Typescript interface property to string

Update 2019: This answer is outdated, please look at the update added directly into the question.

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basarat answer is a good idea, but it doesn't work with interfaces.

You can't write methodX(interfacePropertyToString(()=>interfaceX.porpertyname), objectX) because interfaceX is not an object.

Interfaces are abstractions and they are used only for TypeScript, they doesn't exist in Javascript.

But thanks to his answer i found out the solution : using a parameter in the method.

Finally we have :

    interfacePropertyToString = ( property: (object: any) => void ) => {
        var chaine = property.toString();
        var arr = chaine.match( /[\s\S]*{[\s\S]*\.([^\.; ]*)[ ;\n]*}/ );
        return arr[1];
    };

We have to use [\s\S] to be able to match on multilines because Typescript convert (object: Interface) => {object.code;} to a multiline function.

Now you can use it as you want :

        interfacePropertyToString(( o: Interface ) => { o.interfaceProperty});
        interfacePropertyToString( function ( o: Interface  ) { o.interfaceProperty});

You could write a function to parse the body of a function to find the name e.g.:

methodX(getName(()=>something.name), objectX)

Where getName will do a toString on the function body to get a string of the form "function(){return something.name}" and then parse it to get "name".

Note: however this has a tendency to break depending upon how you minify it.

I've changed basarat code a little bit, so we can use it as generic:

const P = <T>( property: (object: T) => void ) => {
    const chaine = property.toString();
    const arr = chaine.match( /[\s\S]*{[\s\S]*\.([^\.; ]*)[ ;\n]*}/ );
    return arr[1];
};

And example usage:

console.log(P<MyInterface>(p => p.propertyName));