Typescript type inference issue Follow

Inside of a class I have the literal type variable definition as follows:

myData = {
header: "",
text: "",
}

Then I use it like this:

this.myData.header = "hello";

ReSharper tells me the error:

Cannot convert type '"hello"' to type '""': String literal types '"hello"' and '""' have different values

Shouldn't "hello" and "" be infered to string type here? (acc. to https://www.typescriptlang.org/docs/handbook/type-inference.html)

The infered string type works on compiler level correctly, because I do not get an error here. 

I've done the following workaround but I am thankful for clearing up whats right.

myData = {
header: <string>"",
text: <string>"",
}

many thanks!

I am using VS2015, ReSharper 2017.1.3 with language level 2.1 and compiler version 2.1.5