TDD Workshop

range.go

package myrange

import "fmt"

type RangeType int

const (
	OPEN RangeType = iota
	CLOSE
	OPEN_CLOSE
	CLOSE_OPEN
)

type Range struct {
	LowerEndpoint int
	UpperEndpoint int
	RangeType     RangeType
}

func NewRange(lower int, upper int, rangeType RangeType) (*Range, error) {
	if rangeType == CLOSE && lower > upper {
		return nil, fmt.Errorf("rangeType == CLOSE && lower > upper")
	}
	if rangeType == OPEN && lower >= upper {
		return nil, fmt.Errorf("rangeType == OPEN && lower >= upper")
	}
	return &Range{lower, upper, rangeType}, nil
}

func (r *Range) Include(in *Range) bool {
	if r.LowerEndpoint <= in.LowerEndpoint && r.UpperEndpoint >= in.UpperEndpoint {
		return true
	}
	return false
}

test_range.go

package myrange

import "testing"

var propertyTest = []struct {
	lower     int
	upper     int
	rangeType RangeType
	out       *Range
}{
	{1, 2, OPEN, &Range{1, 2, OPEN}},
	{2, 2, OPEN, nil},
	{2, 1, OPEN, nil},
	{1, 2, CLOSE, &Range{1, 2, CLOSE}},
	{2, 2, CLOSE, &Range{2, 2, CLOSE}},
	{2, 1, CLOSE, nil},
}

func TestNewRange(t *testing.T) {
	for _, tt := range propertyTest {
		r, _ := NewRange(tt.lower, tt.upper, tt.rangeType)
		if tt.out == nil {
			if r != nil {
				t.Errorf("expect:%v result:%v", tt, r)
			}
		} else {
			if *r != *tt.out {
				t.Errorf("expect:%v result:%v", tt, r)
			}
		}
	}
}

var includeTest = []struct {
	in1 *Range
	in2 *Range
	out bool
}{
	{&Range{1, 10, CLOSE}, &Range{2, 9, CLOSE}, true},
	{&Range{1, 10, CLOSE}, &Range{1, 10, CLOSE}, true},
	{&Range{1, 10, CLOSE}, &Range{2, 11, CLOSE}, false},
	{&Range{1, 10, CLOSE}, &Range{0, 9, CLOSE}, false},
}

func TestInclude(t *testing.T) {
	for _, tt := range includeTest {
		if tt.in1.Include(tt.in2) != tt.out {
			t.Errorf("エラー")
		}
	}
}

cf.

• https://golang.org/pkg/testing/
• https://github.com/golang/go/wiki/TableDrivenTests