feat: add UserAgent faker

faker.go

@@ -96,6 +96,7 @@ const (
 	RussianLastNameFemaleTag  = "russian_last_name_female"
 	BloodTypeTag              = "blood_type"
 	CountryInfoTag            = "country_info"
+	UserAgentTag              = "user_agent"
 )
 
 // PriorityTags define the priority order of the tag
@@ -105,6 +106,7 @@ var PriorityTags = []string{ID, HyphenatedID, EmailTag, MacAddressTag, DomainNam
 	NAME, ChineseFirstNameTag, ChineseLastNameTag, ChineseNameTag, GENDER, UnixTimeTag, DATE, TIME, MonthNameTag,
 	YEAR, DayOfWeekTag, DayOfMonthTag, TIMESTAMP, CENTURY, TIMEZONE, TimePeriodTag, WORD, SENTENCE, PARAGRAPH,
 	CurrencyTag, AmountTag, AmountWithCurrencyTag, SKIP, Length, SliceLength, Language, BoundaryStart, BoundaryEnd, ONEOF, BloodTypeTag,
+	UserAgentTag,
 }
 
 type mapperTagCustom struct {
@@ -187,11 +189,12 @@ func initDefaultTag() {
 	defaultTag.Store(RussianLastNameMaleTag, RussianLastNameMaleTag)
 	defaultTag.Store(RussianFirstNameFemaleTag, RussianFirstNameFemaleTag)
 	defaultTag.Store(RussianLastNameFemaleTag, RussianLastNameFemaleTag)
+	defaultTag.Store(UserAgentTag, UserAgentTag)
 }
 
 var mapperTag = mapperTagCustom{}
 
-func initMappertTagDefault() {
+func initMapperTagDefault() {
 	mapperTag.Store(CreditCardType, GetPayment().CreditCardType)
 	mapperTag.Store(CreditCardNumber, GetPayment().CreditCardNumber)
 	mapperTag.Store(CountryInfoTag, GetAddress().CountryInfo)
@@ -236,6 +239,7 @@ func initMappertTagDefault() {
 	mapperTag.Store(RussianLastNameMaleTag, GetPerson().RussianLastNameMale)
 	mapperTag.Store(RussianLastNameFemaleTag, GetPerson().RussianLastNameFemale)
 	mapperTag.Store(BloodTypeTag, GetBlood().BloodGroup)
+	mapperTag.Store(UserAgentTag, GetUserAgent().UserAgent)
 }
 
 // Compiled regexp
@@ -260,7 +264,7 @@ func init() {
 
 func init() {
 	initDefaultTag()
-	initMappertTagDefault()
+	initMapperTagDefault()
 }
 
 // ResetUnique is used to forget generated unique values.

faker_test.go

@@ -105,6 +105,7 @@ type SomeStruct struct {
 	Email                  string `faker:"email"`
 	IPV4                   string `faker:"ipv4"`
 	IPV6                   string `faker:"ipv6"`
+	UserAgent              string `faker:"user_agent"`
 	Bool                   bool
 	SString                []string
 	SInt                   []int
@@ -204,6 +205,7 @@ func (s SomeStruct) String() string {
 	Email: %v
 	IPV4: %v
 	IPV6: %v
+        UserAgent: %v
 	Bool: %v
 	SString: %v
 	SInt: %v
@@ -231,7 +233,7 @@ func (s SomeStruct) String() string {
 		s.UInt8, s.UInt16, s.UInt32, s.UInt64,
 		s.CountryInfo, s.Latitude, s.LATITUDE, s.RealAddress, s.Long, s.LONG,
 		s.StringValue, s.CreditCardType, s.CreditCardNumber,
-		s.Email, s.IPV4, s.IPV6, s.Bool, s.SString, s.SInt,
+		s.Email, s.IPV4, s.IPV6, s.UserAgent, s.Bool, s.SString, s.SInt,
 		s.SInt8, s.SInt16, s.SInt32, s.SInt64, s.SFloat32, s.SFloat64,
 		s.SBool, s.Struct, s.Time, s.Stime, s.Currency, s.Amount,
 		s.AmountWithCurrency, s.ID, s.HyphenatedID, s.BloodType, s.MapStringString,

user_agent.go

@@ -0,0 +1,190 @@
+package faker
+
+import (
+	"fmt"
+	"reflect"
+	"time"
+
+	"github.com/go-faker/faker/v4/pkg/interfaces"
+)
+
+var (
+	browserTypes          = []string{"chrome", "firefox", "internetExplorer", "msedge", "opera", "safari"}
+	windowsPlatformTokens = []string{"Windows NT 6.2", "Windows NT 6.1", "Windows NT 6.0", "Windows NT 5.2",
+		"Windows NT 5.1", "Windows NT 5.01", "Windows NT 5.0", "Windows NT 4.0", "Windows 98; Win 9x 4.90",
+		"Windows 98", "Windows 95", "Windows CE",
+	}
+	linuxProcessor = []string{"i686", "x86_64"}
+	macProcessor   = []string{"Intel", "PPC", "U; Intel", "U; PPC"}
+	// langCodes contains language codes extracted from https://gist.github.com/JamieMason/3748498.
+	langCodes = []string{"af-ZA", "ar-AE", "ar-BH", "ar-DZ", "ar-EG", "ar-IQ", "ar-JO", "ar-KW", "ar-LB", "ar-LY",
+		"ar-MA", "ar-OM", "ar-QA", "ar-SA", "ar-SY", "ar-TN", "ar-YE", "be-BY", "bg-BG", "ca-ES", "cs-CZ", "cy-GB",
+		"da-DK", "de-AT", "de-DE", "de-CH", "de-LI", "de-LU", "dv-MV", "el-GR", "en-AU", "en-BZ", "en-CA", "en-GB",
+		"en-IE", "en-JM", "en-NZ", "en-PH", "en-TT", "en-US", "en-ZA", "en-ZW", "es-AR", "es-BO", "es-CL", "es-CO",
+		"es-CR", "es-DO", "es-EC", "es-ES", "es-GT", "es-HN", "es-MX", "es-NI", "es-PA", "es-PE", "es-PR", "es-PY",
+		"es-SV", "es-UY", "es-VE", "et-EE", "eu-ES", "fa-IR", "fi-FI", "fo-FO", "fr-BE", "fr-CA", "fr-FR", "fr-CH",
+		"fr-LU", "fr-MC", "gl-ES", "gu-IN", "he-IL", "hi-IN", "hr-BA", "hr-HR", "hu-HU", "hy-AM", "id-ID", "is-IS",
+		"it-CH", "it-IT", "ja-JP", "ka-GE", "kk-KZ", "kn-IN", "ko-KR", "ky-KG", "lt-LT", "lv-LV", "mi-NZ", "mk-MK",
+		"mn-MN", "mr-IN", "ms-BN", "ms-MY", "mt-MT", "nb-NO", "nl-BE", "nl-NL", "nn-NO", "ns-ZA", "pa-IN", "pl-PL",
+		"pt-BR", "pt-PT", "ro-RO", "ru-RU", "sa-IN", "se-FI", "se-NO", "se-SE", "sk-SK", "sl-SI", "sq-AL", "sv-FI",
+		"sv-SE", "sw-KE", "ta-IN", "te-IN", "th-TH", "tn-ZA", "tr-TR", "tt-RU", "uk-UA", "ur-PK", "vi-VN", "xh-ZA",
+		"zh-CN", "zh-HK", "zh-MO", "zh-SG", "zh-TW", "zu-ZA",
+	}
+)
+
+func GetUserAgent() UserAgenter {
+	ua := &UserAgent{}
+	return ua
+}
+
+type UserAgenter interface {
+	UserAgent(v reflect.Value) (interface{}, error)
+}
+
+// UserAgent implements logic loosely based on https://fakerphp.org/formatters/user-agent/.
+type UserAgent struct{}
+
+func (ua UserAgent) UserAgent(reflect.Value) (interface{}, error) {
+	browserType := randomElementFromSliceString(browserTypes)
+	switch browserType {
+	case "chrome":
+		return ua.chrome(), nil
+	case "firefox":
+		return ua.firefox(), nil
+	case "internetExplorer":
+		return ua.internetExplorer(), nil
+	case "msedge":
+		return ua.msEdge(), nil
+	case "opera":
+		return ua.opera(), nil
+	case "safari":
+		return ua.safari(), nil
+	}
+	return nil, fmt.Errorf(`unknown browser type: "%s"`, browserType)
+}
+
+// chrome generates a user agent string that resembles Google Chrome.
+// Example: "Mozilla/5.0 (X11; Linux i686) AppleWebKit/532.2 (KHTML, like Gecko) Chrome/69.0.3460.334 Safari/532.2"
+func (ua UserAgent) chrome() string {
+	chromeVer := fmt.Sprintf("%d.0.%d.%d",
+		ua.intBetween(36, 127), ua.intBetween(0, 6000), ua.intBetween(0, 400),
+	)
+	platformToken := randomElementFromSliceString([]string{
+		ua.linuxPlatformToken(),
+		ua.macPlatformToken("_"),
+		ua.windowsPlatformToken(),
+	})
+	safariType := randomElementFromSliceString([]string{"Safari", "Mobile Safari"})
+	webKitVer := ua.webKitVersion(false)
+	return fmt.Sprintf("Mozilla/5.0 (%s) AppleWebKit/%s (KHTML, like Gecko) Chrome/%s %s/%s",
+		platformToken, webKitVer, chromeVer, safariType, webKitVer,
+	)
+}
+
+// firefox generates a user agent string that resembles Firefox.
+// Example: "Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20130219 Firefox/58.0"
+func (ua UserAgent) firefox() string {
+	firefoxVer := fmt.Sprintf("%d.0", ua.intBetween(35, 129))
+	platformToken := randomElementFromSliceString([]string{
+		ua.linuxPlatformToken(),
+		ua.macPlatformToken("."),
+		ua.windowsPlatformToken(),
+	})
+	return fmt.Sprintf("Mozilla/5.0 (%s; rv:%s) Gecko/%s Firefox/%s",
+		platformToken, firefoxVer, ua.geckoVersion(), firefoxVer,
+	)
+}
+
+// internetExplorer generates a user agent string that resembles Internet Explorer
+// Example: "Mozilla/5.0 (compatible; MSIE 9.0; Windows 98; Win 9x 4.90; Trident/5.0)"
+func (ua UserAgent) internetExplorer() string {
+	return fmt.Sprintf("Mozilla/5.0 (compatible; MSIE %d.0; %s; Trident/%d.0)",
+		ua.intBetween(5, 11), ua.windowsPlatformToken(), ua.intBetween(3, 7),
+	)
+}
+
+// msEdge generates a user agent string that resembles MS Edge
+// Example: "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/533.0 (KHTML, like Gecko) Chrome/86.0.4685.32 Safari/533.0 Edg/86.0.4685.32"
+func (ua UserAgent) msEdge() string {
+	webKitVer := ua.webKitVersion(false)
+	chromiumVer := fmt.Sprintf("%d.0.%d.%d", ua.intBetween(79, 99), ua.intBetween(4000, 4844), ua.intBetween(10, 99))
+	platformToken := randomElementFromSliceString([]string{
+		ua.linuxPlatformToken(),
+		ua.windowsPlatformToken(),
+		ua.macPlatformToken("_"),
+	})
+	return fmt.Sprintf("Mozilla/5.0 (%s) AppleWebKit/%s (KHTML, like Gecko) Chrome/%s Safari/%s Edg/%s",
+		platformToken, webKitVer, chromiumVer, webKitVer, chromiumVer,
+	)
+}
+
+// opera generates a user agent string that resembles Opera.
+// Example: "Opera/8.40 (X11; Linux i686; zh-TW) Presto/2.12.181 Version/10.57"
+func (ua UserAgent) opera() string {
+	platformToken := randomElementFromSliceString([]string{
+		ua.linuxPlatformToken(),
+		ua.windowsPlatformToken(),
+	})
+	operaVer := fmt.Sprintf("%d.%d", ua.intBetween(8, 9), ua.intBetween(10, 99))
+	prestoVer := fmt.Sprintf("2.%d.%d", ua.intBetween(8, 12), ua.intBetween(160, 355))
+	ver := fmt.Sprintf("%d.%d", ua.intBetween(10, 12), ua.intBetween(0, 70))
+	return fmt.Sprintf("Opera/%s (%s; %s) Presto/%s Version/%s",
+		operaVer, platformToken, randomElementFromSliceString(langCodes), prestoVer, ver,
+	)
+}
+
+// safari generates a user agent string that resembles Safari.
+// Example: "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_7_3; bg-BG) AppleWebKit/548.43.16 (KHTML, like Gecko) Version/7.5 Safari/548.43.16"
+func (ua UserAgent) safari() string {
+	webKitVer := ua.webKitVersion(true)
+	safariVer := fmt.Sprintf("%d.%d", ua.intBetween(4, 17), ua.intBetween(0, 5))
+	if ua.intBetween(0, 100) < 50 {
+		safariVer = fmt.Sprintf("%s.%d", safariVer, ua.intBetween(1, 20))
+	}
+	platform := randomElementFromSliceString([]string{
+		fmt.Sprintf("Windows; U; %s; %s", ua.windowsPlatformToken(), randomElementFromSliceString(langCodes)),
+		fmt.Sprintf("%s; %s", ua.macPlatformToken("_"), randomElementFromSliceString(langCodes)),
+	})
+
+	return fmt.Sprintf("Mozilla/5.0 (%s) AppleWebKit/%s (KHTML, like Gecko) Version/%s Safari/%s",
+		platform, webKitVer, safariVer, webKitVer,
+	)
+}
+
+func (ua UserAgent) linuxPlatformToken() string {
+	return fmt.Sprintf("X11; Linux %s", randomElementFromSliceString(linuxProcessor))
+}
+
+func (ua UserAgent) macPlatformToken(sep string) string {
+	return fmt.Sprintf("Macintosh; %s Mac OS X %d%s%d%s%d",
+		randomElementFromSliceString(macProcessor), ua.intBetween(10, 17), sep, ua.intBetween(5, 8), sep, ua.intBetween(0, 9),
+	)
+}
+
+func (ua UserAgent) windowsPlatformToken() string {
+	return randomElementFromSliceString(windowsPlatformTokens)
+}
+
+// webKitVersion generates a random string that resembles an AppleWebKit version string.
+func (ua UserAgent) webKitVersion(withPatchVer bool) string {
+	majorVer := ua.intBetween(531, 618)
+	if withPatchVer {
+		return fmt.Sprintf("%d.%d.%d", majorVer, ua.intBetween(1, 50), ua.intBetween(1, 20))
+	}
+	return fmt.Sprintf("%d.%d", majorVer, ua.intBetween(0, 10))
+}
+
+// geckoVersion generates a random string that resembles a Gecko version string.
+func (ua UserAgent) geckoVersion() string {
+	const YYYYMMDD = "20060102"
+	minDate := time.Date(2010, 1, 1, 0, 0, 0, 0, time.UTC)
+	maxDate := time.Now()
+	randDuration := time.Duration(rand.Int63n(maxDate.Unix()-minDate.Unix())) * time.Second
+	return minDate.Add(randDuration).Format(YYYYMMDD)
+}
+
+// intBetween generates a random integer in the range [min, max].
+func (ua UserAgent) intBetween(min, max int) int {
+	boundary := interfaces.RandomIntegerBoundary{Start: min, End: max + 1}
+	return randomIntegerWithBoundary(boundary)
+}

user_agent_test.go

@@ -0,0 +1,31 @@
+package faker
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestUserAgent(t *testing.T) {
+	layoutEngines := []string{"Gecko", "KHTML", "Presto", "Trident"}
+	uaStringContains := func(elems []string, v string) bool {
+		for _, s := range elems {
+			if strings.Contains(v, s) {
+				return true
+			}
+		}
+		return false
+	}
+
+	ua, err := GetUserAgent().UserAgent(reflect.Value{})
+
+	if err != nil {
+		t.Error("Expected not error, got err", err)
+	}
+	if strings.Index(ua.(string), "Mozilla/5.0") != 0 {
+		t.Error("Expected User Agent string to begin with 'Mozilla/5.0'")
+	}
+	if !uaStringContains(layoutEngines, ua.(string)) {
+		t.Error("Expected User Agent string to contain a valid layout engine")
+	}
+}