ECMAScript 6 arrow function that returns an object

You must wrap the returning object literal into parentheses. Otherwise curly braces will be considered to denote the function’s body. The following works:

p => ({ foo: 'bar' });

You don’t need to wrap any other expression into parentheses:

p => 10;
p => 'foo';
p => true;
p => [1,2,3];
p => null;
p => /^foo$/;

and so on.

Reference: MDN – Returning object literals