattern17.ts(2,5): error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type 'Bar'.
   Property 'x' is missing in type 'FooIterator'.
 
 
-==== tests/cases/conformance/es6/destructuring/iterableArrayPattern17.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern17.ts (2 errors) ====
     function fun(...[a, b]: Bar[]) { }
+                    ~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
     fun(new FooIterator);
         ~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type 'Bar'.

tests/baselines/reference/iterableArrayPattern20.errors.txt

@@ -0,0 +1,22 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern20.ts(1,17): error TS2501: A rest element cannot contain a binding pattern.
+
+
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern20.ts (1 errors) ====
+    function fun(...[[a = new Foo], b = [new Foo]]: Bar[][]) { }
+                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
+    fun(...new FooArrayIterator);
+    class Bar { x }
+    class Foo extends Bar { y }
+    class FooArrayIterator {
+        next() {
+            return {
+                value: [new Foo],
+                done: false
+            };
+        }
+    
+        [Symbol.iterator]() {
+            return this;
+        }
+    }

tests/baselines/reference/iterableArrayPattern20.types

@@ -1,59 +0,0 @@
-=== tests/cases/conformance/es6/destructuring/iterableArrayPattern20.ts ===
-function fun(...[[a = new Foo], b = [new Foo]]: Bar[][]) { }
->fun : (...[[a = new Foo], b = [new Foo]]: Bar[][]) => void, Symbol(fun, Decl(iterableArrayPattern20.ts, 0, 0))
->a : Bar, Symbol(a, Decl(iterableArrayPattern20.ts, 0, 18))
->new Foo : Foo
->Foo : typeof Foo, Symbol(Foo, Decl(iterableArrayPattern20.ts, 2, 15))
->b : Bar[], Symbol(b, Decl(iterableArrayPattern20.ts, 0, 31))
->[new Foo] : Foo[]
->new Foo : Foo
->Foo : typeof Foo, Symbol(Foo, Decl(iterableArrayPattern20.ts, 2, 15))
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern20.ts, 1, 29))
-
-fun(...new FooArrayIterator);
->fun(...new FooArrayIterator) : void
->fun : (...[[a = new Foo], b = [new Foo]]: Bar[][]) => void, Symbol(fun, Decl(iterableArrayPattern20.ts, 0, 0))
->...new FooArrayIterator : Foo[]
->new FooArrayIterator : FooArrayIterator
->FooArrayIterator : typeof FooArrayIterator, Symbol(FooArrayIterator, Decl(iterableArrayPattern20.ts, 3, 27))
-
-class Bar { x }
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern20.ts, 1, 29))
->x : any, Symbol(x, Decl(iterableArrayPattern20.ts, 2, 11))
-
-class Foo extends Bar { y }
->Foo : Foo, Symbol(Foo, Decl(iterableArrayPattern20.ts, 2, 15))
->Bar : Bar, Symbol(Bar, Decl(iterableArrayPattern20.ts, 1, 29))
->y : any, Symbol(y, Decl(iterableArrayPattern20.ts, 3, 23))
-
-class FooArrayIterator {
->FooArrayIterator : FooArrayIterator, Symbol(FooArrayIterator, Decl(iterableArrayPattern20.ts, 3, 27))
-
-    next() {
->next : () => { value: Foo[]; done: boolean; }, Symbol(next, Decl(iterableArrayPattern20.ts, 4, 24))
-
-        return {
->{            value: [new Foo],            done: false        } : { value: Foo[]; done: boolean; }
-
-            value: [new Foo],
->value : Foo[], Symbol(value, Decl(iterableArrayPattern20.ts, 6, 16))
->[new Foo] : Foo[]
->new Foo : Foo
->Foo : typeof Foo, Symbol(Foo, Decl(iterableArrayPattern20.ts, 2, 15))
-
-            done: false
->done : boolean, Symbol(done, Decl(iterableArrayPattern20.ts, 7, 29))
->false : boolean
-
-        };
-    }
-
-    [Symbol.iterator]() {
->Symbol.iterator : symbol, Symbol(SymbolConstructor.iterator, Decl(lib.d.ts, 1236, 31))
->Symbol : SymbolConstructor, Symbol(Symbol, Decl(lib.d.ts, 1186, 52), Decl(lib.d.ts, 1262, 11))
->iterator : symbol, Symbol(SymbolConstructor.iterator, Decl(lib.d.ts, 1236, 31))
-
-        return this;
->this : FooArrayIterator, Symbol(FooArrayIterator, Decl(iterableArrayPattern20.ts, 3, 27))
-    }
-}

tests/baselines/reference/iterableArrayPattern25.errors.txt

@@ -1,8 +1,11 @@
 tests/cases/conformance/es6/destructuring/iterableArrayPattern25.ts(1,30): error TS2370: A rest parameter must be of an array type.
+tests/cases/conformance/es6/destructuring/iterableArrayPattern25.ts(1,33): error TS2501: A rest element cannot contain a binding pattern.
 
 
-==== tests/cases/conformance/es6/destructuring/iterableArrayPattern25.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern25.ts (2 errors) ====
     function takeFirstTwoEntries(...[[k1, v1], [k2, v2]]) { }
                                  ~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2370: A rest parameter must be of an array type.
+                                    ~~~~~~~~~~~~~~~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
     takeFirstTwoEntries(new Map([["", 0], ["hello", 1]]));

tests/baselines/reference/iterableArrayPattern26.errors.txt

@@ -1,9 +1,12 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern26.ts(1,33): error TS2501: A rest element cannot contain a binding pattern.
 tests/cases/conformance/es6/destructuring/iterableArrayPattern26.ts(2,21): error TS2345: Argument of type 'Map<string, number>' is not assignable to parameter of type '[string, number]'.
   Property '0' is missing in type 'Map<string, number>'.
 
 
-==== tests/cases/conformance/es6/destructuring/iterableArrayPattern26.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern26.ts (2 errors) ====
     function takeFirstTwoEntries(...[[k1, v1], [k2, v2]]: [string, number][]) { }
+                                    ~~~~~~~~~~~~~~~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
     takeFirstTwoEntries(new Map([["", 0], ["hello", 1]]));
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type 'Map<string, number>' is not assignable to parameter of type '[string, number]'.

tests/baselines/reference/iterableArrayPattern27.errors.txt

@@ -0,0 +1,8 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern27.ts(1,33): error TS2501: A rest element cannot contain a binding pattern.
+
+
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern27.ts (1 errors) ====
+    function takeFirstTwoEntries(...[[k1, v1], [k2, v2]]: [string, number][]) { }
+                                    ~~~~~~~~~~~~~~~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
+    takeFirstTwoEntries(...new Map([["", 0], ["hello", 1]]));

tests/baselines/reference/iterableArrayPattern27.types

@@ -1,22 +0,0 @@
-=== tests/cases/conformance/es6/destructuring/iterableArrayPattern27.ts ===
-function takeFirstTwoEntries(...[[k1, v1], [k2, v2]]: [string, number][]) { }
->takeFirstTwoEntries : (...[[k1, v1], [k2, v2]]: [string, number][]) => void, Symbol(takeFirstTwoEntries, Decl(iterableArrayPattern27.ts, 0, 0))
->k1 : string, Symbol(k1, Decl(iterableArrayPattern27.ts, 0, 34))
->v1 : number, Symbol(v1, Decl(iterableArrayPattern27.ts, 0, 37))
->k2 : string, Symbol(k2, Decl(iterableArrayPattern27.ts, 0, 44))
->v2 : number, Symbol(v2, Decl(iterableArrayPattern27.ts, 0, 47))
-
-takeFirstTwoEntries(...new Map([["", 0], ["hello", 1]]));
->takeFirstTwoEntries(...new Map([["", 0], ["hello", 1]])) : void
->takeFirstTwoEntries : (...[[k1, v1], [k2, v2]]: [string, number][]) => void, Symbol(takeFirstTwoEntries, Decl(iterableArrayPattern27.ts, 0, 0))
->...new Map([["", 0], ["hello", 1]]) : [string, number]
->new Map([["", 0], ["hello", 1]]) : Map<string, number>
->Map : MapConstructor, Symbol(Map, Decl(lib.d.ts, 1837, 1), Decl(lib.d.ts, 1859, 11))
->[["", 0], ["hello", 1]] : [string, number][]
->["", 0] : [string, number]
->"" : string
->0 : number
->["hello", 1] : [string, number]
->"hello" : string
->1 : number
-

tests/baselines/reference/iterableArrayPattern28.errors.txt

@@ -1,9 +1,12 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern28.ts(1,33): error TS2501: A rest element cannot contain a binding pattern.
 tests/cases/conformance/es6/destructuring/iterableArrayPattern28.ts(2,28): error TS2453: The type argument for type parameter 'V' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'boolean'.
 
 
-==== tests/cases/conformance/es6/destructuring/iterableArrayPattern28.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern28.ts (2 errors) ====
     function takeFirstTwoEntries(...[[k1, v1], [k2, v2]]: [string, number][]) { }
+                                    ~~~~~~~~~~~~~~~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
     takeFirstTwoEntries(...new Map([["", 0], ["hello", true]]));
                                ~~~
 !!! error TS2453: The type argument for type parameter 'V' cannot be inferred from the usage. Consider specifying the type arguments explicitly.

tests/baselines/reference/iterableArrayPattern29.errors.txt

@@ -1,10 +1,13 @@
+tests/cases/conformance/es6/destructuring/iterableArrayPattern29.ts(1,33): error TS2501: A rest element cannot contain a binding pattern.
 tests/cases/conformance/es6/destructuring/iterableArrayPattern29.ts(2,21): error TS2345: Argument of type '[string, boolean]' is not assignable to parameter of type '[string, number]'.
   Types of property '1' are incompatible.
     Type 'boolean' is not assignable to type 'number'.
 
 
-==== tests/cases/conformance/es6/destructuring/iterableArrayPattern29.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/iterableArrayPattern29.ts (2 errors) ====
     function takeFirstTwoEntries(...[[k1, v1], [k2, v2]]: [string, number][]) { }
+                                    ~~~~~~~~~~~~~~~~~~~~
+!!! error TS2501: A rest element cannot contain a binding pattern.
     takeFirstTwoEntries(...new Map([["", true], ["hello", true]]));
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type '[string, boolean]' is not assignable to parameter of type '[string, number]'.