console.assert()

assert(assertion, obj1);
assert(assertion, obj1, obj2);
assert(assertion, obj1, obj2, /* … ,*/ objN);
assert(assertion, msg);
assert(assertion, msg, subst1);
assert(assertion, msg, subst1, /* … ,*/ substN);

const errorMsg = "the # is not even";
for (let number = 2; number <= 5; number++) {
  console.log(`the # is ${number}`);
  console.assert(number % 2 === 0, { number, errorMsg });
}
// output:
// the # is 2
// the # is 3
// Assertion failed: {number: 3, errorMsg: "the # is not even"}
// the # is 4
// the # is 5
// Assertion failed: {number: 5, errorMsg: "the # is not even"}