Forward defined types not properly defined in TypeScript

[pepone]

slice2js wrongly assumes that a forward defined type is defined in the file where the forward declaration is found.

slice2js needs to be aware where the actual definition for a type is when generating the TypeScript definitions, that is required in order to generate the corresponding import statements.

To solve this we will introduce a new metadata directive js:defined-in:<Path> where <Path> is the relative path to the Slice file containing the definition for the given type, the metadata applies to forward definitions.

// forward.ice
module Demo
{
["js:defined-in:point.ice"]
class Point;
}

// point.ice
module Demo
{
class Point
{
    int x;
    int y;
};
}

// line.ice
#include <forward.ice>

module Demo
{
class Line
{
    Point x;
    Point y;
}
}

The generated code will correctly import the defined-in file, instead of the file containing the forward declaration:

import * as iceNS0 from "ice"
import * as iceNS1 from "./point"

export namespace Demo
{
    class Line extends iceNS0.Ice.Value
    {
        /**
         * One-shot constructor to initialize all data members.
         */
        constructor(x?:iceNS1.Demo.Point, y?:iceNS1.Demo.Point);
        x:iceNS1.Demo.Point;
        y:iceNS1.Demo.Point;
    }
}