mid-level-programmer-litmus-test.md

Can you convert a Value Object (i.e. JSON) to YAML?

My Expectation

My expectation is that a mid-senior level developer should be able to accomplish this task in under 4 hours:

• write a basic solution in 30-60 minutes
• debug / test / fine-tune for another 60-90 minutes
• document, package, and publish within the remaining time

I could see it reasonable even if a developer takes 2 days to solve this for the first time - possibly because they needed to take a break but didn't, such as feeling pressure and getting brain freeze, taking an initial wrong approach, over-thinking the problem, and then just keeping beating the dead horse, etc - especially if they've never had to work independently before.

However, the general rule is 4 hours. Otherwise, I don't think they're a good hire for jobs that require any sort of data or API manipulation.

Problem Description

Given a Value Object that looks like this:
(in JavaScript)

var data = {
  foo: [
    {
      bar: [
        {
          baz: ["apples", "bananas"],
        },
      ],
      quux: [
        {
          do: ["red thing", "blue thing"],
        },
      ],
    },
  ],
  grault: {
    name: "Bob",
    age: 37,
    grumpy: false,
    nullish: null,
  },
  answer: 42,
};

Can you produce a function that outputs it as YAML?

foo:
  - bar:
      - baz:
          - "apples"
          - "bananas"
    quux:
      - do:
          - "red thing"
          - "blue thing"
grault:
  name: "Bob"
  age: 37
  grumpy: false
  nullish: null
answer: 42

The solution could have multiple functions, or be recursive, or be iterative. It should not use any libraries.