Cash Register project needs a better description on what to expect

[apraditya]

I think there are 2 tests that have conflicting assertions. Like the following test (the 3rd)

checkCashRegister(3.26, 100, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]])
should return {status: "OPEN", change: [["TWENTY", 60], ["TEN", 20], ["FIVE", 15], ["ONE", 1], ["QUARTER", 0.5], ["DIME", 0.2], ["PENNY", 0.04]]}

which to my understanding, the test reads given the cid containing all the currency units, the function should return the change with array of non-zero currency unit. As you can see, there’s no ["ONE HUNDRED", 0].

Where as this test (the last one),

checkCashRegister(19.5, 20, [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])
should return {status: "CLOSED", change: [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]}

the function is expected to return the change with all the currency units.

The issue I have is when I fixed the first one test, it breaks the other and vice versa. Therefore, the questions are:

1. How do you combine these 2 tests into a better description on what is expected value of change to return?
2. What are each tests are trying to prove?

So with better description I can refactor my function accordingly.

Here’s the code I have so far.

function checkCashRegister(price, cash, cid) {
var changeAmount = cash - price;
const unitDef = {
  'ONE HUNDRED': 100,
  TWENTY: 20,
  TEN: 10,
  FIVE: 5,
  ONE: 1,
  QUARTER: 0.25,
  DIME: 0.1,
  NICKEL: 0.05,
  PENNY: 0.01
};
var changes = [];


Object
  .keys(unitDef)
  .forEach((unit) => {
    let totalUnitChange = 0
    let cidPair = cid.find(([unitName, _totalUnit]) => unitName == unit);
    let availableUnit = cidPair[1]

    if (changeAmount < unitDef[unit]) {
      if (availableUnit == 0) {
        changes.push([unit, 0])
      }
      return;
    }
    
    while (changeAmount >= unitDef[unit] && totalUnitChange < availableUnit) {
      changeAmount = parseFloat((changeAmount - unitDef[unit]).toFixed(2));
      totalUnitChange = parseFloat((totalUnitChange + unitDef[unit]).toFixed(2));
    }

    changes.push([unit, totalUnitChange]);

    if (totalUnitChange > 0) {
      cidPair[1] -= totalUnitChange
    }
  });

if (changeAmount > 0) {
  return {
    status: 'INSUFFICIENT_FUNDS',
    change: []
  };
}

var result = {}
if (changes.length > 0) {
  if (cid.every(([_unitName, totalUnit]) => totalUnit === 0)) {
    result.status = 'CLOSED';
  } else {
    result.status = 'OPEN';
  }

  result.change = changes
}

return result;
}

checkCashRegister(19.5, 20, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]);

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Challenge: Cash Register

Link to the challenge:

freeCodeCamp.org

[sanity]

You are assuming those two cases are essentially the same, just with different status. They are not. When status is OPEN change indicates what is supposed to be paid out from the drawer. With CLOSED status, change indicates what is in the drawer.

[ilenia]

@apraditya

the function is expected to return the change with all the currency units.

This is the requirement here:

Return {status: "CLOSED", change: [...]} with cash-in-drawer as the value for the key change if it is equal to the change due.

It says to just return the cid as is.

@apraditya

which to my understanding, the test reads given the cid containing all the currency units, the function should return the change with array of non-zero currency unit . As you can see, there’s no ["ONE HUNDRED", 0] .

Otherwise, return {status: "OPEN", change: [...]} , with the change due in coins and bills, sorted in highest to lowest order, as the value of the change key.

Here no ONE HUNDRED because you don’t have to give a ONE HUNDRED bill back as change.

There is an issue open about the description of this project, so if you want you can add your comment here:

Cash Register Challenge - Remove ambiguities

[apraditya]

Thank you @ilenia! It really helps my understanding. I’ll definitely look at the GH issue and join the discussion there.