nameof.ts

/**
 * Extracts the property name from a property expression function.
 * @param fn The function.
 * @return The property name.
 */
function nameof(fn: Function): string {
  var body = fn ? fn.toString() : null;
  var lambdaExpression = body ? body.match(/(?:=>|return)\s*(.+?)\s*(?:;|}|$)/) : null;
  var propertyExpression = lambdaExpression ? lambdaExpression[1].match(/\.\s*(.+?)\s*$/) : null;
  if (propertyExpression != null) {
    return propertyExpression[1];
  } else {
    throw new Error('Invalid property expression: ' + body);
  }
}

// Test it.
interface ITest {
  someKindOfProperty: number;
}
var testObject: ITest = {
	someKindOfProperty: 10
};

console.log(nameof(function() { return testObject.someKindOfProperty; }));
console.log(nameof(() => testObject.someKindOfProperty));