Add optional types to function/method declarations

test/mjsunit/harmony/typesystem/method-definitions.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-types
+
+
+load("test/mjsunit/harmony/typesystem/testgen.js");
+
+
+(function TestMethodDefinitions() {
+  // Normal methods.
+  CheckValid("class C { m(a: number, b: number) { return a+b; } }");
+  CheckValid("class C { m(a: number, b?: number) { return a; } }");
+  CheckValid("class C { m(a?: number, b?: number) { return 42; } }");
+  CheckValid("class C { m(a: number, ...rest: number[]) {} }");
+  CheckValid("class C { m(a?: number, ...rest: number[]) {} }");
+  CheckValid("class C { m() : boolean { return true; } }");
+  CheckValid("class C { m(a: number, b: number) : boolean { return true; } }");
+  CheckValid("class C { m(a: number, b?: number) : boolean { return true; } }");
+  CheckValid("class C { m(a?: number, b?: number) : boolean { return true; } }");
+  CheckValid("class C { m(a: number, ...rest: number[]) : void {} }");
+  CheckValid("class C { m(a: number, ...rest: number[]) : void {} }");
+  CheckValid("class C { m([first, ...rest]: number[]) : void {} }");
+  CheckValid("class C { m(a: number = 7, b: number) { return a+b; } }");
+  CheckValid("class C { m(a: number = 1, b?: number) { return a; } }");
+  CheckValid("class C { m(a: number = 2, ...rest: number[]) {} }");
+  CheckValid("class C { m(a: number = 1, b: number) : boolean { return true; } }");
+  CheckValid("class C { m(a: number = 1, b?: number) : boolean { return true; } }");
+  CheckValid("class C { m(a: number = 1, ...rest: number[]) : void {} }");
+  CheckValid("class C { m([first, ...rest]: number[] = [1]) : void {} }");
+  // Type parametric.
+  CheckValid("class C { m <A>(a: A, b: A) { return a+b; } }");
+  CheckValid("class C { m <A extends number>(a: A, b: A) { return a+b; } }");
+  CheckValid("class C { m <A, B>(a: A, b: B) { return a+b; } }");
+  CheckValid("class C { m <A extends number, B extends number>(a: A, b: B) { return a+b; } }");
+  // Constructors.
+  CheckValid("class C { constructor () {} }");
+  CheckValid("class C { constructor (a : number) {} }");
+  CheckValid("class C { constructor (a? : number) {} }");
+  CheckValid("class C { constructor (a : number, b : string) {} }");
+  CheckValid("class C { constructor (a, b? : string) {} }");
+  CheckValid("class C { constructor (a, b? : string, ...rest: any[]) {} }");
+  // Getters.
+  CheckValid("class C { get x () { return 42; } }");
+  CheckValid("class C { get x () : number { return 42; } }");
+  // Setters.
+  CheckValid("class C { set x (a) {} }");
+  CheckValid("class C { set x (a) : void {} }");
+  CheckValid("class C { set x (a : number) {} }");
+  CheckValid("class C { set x (a : number) : void {} }");
+  // Invalid constructors.
+  CheckInvalid("class C { constructor (a : number) : boolean {} }");
+  CheckInvalid("class C { constructor <A>(a : A) {} }");
+  // Invalid getters.

[rossberg, 2016/04/18 09:22:24]

What about "get x(y?) {}"?

[nickie, 2016/04/19 10:58:10]

Done.

+  CheckInvalid("class C { get x (a) { return 42; } }");
+  CheckInvalid("class C { get x (a) : number { return 42; } }");
+  CheckInvalid("class C { get x (a, b) { return 42; } }");
+  CheckInvalid("class C { get x (a, b) : number { return 42; } }");
+  CheckInvalid("class C { get x (a : number) { return 42; } }");
+  CheckInvalid("class C { get x (a : number) : number { return 42; } }");
+  CheckInvalid("class C { get x <A>() { return 42; } }");
+  // Invalid setters.

[rossberg, 2016/04/18 09:22:24]

Same here: "set x(y?) {}", is that legal?

[nickie, 2016/04/19 10:58:10]

It's not legal and unfortunately it passes.  I'm adding a bug fix and some
tests.

Also, according to TS, the parameter to a setter should not have an initializer.
 But this is not consistent with ES6, so we allow initializers here (I'm not
adding tests for that).  Our untyped V8 allows:

d8> class D { set x(a=42) {print(a);} };
class D { set x(a=42) {print(a);} }
d8> var o = new D;
d8> o.x = 17;
17
17
d8> o.x = undefined;
42

+  CheckInvalid("class C { set x () {} }");
+  CheckInvalid("class C { set x () : void {} }");
+  CheckInvalid("class C { set x (a : number, b : number) {} }");
+  CheckInvalid("class C { set x (a : number, b : number) : void {} }");
+  CheckInvalid("class C { set x (...rest) {} }");
+  CheckInvalid("class C { set x (...rest : string[]) : void {} }");
+  CheckInvalid("class C { set x <A>(a : A) {} }");
+})();