JavaScript Tips — Print assertion failures to the developer console using console.assert

console.assert prints an error message to the #JavaScript developer console when a given condition fails The first argument to console.assert is the condition to test. If the condition is true, nothing is printed. If the condition evaluates to false, then the assertion as failed and an error is printed. Any additional arguments to console.assert are also printed to the developer console when the assertion fails https://developer.mozilla.org/en-US/docs/Web/API/Console/assert