TestHelper.ts

type funcPropNames<T> = {
	[prop in keyof T]: T[prop] extends Function ? prop : never;
}[keyof T];
​
type FunctionProps<T> = Pick<T, funcPropNames<T>>;
​
export type Spied<T> = {
	[k in keyof T]: k extends FunctionProps<T> ? jasmine.Spy : T;
};
​
let spyOnClass = <T extends { new (...args: any[]): any }, U>(type: T, constructorArgs?: U) => {
	let ctorArgs = Object.keys(constructorArgs).map(k => constructorArgs[k]);
	let ctor = new type(...ctorArgs);
​
	let spyOnFunctions = (obj: Object) => {
		if (obj instanceof Object) {
			Object.keys(obj).forEach(p => {
				if(!!obj) {
					if (obj[p] instanceof Function) {
						spyOn(obj, p as any);
					} else {
						obj[p] = spyOnFunctions(obj[p]);
					}
				}
			});
		}
		console.log(obj);
		return obj;
	}
​
	return spyOnFunctions(ctor) as Spied<T>;
};