From 2b5072f2b8ecbe59951d52d5e6c92162bf694fcb Mon Sep 17 00:00:00 2001
From: hohmannr <raphael.hohmann@tuta.io>
Date: Wed, 14 Jun 2023 21:19:01 +0200
Subject: [PATCH] feat: adds a changeable tag name (#27)

Signed-off-by: hohmannr <raphael.hohmann@tuta.io>
---
 example_with_custom_tags_test.go | 145 +++++++++++++++++++++++++++++++
 faker.go                         |   5 +-
 faker_test.go                    | 125 ++++++++++++++++----------
 pkg/errors/generic.go            |   1 +
 pkg/options/options.go           |  14 +++
 5 files changed, 242 insertions(+), 48 deletions(-)
 create mode 100644 example_with_custom_tags_test.go

diff --git a/example_with_custom_tags_test.go b/example_with_custom_tags_test.go
new file mode 100644
index 0000000..0ead2db
--- /dev/null
+++ b/example_with_custom_tags_test.go
@@ -0,0 +1,145 @@
+package faker_test
+
+import (
+	"fmt"
+
+	"github.com/go-faker/faker/v4"
+	"github.com/go-faker/faker/v4/pkg/options"
+)
+
+// SomeStructWithTags ...
+type SomeStructWithACustomTagName struct {
+	Latitude           float32           `custom:"lat"`
+	Longitude          float32           `custom:"long"`
+	RealAddress        faker.RealAddress `custom:"real_address"`
+	CreditCardNumber   string            `custom:"cc_number"`
+	CreditCardType     string            `custom:"cc_type"`
+	Email              string            `custom:"email"`
+	DomainName         string            `custom:"domain_name"`
+	IPV4               string            `custom:"ipv4"`
+	IPV6               string            `custom:"ipv6"`
+	Password           string            `custom:"password"`
+	Jwt                string            `custom:"jwt"`
+	PhoneNumber        string            `custom:"phone_number"`
+	MacAddress         string            `custom:"mac_address"`
+	URL                string            `custom:"url"`
+	UserName           string            `custom:"username"`
+	TollFreeNumber     string            `custom:"toll_free_number"`
+	E164PhoneNumber    string            `custom:"e_164_phone_number"`
+	TitleMale          string            `custom:"title_male"`
+	TitleFemale        string            `custom:"title_female"`
+	FirstName          string            `custom:"first_name"`
+	FirstNameMale      string            `custom:"first_name_male"`
+	FirstNameFemale    string            `custom:"first_name_female"`
+	LastName           string            `custom:"last_name"`
+	Name               string            `custom:"name"`
+	UnixTime           int64             `custom:"unix_time"`
+	Date               string            `custom:"date"`
+	Time               string            `custom:"time"`
+	MonthName          string            `custom:"month_name"`
+	Year               string            `custom:"year"`
+	DayOfWeek          string            `custom:"day_of_week"`
+	DayOfMonth         string            `custom:"day_of_month"`
+	Timestamp          string            `custom:"timestamp"`
+	Century            string            `custom:"century"`
+	TimeZone           string            `custom:"timezone"`
+	TimePeriod         string            `custom:"time_period"`
+	Word               string            `custom:"word"`
+	Sentence           string            `custom:"sentence"`
+	Paragraph          string            `custom:"paragraph"`
+	Currency           string            `custom:"currency"`
+	Amount             float64           `custom:"amount"`
+	AmountWithCurrency string            `custom:"amount_with_currency"`
+	UUIDHypenated      string            `custom:"uuid_hyphenated"`
+	UUID               string            `custom:"uuid_digit"`
+	Skip               string            `custom:"-"`
+	PaymentMethod      string            `custom:"oneof: cc, paypal, check, money order"` // oneof will randomly pick one of the comma-separated values supplied in the tag
+	AccountID          int               `custom:"oneof: 15, 27, 61"`                     // use commas to separate the values for now. Future support for other separator characters may be added
+	Price32            float32           `custom:"oneof: 4.95, 9.99, 31997.97"`
+	Price64            float64           `custom:"oneof: 47463.9463525, 993747.95662529, 11131997.978767990"`
+	NumS64             int64             `custom:"oneof: 1, 2"`
+	NumS32             int32             `custom:"oneof: -3, 4"`
+	NumS16             int16             `custom:"oneof: -5, 6"`
+	NumS8              int8              `custom:"oneof: 7, -8"`
+	NumU64             uint64            `custom:"oneof: 9, 10"`
+	NumU32             uint32            `custom:"oneof: 11, 12"`
+	NumU16             uint16            `custom:"oneof: 13, 14"`
+	NumU8              uint8             `custom:"oneof: 15, 16"`
+	NumU               uint              `custom:"oneof: 17, 18"`
+	PtrNumU            *uint             `custom:"oneof: 19, 20"`
+}
+
+func Example_withTagsAndCustomTagName() {
+
+	a := SomeStructWithTags{}
+	// just set the custom tag name option
+	err := faker.FakeData(&a, options.WithTagName("custom"))
+	if err != nil {
+		fmt.Println(err)
+	}
+	fmt.Printf("%+v", a)
+	/*
+		Result:
+		{
+			Latitude: 81.12195
+			Longitude: -84.38158
+			RealAddress: {Address:107 Guaymas Place City:Davis State:CA PostalCode:95616 Coordinates:{Latitude:38.567048 Longitude:-121.746046}}
+			CreditCardType: American Express
+			CreditCardNumber: 373641309057568
+			Email: mJBJtbv@OSAaT.ru
+			DomainName: FWZcaRE.ru,
+			IPV4: 99.23.42.63
+			IPV6: 975c:fb2c:2133:fbdd:beda:282e:1e0a:ec7d
+			Password: dfJdyHGuVkHBgnHLQQgpINApynzexnRpgIKBpiIjpTPOmNyMFb
+			Jwt: HDMNSOKhEIYkPIuHcVjfCtHlKkaqLGrUEqjKVkgR.HDMNSOKhEIYkPIuHcVjfCtHlKkaqLGrUEqjKVkgR.HDMNSOKhEIYkPIuHcVjfCtHlKkaqLGrUEqjKVkgR
+			PhoneNumber: 792-153-4861
+			MacAddress: cd:65:e1:d4:76:c6
+			URL: https://www.oEuqqAY.org/QgqfOhd
+			UserName: lVxELHS
+			TollFreeNumber: (777) 831-964572
+			E164PhoneNumber: +724891571063
+			TitleMale: Mr.
+			TitleFemale: Queen
+			FirstName: Whitney
+			FirstNameMale: Kenny
+			FirstNameFemale: Jana
+			LastName: Rohan
+			Name: Miss Casandra Kiehn
+			UnixTime: 1197930901
+			Date: 1982-02-27
+			Time: 03:10:25
+			MonthName: February
+			Year: 1996
+			DayOfWeek: Sunday
+			DayOfMonth: 20
+			Timestamp: 1973-06-21 14:50:46
+			Century: IV
+			TimeZone: Canada/Eastern
+			TimePeriod: AM
+			Word: nesciunt
+			Sentence: Consequatur perferendis aut sit voluptatem accusantium.
+			Paragraph: Aut consequatur sit perferendis accusantium voluptatem. Accusantium perferendis consequatur voluptatem sit aut. Aut sit accusantium consequatur voluptatem perferendis. Perferendis voluptatem aut accusantium consequatur sit.
+			Currency: IRR,
+			Amount: 88.990000,
+			AmountWithCurrency: XBB 49257.100000,
+			UUIDHypenated: 8f8e4463-9560-4a38-9b0c-ef24481e4e27,
+			UUID: 90ea6479fd0e4940af741f0a87596b73,
+			PaymentMethod: paypal,
+			AccountID: 61,
+			Price32: 4.95,
+			Price64: 993747.95662529
+			NumS64:	1
+			NumS32:	-3
+			NumS16:	5
+			NumS8:	-8
+			NumU64:	9
+			NumU32:	11
+			NumU16:	13
+			NumU8:	15
+			NumU:	17
+			PtrNumU: 19
+			Skip:
+		}
+	*/
+
+}
\ No newline at end of file
diff --git a/faker.go b/faker.go
index fc694d3..fe5c1d3 100644
--- a/faker.go
+++ b/faker.go
@@ -31,7 +31,6 @@ const (
 	letterIdxMask             = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
 	letterIdxMax              = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
 	maxRetry                  = 10000                // max number of retry for unique values
-	tagName                   = "faker"
 	keep                      = "keep"
 	unique                    = "unique"
 	ID                        = "uuid_digit"
@@ -443,7 +442,7 @@ func getFakedValue(a interface{}, opts *options.Options) (reflect.Value, error)
 					continue
 				}
 
-				tags := decodeTags(t, i)
+				tags := decodeTags(t, i, opts.TagName)
 				switch {
 				case tags.keepOriginal:
 					zero, err := isZero(reflect.ValueOf(a).Field(i))
@@ -606,7 +605,7 @@ func isZero(field reflect.Value) (bool, error) {
 	return reflect.Zero(field.Type()).Interface() == field.Interface(), nil
 }
 
-func decodeTags(typ reflect.Type, i int) structTag {
+func decodeTags(typ reflect.Type, i int, tagName string) structTag {
 	tagField := typ.Field(i).Tag.Get(tagName)
 	tags := strings.Split(tagField, ",")
 
diff --git a/faker_test.go b/faker_test.go
index 8069818..23d5474 100644
--- a/faker_test.go
+++ b/faker_test.go
@@ -251,51 +251,51 @@ type CStruct struct {
 }
 
 type TaggedStruct struct {
-	Latitude           float32 `faker:"lat"`
-	Longitude          float32 `faker:"long"`
-	CreditCardNumber   string  `faker:"cc_number"`
-	CreditCardType     string  `faker:"cc_type"`
-	Email              string  `faker:"email"`
-	DomainName         string  `faker:"domain_name"`
-	IPV4               string  `faker:"ipv4"`
-	IPV6               string  `faker:"ipv6"`
-	Password           string  `faker:"password"`
-	Jwt                string  `faker:"jwt"`
-	PhoneNumber        string  `faker:"phone_number"`
-	MacAddress         string  `faker:"mac_address"`
-	URL                string  `faker:"url"`
-	UserName           string  `faker:"username"`
-	TollFreeNumber     string  `faker:"toll_free_number"`
-	E164PhoneNumber    string  `faker:"e_164_phone_number"`
-	TitleMale          string  `faker:"title_male"`
-	TitleFemale        string  `faker:"title_female"`
-	FirstName          string  `faker:"first_name"`
-	FirstNameMale      string  `faker:"first_name_male"`
-	FirstNameFemale    string  `faker:"first_name_female"`
-	LastName           string  `faker:"last_name"`
-	Name               string  `faker:"name"`
-	ChineseFirstName   string  `faker:"chinese_first_name"`
-	ChineseLastName    string  `faker:"chinese_last_name"`
-	ChineseName        string  `faker:"chinese_name"`
-	UnixTime           int64   `faker:"unix_time"`
-	Date               string  `faker:"date"`
-	Time               string  `faker:"time"`
-	MonthName          string  `faker:"month_name"`
-	Year               string  `faker:"year"`
-	DayOfWeek          string  `faker:"day_of_week"`
-	DayOfMonth         string  `faker:"day_of_month"`
-	Timestamp          string  `faker:"timestamp"`
-	Century            string  `faker:"century"`
-	TimeZone           string  `faker:"timezone"`
-	TimePeriod         string  `faker:"time_period"`
-	Word               string  `faker:"word"`
-	Sentence           string  `faker:"sentence"`
-	Paragraph          string  `faker:"paragraph"`
-	Currency           string  `faker:"currency"`
-	Amount             float32 `faker:"amount"`
-	AmountWithCurrency string  `faker:"amount_with_currency"`
-	ID                 string  `faker:"uuid_digit"`
-	HyphenatedID       string  `faker:"uuid_hyphenated"`
+	Latitude           float32 `faker:"lat"                  custom_tag_name:"lat"                                 `
+	Longitude          float32 `faker:"long"                 custom_tag_name:"long"`
+	CreditCardNumber   string  `faker:"cc_number"            custom_tag_name:"cc_number"`
+	CreditCardType     string  `faker:"cc_type"              custom_tag_name:"cc_type"`
+	Email              string  `faker:"email"                custom_tag_name:"email"`
+	DomainName         string  `faker:"domain_name"          custom_tag_name:"domain_name"`
+	IPV4               string  `faker:"ipv4"                 custom_tag_name:"ipv4"`
+	IPV6               string  `faker:"ipv6"                 custom_tag_name:"ipv6"`
+	Password           string  `faker:"password"             custom_tag_name:"password"`
+	Jwt                string  `faker:"jwt"                  custom_tag_name:"jwt"`
+	PhoneNumber        string  `faker:"phone_number"         custom_tag_name:"phone_number"`
+	MacAddress         string  `faker:"mac_address"          custom_tag_name:"mac_address"`
+	URL                string  `faker:"url"                  custom_tag_name:"url"`
+	UserName           string  `faker:"username"             custom_tag_name:"username"`
+	TollFreeNumber     string  `faker:"toll_free_number"     custom_tag_name:"toll_free_number"`
+	E164PhoneNumber    string  `faker:"e_164_phone_number"   custom_tag_name:"e_164_phone_number"`
+	TitleMale          string  `faker:"title_male"           custom_tag_name:"title_male"`
+	TitleFemale        string  `faker:"title_female"         custom_tag_name:"title_female"`
+	FirstName          string  `faker:"first_name"           custom_tag_name:"first_name"`
+	FirstNameMale      string  `faker:"first_name_male"      custom_tag_name:"first_name_male"`
+	FirstNameFemale    string  `faker:"first_name_female"    custom_tag_name:"first_name_female"`
+	LastName           string  `faker:"last_name"            custom_tag_name:"last_name"`
+	Name               string  `faker:"name"                 custom_tag_name:"name"`
+	ChineseFirstName   string  `faker:"chinese_first_name"   custom_tag_name:"chinese_first_name"`
+	ChineseLastName    string  `faker:"chinese_last_name"    custom_tag_name:"chinese_last_name"`
+	ChineseName        string  `faker:"chinese_name"         custom_tag_name:"chinese_name"`
+	UnixTime           int64   `faker:"unix_time"            custom_tag_name:"unix_time"`
+	Date               string  `faker:"date"                 custom_tag_name:"date"`
+	Time               string  `faker:"time"                 custom_tag_name:"time"`
+	MonthName          string  `faker:"month_name"           custom_tag_name:"month_name"`
+	Year               string  `faker:"year"                 custom_tag_name:"year"`
+	DayOfWeek          string  `faker:"day_of_week"          custom_tag_name:"day_of_week"`
+	DayOfMonth         string  `faker:"day_of_month"         custom_tag_name:"day_of_month"`
+	Timestamp          string  `faker:"timestamp"            custom_tag_name:"timestamp"`
+	Century            string  `faker:"century"              custom_tag_name:"century"`
+	TimeZone           string  `faker:"timezone"             custom_tag_name:"timezone"`
+	TimePeriod         string  `faker:"time_period"          custom_tag_name:"time_period"`
+	Word               string  `faker:"word"                 custom_tag_name:"word"`
+	Sentence           string  `faker:"sentence"             custom_tag_name:"sentence"`
+	Paragraph          string  `faker:"paragraph"            custom_tag_name:"paragraph"`
+	Currency           string  `faker:"currency"             custom_tag_name:"currency"`
+	Amount             float32 `faker:"amount"               custom_tag_name:"amount"`
+	AmountWithCurrency string  `faker:"amount_with_currency" custom_tag_name:"amount_with_currency"`
+	ID                 string  `faker:"uuid_digit"           custom_tag_name:"uuid_digit"`
+	HyphenatedID       string  `faker:"uuid_hyphenated"      custom_tag_name:"uuid_hyphenated"`
 }
 
 func (t TaggedStruct) String() string {
@@ -2324,6 +2324,41 @@ func TestRandomMapSliceSize(t *testing.T) {
 	}
 }
 
+func TestWithTagName(t *testing.T) {
+	a := TaggedStruct{}
+	if err := FakeData(&a, options.WithTagName("custom_tag_name")); err != nil {
+		t.Error(err)
+	}
+
+	if err := assertAllStructFieldsNonZero(a); err != nil {
+		t.Error(err)
+	}
+}
+
+// assertAllStructFieldsNonZero asserts that the given struct s has all fields set to a non-zero value.
+// s must be a struct or a pointer to a struct, the function panics otherwise.
+func assertAllStructFieldsNonZero(s interface{}) error {
+	v := reflect.ValueOf(s)
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+
+	if v.Kind() != reflect.Struct {
+		panic("passed interface is not a struct or a pointer to a struct")
+	}
+
+	for i := 0; i < v.NumField(); i++ {
+		field := v.Field(i)
+		zero := reflect.Zero(field.Type())
+
+		if reflect.DeepEqual(field.Interface(), zero.Interface()) {
+			return fmt.Errorf("field '%s' has a zero value", v.Type().Field(i).Name)
+		}
+	}
+
+	return nil
+}
+
 func TestWithFieldsToIgnore(t *testing.T) {
 	a := AStruct{}
 	if err := FakeData(&a, options.WithFieldsToIgnore("Height", "Name")); err != nil {
diff --git a/pkg/errors/generic.go b/pkg/errors/generic.go
index bd38863..a0f7f05 100644
--- a/pkg/errors/generic.go
+++ b/pkg/errors/generic.go
@@ -16,6 +16,7 @@ var (
 	ErrTagNotSupported     = "Tag unsupported: %s"
 	ErrTagAlreadyExists    = "Tag exists"
 	ErrTagDoesNotExist     = "Tag does not exist"
+	ErrTagNameInvalid      = "Tag name is invalid"
 	ErrMoreArguments       = "Passed more arguments than is possible : (%d)"
 	ErrNotSupportedPointer = "Use sample:=new(%s)\n faker.FakeData(sample) instead"
 	ErrSmallerThanZero     = "Size:%d is smaller than zero."
diff --git a/pkg/options/options.go b/pkg/options/options.go
index d4d958b..b399fec 100644
--- a/pkg/options/options.go
+++ b/pkg/options/options.go
@@ -59,6 +59,8 @@ type Options struct {
 	RandomIntegerBoundary *interfaces.RandomIntegerBoundary
 	// RandomFloatBoundary sets the boundary for random float value generation. Boundaries should comply with float values constraints (IEEE 754)
 	RandomFloatBoundary *interfaces.RandomFloatBoundary
+	// SetTagName sets the tag name that should be used
+	TagName string
 }
 
 // MaxDepthOption used for configuring the max depth of nested struct for faker
@@ -106,6 +108,7 @@ func DefaultOption() *Options {
 	ops.MaxGenerateStringRetries = 1000000 //default
 	ops.RandomIntegerBoundary = (*interfaces.RandomIntegerBoundary)(atomic.LoadPointer(&iBoundary))
 	ops.RandomFloatBoundary = &interfaces.DefaultFloatBoundary
+	ops.TagName = "faker"
 	return ops
 }
 
@@ -236,6 +239,17 @@ func WithRandomFloatBoundaries(boundary interfaces.RandomFloatBoundary) OptionFu
 	}
 }
 
+// WithTagName sets the tag name to use. Default tag name is 'faker'.
+func WithTagName(tagName string) OptionFunc {
+	if tagName == "" {
+		err := errors.New(fakerErrors.ErrTagDoesNotExist)
+		panic(err)
+	}
+	return func(oo *Options) {
+		oo.TagName = tagName
+	}
+}
+
 // SetGenerateUniqueValues allows to set the single fake data generator functions to generate unique data.
 func SetGenerateUniqueValues(unique bool) {
 	generateUniqueValues.Store(unique)