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) ==== function fun(...[a, b]: [Bar, Bar][]) { } fun(...new FooIteratorIterator); ~~~~~~~~~~~~~~~~~~~~~~~~~~ !!! error TS2345: Argument of type 'FooIterator' is not assignable to parameter of type '[Bar, Bar]'. !!! error TS2345: Property '0' is missing in type 'FooIterator'. class Bar { x } class Foo extends Bar { y } class FooIterator { next() { return { value: new Foo, done: false }; } [Symbol.iterator]() { return this; } } class FooIteratorIterator { next() { return { value: new FooIterator, done: false }; } [Symbol.iterator]() { return this; } }