Heterogeneous array serialization not working as expected

[monesidn]

NOTE: This is part of a series of issues I'm creating to keep track of the work I've done, and that will be submitted, across multiple PRs

Currently when serializing an array containing heterogeneous objects without providing an explicit schema, the schema of the first item is used for all. This is highly counter-intuitive.

See this example:

class Person {
    @serializable name: string;
    @serializable surname: string;
}

class Car {
    @serializable model: string;
    @serializable color: string;
}

const serialized = serialize([
    Object.assign(new Person(), {
        name: "John",
        surname: "Doe",
    }),
    Object.assign(new Car(), {
        model: "Fiat 500",
        color: "Red",
    }),
]);

// Expected:
// [
//     {
//         name: "John",
//         surname: "Doe",
//     },
//     {
//         model: "Fiat 500",
//         color: "Red",
//     },
// ];

// Found:
// [
//     { name: "John", surname: "Doe" },
//     { name: undefined, surname: undefined },
// ];

To solve this problem when serializing an array the actual schema (if not provided) should be inferred on a per-element basis.