bug: constructor parameter members initialized in wrong order

[trusktr]

Given the code

class Foo {
  c: number = this.a + this.b
  constructor(public a: number, public b: number) { }
}

const f = new Foo(1, 2)

the value of f.c should be 3, but it is 0.

This assemblyscript playground example shows 0.

This equivalent TypeScript playground example shows the expected 3.

[dcodeIO]

Initialization order should be:

• Set provided values of this.a and this.b + implement "TS2333: 'this' cannot be referenced in constructor arguments." to account for parameter initializes like public a: number = this.c, which would be invalid
• Execute field initializers, here set this.c
• Execute constructor body

[dcodeIO]

Interesting oddity: Locally I get a "TS2729: Property is used before its initialization" on c: i32 = this.a + this.b at .a and .b, while in the TS playground I don't. Any ideas? :)

[trusktr]

Interesting oddity: Locally I get a "TS2729: Property is used before its initialization" on c: i32 = this.a + this.b at .a and .b, while in the TS playground I don't. Any ideas? :)

I see you merged it, so I assume you already figured the answer to that?

[dcodeIO]

I still don't know why that's different in their playground and locally, but let me know if you have an idea :) Was suspecting a differing config option, but couldn't find the one that is responsible.