Discussion on: Daily Challenge #49 - Dollars and Cents

[Donald Feury]

Go - with tests as usual

fun fact - this was the first time I wrote anything using Vim

dollars.go

package dollars

import (
    "fmt"
)

// Dollars returns the string representation of a float as a dollar amount
func Dollars(amount float64) string {
    return fmt.Sprintf("$%.2f", amount)
}

dollars_test.go

package dollars

import (
    "testing"
)

var testCases = []struct {
    description string
    input       float64
    expected    string
}{
    {
        "only cents",
        .04,
        "$0.04",
    },
    {
        "only dollars",
        3,
        "$3.00",
    },
    {
        "cents & dollars",
        3.14,
        "$3.14",
    },
    {
        "amounts with more than two decimal places round to the nearest cent",
        4.478,
        "$4.48",
    },

}

func TestDollars(t *testing.T) {
    for _, test := range testCases {
        if result := Dollars(test.input); result != test.expected {
            t.Fatalf("FAILED: %s - Dollars(%f): %s, expected %s \n", test.description, test.input, result, test.expected)
        }
        t.Logf("PASS: %s \n", test.description)
    }
}

[Tiash]

I'm not sure, but I think that "Sprintf" rounds to nearest integer.
Try with a value like 3.149 if still returns 3.14 or 3.15

[Donald Feury]

Added additional test case to clarify current rounding behavior.

[Donald Feury]

Yeah it rounds to the nearest cent in this case, the question becomes then do we want it to work that way, or do we say "Hey you don't have a full cent" so it always rounds down?