import { adder } from "../src/simple" ; describe ( "simple" , ( ) => { it ( "adder can add 2 numbers" , ( ) => { expect ( adder ( 1 , 4 ) ) . toBe ( 5 ) ; } ) ; it ( "Array.prototype.includes works" , ( ) => { const result = [ 1 , 2 , 3 ] . includes ( 2 ) ; expect ( result ) . toBe ( true ) ; } ) ; it ( "Exponentiation operator works" , ( ) => { expect ( 1 ** 2 === Math . pow ( 1 , 2 ) ) . toBe ( true ) ; } ) ; } ) ;