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I am trying to flatten an array within an array without using .concat or .reduce().
For example:
input: [1, [2, [[3, 4], 5], 6]]
output: [1, 2, 3, 4, 5, 6]
So here's my code: https://jsfiddle.net/4wn5qc0b/1/
I honestly don't trust the result I see in console.log, so I'd like to use assert.de...