Refactor

Makefile

@@ -0,0 +1,6 @@
+test:
+	go test -count=2 .
+
+coverage:
+	go test -coverprofile=coverage.out .
+	go tool cover -html=coverage.out

creditcard.go

@@ -1,10 +1,8 @@
-// Package creditcard provides methods for validating credit cards
 package creditcard
 
 import (
 	"errors"
 	"strconv"
-	"time"
 )
 
 // Card holds generic information about the credit card
@@ -99,9 +97,10 @@ func (c *Card) Validate(allowTestNumbers ...bool) error {
 func (c *Card) ValidateExpiration() error {
 	var year, month int
 	var err error
+	timeNow := timeNowCaller()
 
 	if len(c.Year) < 3 {
-		year, err = strconv.Atoi(strconv.Itoa(time.Now().UTC().Year())[:2] + c.Year)
+		year, err = strconv.Atoi(strconv.Itoa(timeNow.UTC().Year())[:2] + c.Year)
 		if err != nil {
 			return errors.New("Invalid year")
 		}
@@ -121,11 +120,11 @@ func (c *Card) ValidateExpiration() error {
 		return errors.New("Invalid month")
 	}
 
-	if year < time.Now().UTC().Year() {
+	if year < timeNowCaller().UTC().Year() {
 		return errors.New("Credit card has expired")
 	}
 
-	if year == time.Now().UTC().Year() && month < int(time.Now().UTC().Month()) {
+	if year == timeNowCaller().UTC().Year() && month < int(timeNowCaller().UTC().Month()) {
 		return errors.New("Credit card has expired")
 	}
 
@@ -170,62 +169,46 @@ func (c *Card) MethodValidate() (Company, error) {
 	}
 
 	switch {
-	case ccDigits.At(2) == 34 || ccDigits.At(2) == 37:
+	case isAmex(ccDigits):
 		return Company{"amex", "American Express"}, nil
-	case ccDigits.At(4) == 5610 || (ccDigits.At(6) >= 560221 && ccDigits.At(6) <= 560225):
+	case isBankCard(ccDigits):
 		return Company{"bankcard", "Bankcard"}, nil
-	case ccDigits.At(6) == 604400 || ccDigits.At(6) == 627170 || ccDigits.At(6) == 603522 || ccDigits.At(6) == 589657 || (ccDigits.At(6) >= 604201 && ccDigits.At(6) <= 604219) || (ccDigits.At(6) >= 604300 && ccDigits.At(6) <= 604399):
+	case isCabal(ccDigits):
 		return Company{"cabal", "Cabal"}, nil
-	case ccDigits.At(2) == 62 || ccDigits.At(2) == 81:
+	case isUnionPay(ccDigits):
 		return Company{"china unionpay", "China UnionPay"}, nil
-	case ccDigits.At(3) >= 300 && ccDigits.At(3) <= 305 && ccLen == 15:
+	case isDinersClubCarteBlance(ccDigits, ccLen):
 		return Company{"diners club carte blanche", "Diners Club Carte Blanche"}, nil
-	case ccDigits.At(4) == 2014 || ccDigits.At(4) == 2149:
+	case isDinersClubEnroute(ccDigits):
 		return Company{"diners club enroute", "Diners Club enRoute"}, nil
-	case ((ccDigits.At(3) >= 300 && ccDigits.At(3) <= 305) || ccDigits.At(3) == 309 || ccDigits.At(2) == 36 || ccDigits.At(2) == 38 || ccDigits.At(2) == 39) && ccLen <= 14:
+	case isDinersClubInternational(ccDigits, ccLen):
 		return Company{"diners club international", "Diners Club International"}, nil
-	case ccDigits.At(4) == 6011 || (ccDigits.At(6) >= 622126 && ccDigits.At(6) <= 622925) || (ccDigits.At(3) >= 644 && ccDigits.At(3) <= 649) || ccDigits.At(2) == 65:
+	case isDiscover(ccDigits):
 		return Company{"discover", "Discover"}, nil
 	// Elo must be checked before interpayment
-	case ccDigits.At(4) == 4011 || ccDigits.At(6) == 431274 || ccDigits.At(6) == 438935 ||
-		ccDigits.At(6) == 451416 || ccDigits.At(6) == 457393 || ccDigits.At(4) == 4576 ||
-		ccDigits.At(6) == 457631 || ccDigits.At(6) == 457632 || ccDigits.At(6) == 504175 ||
-		ccDigits.At(6) == 627780 || ccDigits.At(6) == 636297 || ccDigits.At(6) == 636368 ||
-		ccDigits.At(6) == 636369 || (ccDigits.At(6) >= 506699 && ccDigits.At(6) <= 506778) ||
-		(ccDigits.At(6) >= 509000 && ccDigits.At(6) <= 509999) ||
-		(ccDigits.At(6) >= 650031 && ccDigits.At(6) <= 650051) ||
-		(ccDigits.At(6) >= 650035 && ccDigits.At(6) <= 650033) ||
-		(ccDigits.At(6) >= 650405 && ccDigits.At(6) <= 650439) ||
-		(ccDigits.At(6) >= 650485 && ccDigits.At(6) <= 650538) ||
-		(ccDigits.At(6) >= 650541 && ccDigits.At(6) <= 650598) ||
-		(ccDigits.At(6) >= 650700 && ccDigits.At(6) <= 650718) ||
-		(ccDigits.At(6) >= 650720 && ccDigits.At(6) <= 650727) ||
-		(ccDigits.At(6) >= 650901 && ccDigits.At(6) <= 650920) ||
-		(ccDigits.At(6) >= 651652 && ccDigits.At(6) <= 651679) ||
-		(ccDigits.At(6) >= 655000 && ccDigits.At(6) <= 655019) ||
-		(ccDigits.At(6) >= 655021 && ccDigits.At(6) <= 655021):
+	case isElo(ccDigits):
 		return Company{"elo", "Elo"}, nil
-	case matchesValue(ccDigits.At(6), []int{606282, 637095, 637568, 637599, 637609, 637612}):
+	case isHipercard(ccDigits):
 		return Company{"hipercard", "Hipercard"}, nil
-	case ccDigits.At(3) == 636 && ccLen >= 16 && ccLen <= 19:
+	case isInterpayment(ccDigits, ccLen):
 		return Company{"interpayment", "InterPayment"}, nil
-	case ccDigits.At(3) >= 637 && ccDigits.At(3) <= 639 && ccLen == 16:
+	case isInstapayment(ccDigits, ccLen):
 		return Company{"instapayment", "InstaPayment"}, nil
-	case ccDigits.At(4) >= 3528 && ccDigits.At(4) <= 3589:
+	case isJCB(ccDigits):
 		return Company{"jcb", "JCB"}, nil
-	case ccDigits.At(6) == 589562:
+	case isNaranja(ccDigits):
 		return Company{"naranja", "Naranja"}, nil
-	case ccDigits.At(4) == 5018 || ccDigits.At(4) == 5020 || ccDigits.At(4) == 5038 || ccDigits.At(4) == 5612 || ccDigits.At(4) == 5893 || ccDigits.At(4) == 6304 || ccDigits.At(4) == 6759 || ccDigits.At(4) == 6761 || ccDigits.At(4) == 6762 || ccDigits.At(4) == 6763 || c.Number[:3] == "0604" || ccDigits.At(4) == 6390:
+	case isMaestro(c, ccDigits):
 		return Company{"maestro", "Maestro"}, nil
-	case ccDigits.At(4) == 5019:
+	case isDankort(ccDigits):
 		return Company{"dankort", "Dankort"}, nil
-	case ccDigits.At(2) >= 51 && ccDigits.At(2) <= 55 || ccDigits.At(6) >= 222100 && ccDigits.At(6) <= 272099:
+	case isMasterCard(ccDigits):
 		return Company{"mastercard", "MasterCard"}, nil
-	case ccDigits.At(4) == 4026 || ccDigits.At(6) == 417500 || ccDigits.At(4) == 4405 || ccDigits.At(4) == 4508 || ccDigits.At(4) == 4844 || ccDigits.At(4) == 4913 || ccDigits.At(4) == 4917:
+	case isVisaElectron(ccDigits):
 		return Company{"visa electron", "Visa Electron"}, nil
-	case ccDigits.At(1) == 4:
+	case isVisa(ccDigits):
 		return Company{"visa", "Visa"}, nil
-	case ccDigits.At(2) == 50:
+	case isAura(ccDigits):
 		return Company{"aura", "Aura"}, nil
 	default:
 		return Company{"", ""}, errors.New("Unknown credit card method")
@@ -271,3 +254,7 @@ func matchesValue(number int, numbers []int) bool {
 	}
 	return false
 }
+
+func isInBetween(n, min, max int) bool {
+	return n >= min && n <= max
+}

creditcard_test.go

@@ -1,10 +1,11 @@
 package creditcard
 
 import (
-	. "github.com/smartystreets/goconvey/convey"
 	"strconv"
 	"testing"
 	"time"
+
+	. "github.com/smartystreets/goconvey/convey"
 )
 
 func TestFourDigits(t *testing.T) {
@@ -466,3 +467,17 @@ func TestMethod(t *testing.T) {
 		})
 	})
 }
+
+func TestCard_ValidateExpiration(t *testing.T) {
+	Convey("should get an error if card year is current year and card month is before current month", t, func() {
+		defer resetMocks()
+		timeNowCaller = func() time.Time {
+			return time.Date(2001, 3, 1, 1, 1, 1, 1, time.UTC)
+		}
+		card := Card{Number: "4012888888881881", Cvv: "111", Month: "02", Year: "2001"}
+
+		err := card.ValidateExpiration()
+		So(err, ShouldNotBeNil)
+		So(err.Error(), ShouldEqual, "Credit card has expired")
+	})
+}

go.mod

@@ -1,5 +1,11 @@
 module github.com/durango/go-credit-card
 
-go 1.13
+go 1.17
 
 require github.com/smartystreets/goconvey v1.6.4
+
+require (
+	github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 // indirect
+	github.com/jtolds/gls v4.20.0+incompatible // indirect
+	github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d // indirect
+)

go.sum

@@ -1,3 +1,4 @@
+github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=
 github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=

main.go

@@ -0,0 +1,10 @@
+// Package creditcard provides methods for validating credit cards
+package creditcard
+
+import "time"
+
+var timeNowCaller = time.Now
+
+func resetMocks() {
+	timeNowCaller = time.Now
+}

validator.go

@@ -0,0 +1,109 @@
+package creditcard
+
+func isAmex(ccDigits digits) bool {
+	return matchesValue(ccDigits.At(2), []int{34, 37})
+}
+
+func isBankCard(ccDigits digits) bool {
+	return ccDigits.At(4) == 5610 || isInBetween(ccDigits.At(6), 560221, 560225)
+}
+
+func isCabal(ccDigits digits) bool {
+	atSix := ccDigits.At(6)
+
+	return matchesValue(atSix, []int{604400, 627170, 603522, 589657}) ||
+		isInBetween(atSix, 604201, 604219) ||
+		isInBetween(atSix, 604300, 604399)
+}
+
+func isUnionPay(ccDigits digits) bool {
+	return matchesValue(ccDigits.At(2), []int{62, 81})
+}
+
+func isDinersClubCarteBlance(ccDigits digits, ccLen int) bool {
+	return isInBetween(ccDigits.At(3), 300, 305) && ccLen == 15
+}
+
+func isDinersClubEnroute(ccDigits digits) bool {
+	return matchesValue(ccDigits.At(4), []int{2014, 2149})
+}
+
+func isDinersClubInternational(ccDigits digits, ccLen int) bool {
+	checkThree := isInBetween(ccDigits.At(3), 300, 305) || ccDigits.At(3) == 309
+	checkTwoo := matchesValue(ccDigits.At(2), []int{36, 38, 39})
+
+	return (checkThree || checkTwoo) && ccLen <= 14
+}
+
+func isDiscover(ccDigits digits) bool {
+	return ccDigits.At(4) == 6011 ||
+		isInBetween(ccDigits.At(6), 622126, 622925) ||
+		isInBetween(ccDigits.At(3), 644, 649) ||
+		ccDigits.At(2) == 65
+}
+
+func isElo(ccDigits digits) bool {
+	atFour := ccDigits.At(4)
+	atSix := ccDigits.At(6)
+
+	return matchesValue(atFour, []int{4011, 4576}) ||
+		matchesValue(atSix, []int{431274, 438935, 451416, 457393, 457631, 457632, 504175, 627780, 636297, 636368, 636369}) ||
+		isInBetween(atSix, 506699, 506778) ||
+		isInBetween(atSix, 509000, 509999) ||
+		isInBetween(atSix, 650031, 650051) ||
+		isInBetween(atSix, 650035, 650033) ||
+		isInBetween(atSix, 650405, 650439) ||
+		isInBetween(atSix, 650485, 650538) ||
+		isInBetween(atSix, 650541, 650598) ||
+		isInBetween(atSix, 650700, 650718) ||
+		isInBetween(atSix, 650720, 650727) ||
+		isInBetween(atSix, 650901, 650920) ||
+		isInBetween(atSix, 651652, 651679) ||
+		isInBetween(atSix, 655000, 655019) ||
+		isInBetween(atSix, 655021, 655021)
+}
+
+func isHipercard(ccDigits digits) bool {
+	return matchesValue(ccDigits.At(6), []int{606282, 637095, 637568, 637599, 637609, 637612})
+}
+
+func isInterpayment(ccDigits digits, ccLen int) bool {
+	return ccDigits.At(3) == 636 && isInBetween(ccLen, 16, 19)
+}
+
+func isInstapayment(ccDigits digits, ccLen int) bool {
+	return isInBetween(ccDigits.At(3), 637, 639) && ccLen == 16
+}
+
+func isJCB(ccDigits digits) bool {
+	return isInBetween(ccDigits.At(4), 3528, 3589)
+}
+
+func isNaranja(ccDigits digits) bool {
+	return ccDigits.At(6) == 589562
+}
+
+func isMaestro(c *Card, ccDigits digits) bool {
+	return matchesValue(ccDigits.At(4), []int{5018, 5020, 5038, 5612, 5893, 6304, 6759, 6761, 6762, 6763, 6390}) ||
+		c.Number[:3] == "0604"
+}
+
+func isDankort(ccDigits digits) bool {
+	return ccDigits.At(4) == 5019
+}
+
+func isMasterCard(ccDigits digits) bool {
+	return isInBetween(ccDigits.At(2), 51, 55) || isInBetween(ccDigits.At(6), 222100, 272099)
+}
+
+func isVisaElectron(ccDigits digits) bool {
+	return matchesValue(ccDigits.At(4), []int{4026, 4405, 4508, 4844, 4913, 4917}) || ccDigits.At(6) == 417500
+}
+
+func isVisa(ccDigits digits) bool {
+	return ccDigits.At(1) == 4
+}
+
+func isAura(ccDigits digits) bool {
+	return ccDigits.At(2) == 50
+}