feat: UUID Generator

.gitignore

@@ -10,6 +10,8 @@
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
 cover.html
+.vscode/
+
 
 # Project-local glide cache, RE: https://github.com/Masterminds/glide/issues/736
 .glide/

README.md

@@ -93,6 +93,10 @@ Supported tag:
 * Amount
 * Amount with Currency
 
+**UUID :**
+* UUID Digit (32 bytes)
+* UUID Hyphenated (36 bytes)
+
 **Skip :**
 * \-
 
@@ -146,6 +150,8 @@ type SomeStruct struct {
 	Currency           string  `faker:"currency"`
 	Amount             float64 `faker:"amount"`
 	AmountWithCurrency string  `faker:"amount_with_currency"`
+	UUIDHypenated	   string  `faker:"uuid_hyphenated"`
+	UUID	           string  `faker:"uuid_digit"`
 	Skip		   string  `faker:"-"`
 }
 
@@ -198,6 +204,8 @@ func main() {
 			Currency: IRR,
 			Amount: 88.990000,
 			AmountWithCurrency: XBB 49257.100000,
+			UUIDHypenated: 8f8e4463-9560-4a38-9b0c-ef24481e4e27,
+			UUID: 90ea6479fd0e4940af741f0a87596b73,
 			Skip:
 		}
 	*/

faker.go

@@ -20,6 +20,8 @@ const (
 	letterIdxMax       = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
 	letterBytes        = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 	tagName            = "faker"
+	ID                 = "uuid_digit"
+	HyphenatedID       = "uuid_hyphenated"
 	Email              = "email"
 	MacAddress         = "mac_address"
 	DomainName         = "domain_name"
@@ -102,6 +104,8 @@ var mapperTag = map[string]interface{}{
 	Currency:           GetPrice().Currency,
 	Amount:             GetPrice().Amount,
 	AmountWithCurrency: GetPrice().AmountWithCurrency,
+	ID:                 GetIdentifier().Digit,
+	HyphenatedID:       GetIdentifier().Hyphenated,
 }
 
 // Generic Error Messages for tags

faker_test.go

@@ -49,6 +49,8 @@ type SomeStruct struct {
 	Currency           string  `faker:"currency"`
 	Amount             float64 `faker:"amount"`
 	AmountWithCurrency string  `faker:"amount_with_currency"`
+	ID                 string  `faker:"uuid_digit"`
+	HyphenatedID       string  `faker:"uuid_hyphenated"`
 
 	MapStringString        map[string]string
 	MapStringStruct        map[string]AStruct
@@ -107,6 +109,8 @@ type TaggedStruct struct {
 	Currency           string  `faker:"currency"`
 	Amount             float32 `faker:"amount"`
 	AmountWithCurrency string  `faker:"amount_with_currency"`
+	ID                 string  `faker:"uuid_digit"`
+	HyphenatedID       string  `faker:"uuid_hyphenated"`
 }
 
 func (t TaggedStruct) String() string {
@@ -149,6 +153,8 @@ func (t TaggedStruct) String() string {
 	Currency: %s,
 	Amount: %f,
 	AmountWithCurrency: %s,
+	HyphenatedID: %s,
+	ID: %s,
 }`, t.Latitude, t.Longitude, t.CreditCardNumber,
 		t.CreditCardType, t.Email, t.IPV4,
 		t.IPV6, t.Password, t.PhoneNumber, t.MacAddress,
@@ -160,6 +166,7 @@ func (t TaggedStruct) String() string {
 		t.DayOfMonth, t.Timestamp, t.Century, t.TimeZone,
 		t.TimePeriod, t.Word, t.Sentence, t.Paragraph,
 		t.Currency, t.Amount, t.AmountWithCurrency,
+		t.HyphenatedID, t.ID,
 	)
 }
 

uuid.go

@@ -0,0 +1,54 @@
+package faker
+
+import (
+	"crypto/rand"
+	"fmt"
+	"io"
+)
+
+var identifier Identifier
+
+// GetIdentifier returns a new Identifier
+func GetIdentifier() Identifier {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if identifier == nil {
+		identifier = &UUID{}
+	}
+	return identifier
+}
+
+// Identifier ...
+type Identifier interface {
+	Digit() string
+	Hyphenated() string
+}
+
+// UUID struct
+type UUID struct{}
+
+// createUUID returns a 16 byte slice with random values
+func createUUID() []byte {
+	b := make([]byte, 16)
+	io.ReadFull(rand.Reader, b)
+	// variant bits; see section 4.1.1
+	b[8] = b[8]&^0xc0 | 0x80
+	// version 4 (pseudo-random); see section 4.1.3
+	b[6] = b[6]&^0xf0 | 0x40
+	return b
+}
+
+// Hyphenated returns a 36 byte hyphenated UUID
+func (i UUID) Hyphenated() string {
+	b := createUUID()
+	uuid := fmt.Sprintf("%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])
+	return uuid
+}
+
+// Digit returns a 32 bytes UUID
+func (i UUID) Digit() string {
+	b := createUUID()
+	uuid := fmt.Sprintf("%x", b)
+	return uuid
+}

uuid_test.go

@@ -0,0 +1,33 @@
+package faker
+
+import (
+	"fmt"
+	"regexp"
+	"testing"
+)
+
+func TestDigit(t *testing.T) {
+	p := GetIdentifier()
+	uuid := p.Digit()
+	if match, err := regexp.Match("^[a-zA-Z0-9]{32}$", []byte(uuid)); !match || err != nil {
+		t.Errorf("Could not match the UUID format, err: %+v, match: %+v", err, match)
+	}
+}
+
+func TestHyphenated(t *testing.T) {
+	p := GetIdentifier()
+	uuid := p.Hyphenated()
+	exp := "[a-zA-Z 0-9]"
+	pattern := fmt.Sprintf("^%s{8}-%s{4}-%s{4}-%s{4}-%s{12}$", exp, exp, exp, exp, exp)
+	if match, err := regexp.Match(pattern, []byte(uuid)); !match || err != nil {
+		t.Errorf("Could not match the UUID hyphenated format, err: %+v, match: %+v", err, match)
+	}
+
+}
+
+func TestGetIdentifier(t *testing.T) {
+	identifier := GetIdentifier()
+	if identifier == nil {
+		t.Fatalf("TestGetIdentifier failed because identifier was nil")
+	}
+}