table_driven_doughnuts_box_table_tests.go

package doughnuts_box

import (
    "testing"

    "github.com/stretchr/testify/assert"
    "github.com/stretchr/testify/require"
)

func TestPackDoughnutsBoxTableTests(t *testing.T) {
    // Anonymous struct of test cases
    tests := []struct {
        name                           string
        boxCapacity                    int
        errorExpected                  bool
        errorMessage                   string
        items                          []string
        expectedNumOfDoughnutsInTheBox int
    }{
        {
            name:                           "Filling the box with tasty doughnuts",
            boxCapacity:                    4,
            errorExpected:                  false,
            errorMessage:                   "",
            items:                          []string{"Sri Lankan Cinnamon Sugar", "Matcha Tea", "Home Made Raspberry Jam", "Lime & Coconut (ve)"},
            expectedNumOfDoughnutsInTheBox: 4,
        },
        {
            name:                           "Attempt to fill the box with too many doughnuts",
            boxCapacity:                    4,
            errorExpected:                  true,
            errorMessage:                   "failed to put 5 doughnuts in the box, it's only has 4 doughnuts capacity",
            items:                          []string{"Sri Lankan Cinnamon Sugar", "Matcha Tea", "Home Made Raspberry Jam", "Lime & Coconut (ve)", "Lime & Coconut (ve)"},
            expectedNumOfDoughnutsInTheBox: 0,
        },
        {
            name:                           "Attempt to put a giant chocolate cookie into the box",
            boxCapacity:                    2,
            errorExpected:                  true,
            errorMessage:                   "the following items cannot be placed into the box: [Giant Chocolate Cookie]",
            items:                          []string{"Sri Lankan Cinnamon Sugar", "Giant Chocolate Cookie"},
            expectedNumOfDoughnutsInTheBox: 1,
        },
    }

    for _, tc := range tests {
        // each test case from  table above run as a subtest
        t.Run(tc.name, func(t *testing.T) {
            // Arrange
            box := newDoughnutsBox(tc.boxCapacity)

            // Act
            numOfDoughnutsInTheBox, err := box.pack(tc.items)

            // Assert
            if tc.errorExpected {
                require.Error(t, err)
                assert.Equal(t, tc.errorMessage, err.Error())
            }
            assert.Equal(t, tc.expectedNumOfDoughnutsInTheBox, numOfDoughnutsInTheBox)
        })
    }
}