Ensure

Implement the ensure function so that it throws an error if called without arguments or the argument is undefined. Otherwise it should return the given value.

ECMAScript 7

Show starting code

function ensure(value) {
  // Your code goes here
}

try {
  console.log(ensure());
} catch(err) {
  console.log(err);
}

No argument throws an error: Wrong answer
Truthy argument returns argument: Wrong answer
Falsy argument is treated differently from undefined: Wrong answer

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