implement new Validator interface and new CEP validator

cep.go

@@ -0,0 +1,38 @@
+package brazil
+
+import (
+	"fmt"
+	"math/rand"
+	"regexp"
+	"strconv"
+	"time"
+)
+
+// NewCEPValidator creates a CEP number validator, containing inner mask and validation functions which can be
+// accessed via Mask and Validate methods.
+func NewCEPValidator() Validator {
+	return &validator{
+		maskFunc: func(value string) string {
+			value = onlyDigits(value)
+
+			return fmt.Sprintf("%s-%s", value[:5], value[5:])
+		},
+		validationFunc: func(value string) error {
+			value = onlyDigits(value)
+
+			if !regexp.MustCompile(`^\d{8}$`).MatchString(value) {
+				return ErrInvalidCEPFormat
+			}
+
+			return nil
+		},
+	}
+}
+
+// RandomCEPNumber generates a random valid CEP number
+func RandomCEPNumber() string {
+	seed := time.Now().UnixNano()
+	source := rand.NewSource(seed)
+	r := rand.New(source)
+	return strconv.Itoa(r.Intn(89999999) + 10000000)
+}

cep_test.go

@@ -0,0 +1,32 @@
+package brazil_test
+
+import (
+	"testing"
+
+	. "github.com/flavioltonon/go-brazil"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCEP(t *testing.T) {
+	c := NewCEPValidator()
+
+	t.Run("When parsing a CEP with an valid number, no errors should be returned and cep should contain a value", func(t *testing.T) {
+		assert.NoError(t, c.Validate("12345-678"))
+	})
+
+	t.Run("When parsing a CEP with an valid masked number, no errors should be returned and cep should contain a value", func(t *testing.T) {
+		assert.NoError(t, c.Validate("12345678"))
+	})
+
+	t.Run("When parsing a CEP with an invalid input number, an ErrInvalidCEPFormat should be returned and cep should be nil", func(t *testing.T) {
+		assert.Error(t, c.Validate("123456789"), ErrInvalidCEPFormat)
+	})
+
+	t.Run("When a random CEP number is generated, it should be successfully validated", func(t *testing.T) {
+		for i := 0; i < 1000; i++ {
+			value := RandomCEPNumber()
+			assert.NoError(t, c.Validate(value))
+		}
+	})
+}

errors.go

@@ -21,6 +21,9 @@ var (
 	ErrIncorrectLenghtPISNumber = errors.New("PIS numbers must contain 11 or 13 numbers")
 	ErrInvalidPISNumber         = errors.New("PIS number input is not valid")
 
+	ErrInvalidCEPFormat = errors.New("CEP format input is different than expected. Expected format: XXXXX-XXX, XXXXXXXX (e.g. 12345-678, 12345678)")
+	ErrInvalidCEPLength = errors.New("CEP numbers must contain 9 digits")
+
 	ErrIncorrectFormatDate = errors.New("Date format input is different than expected. Expected format: DD/MM/YYYY")
 	ErrInvalidYearLimits   = errors.New("Date minYear must be lower than maxYear and higher than zero")
 	ErrNotPastDate         = errors.New("Date must be in the past")

go.mod

@@ -2,4 +2,7 @@ module github.com/flavioltonon/go-brazil
 
 go 1.13
 
-require github.com/smartystreets/goconvey v1.6.4
+require (
+	github.com/smartystreets/goconvey v1.6.4
+	github.com/stretchr/testify v1.6.1
+)

go.sum

@@ -1,13 +1,24 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 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=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
 github.com/smartystreets/goconvey v1.6.4 h1:fv0U8FUIMPNf1L9lnHLvLhgicrIVChEkdzIKYqbNC9s=
 github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

utils.go

@@ -0,0 +1,27 @@
+package brazil
+
+import "unicode"
+
+func onlyDigits(input string) string {
+	norm := make([]rune, 0)
+
+	for _, r := range input {
+		if unicode.IsDigit(r) {
+			norm = append(norm, r)
+		}
+	}
+
+	return string(norm)
+}
+
+func onlyLetters(input string) string {
+	norm := make([]rune, 0)
+
+	for _, r := range input {
+		if unicode.IsLetter(r) {
+			norm = append(norm, r)
+		}
+	}
+
+	return string(norm)
+}

validator.go

@@ -0,0 +1,29 @@
+package brazil
+
+type Validator interface {
+	Validate(value string) error
+}
+
+type Maskable interface {
+	Mask(value string) string
+}
+
+type MaskableValidator interface {
+	Maskable
+	Validator
+}
+
+type validator struct {
+	maskFunc       func(value string) string
+	validationFunc func(value string) error
+}
+
+// Validate checks if the input value is valid according to the validator rules and returns an error if it isn't.
+func (v *validator) Validate(value string) error {
+	return v.validationFunc(value)
+}
+
+// Mask applies the validator mask to a value. If the value is not valid, the masking may not be completely correct and the method may panic.
+func (v *validator) Mask(value string) string {
+	return v.maskFunc(value)
+}