Property with string literal type serializes as 'Object'

[JohnWeisz]

Properties with string literal types are serialized and deserialized as Object. This is caused by the Typescript compiler, which emits incorrect metadata information for these types. See microsoft/TypeScript#10809

For example, the following code will produce incorrect behavior if ReflectDecorators is used to automatically detect types:

@JsonObject
class Person {
    @JsonMember
    public name: "John" | "James";
}

The solution, until this is fixed by the TypeScript team, is to manually define the type setting:

@JsonObject
class Person {
    @JsonMember({ type: String })
    public name: "John" | "James";
}

This will raise a warning in the console however, indicating that the specified type does not match detected type:

@JsonMember: 'type' specified for 'Person.name' does not match detected type.

Since this otherwise potentially helpful warning only occurrs temporarily until the fix is shipped by Microsoft, no action will be done to suppress it in these cases.

[JohnWeisz]

Fixed in microsoft/TypeScript#10809