diff --git a/go.mod b/go.mod
index 1b5cd11..4a51bc6 100644
--- a/go.mod
+++ b/go.mod
@@ -2,17 +2,21 @@ module verifycat
 
 go 1.22
 
-require github.com/gin-gonic/gin v1.9.1
+require (
+	github.com/gin-gonic/gin v1.9.1
+	github.com/stretchr/testify v1.8.4
+)
 
 require (
 	github.com/bytedance/sonic v1.10.2 // indirect
 	github.com/chenzhuoyu/base64x v0.0.0-20230717121745-296ad89f973d // indirect
 	github.com/chenzhuoyu/iasm v0.9.1 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.3 // indirect
 	github.com/gin-contrib/sse v0.1.0 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
-	github.com/go-playground/validator/v10 v10.17.0 // indirect
+	github.com/go-playground/validator/v10 v10.18.0 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.6 // indirect
@@ -21,6 +25,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.12 // indirect
 	golang.org/x/arch v0.7.0 // indirect
diff --git a/go.sum b/go.sum
index 8390f50..cb005b3 100644
--- a/go.sum
+++ b/go.sum
@@ -26,6 +26,8 @@ github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJn
 github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
 github.com/go-playground/validator/v10 v10.17.0 h1:SmVVlfAOtlZncTxRuinDPomC2DkXJ4E5T9gDA0AIH74=
 github.com/go-playground/validator/v10 v10.17.0/go.mod h1:9iXMNT7sEkjXb0I+enO7QXmzG6QCsPWY4zveKFVRSyU=
+github.com/go-playground/validator/v10 v10.18.0 h1:BvolUXjp4zuvkZ5YN5t7ebzbhlUtPsPm2S9NAZ5nl9U=
+github.com/go-playground/validator/v10 v10.18.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
 github.com/goccy/go-json v0.10.2 h1:CrxCmQqYDkv1z7lO7Wbh2HN93uovUHgrECaO5ZrCXAU=
 github.com/goccy/go-json v0.10.2/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
 github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
diff --git a/validate/api.go b/validate/api.go
index 971175d..2491a32 100644
--- a/validate/api.go
+++ b/validate/api.go
@@ -20,15 +20,6 @@ type CreditCardResult struct {
 	Brand string `json:"brand,omitempty"`
 }
 
-// Mapeamento de tipos para funções de validação
-var validationFuncMap = map[string]func(string) (bool, string){
-	"cpf":        func(value string) (bool, string) { return IsValidCPF(value), "" },
-	"cnpj":       func(value string) (bool, string) { return IsValidCNPJ(value), "" },
-	"url":        func(value string) (bool, string) { return IsValidURL(value), "" },
-	"creditcard": ValidateCreditCard,
-	"email":      func(value string) (bool, string) { return IsValidEmail(value), "" },
-}
-
 func ValidateHandler(c *gin.Context) {
 	var req ValidationRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
@@ -36,30 +27,40 @@ func ValidateHandler(c *gin.Context) {
 		return
 	}
 
-	validationFunc, exists := validationFuncMap[req.Type]
-	if !exists {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid validation type"})
-		return
-	}
-
 	var isValid bool
+	var message string
 	var brand string
 
-	if req.Type == "creditcard" {
-		isValid, brand = validationFunc(req.Value)
-	} else {
-		isValid, _ = validationFunc(req.Value)
+	switch req.Type {
+	case "cpf":
+		isValid = IsValidCPF(req.Value)
+		message = "CPF"
+	case "cnpj":
+		isValid = IsValidCNPJ(req.Value)
+		message = "CNPJ"
+	case "url":
+		isValid = IsValidURL(req.Value)
+		message = "URL"
+	case "creditcard":
+		isValid, brand = ValidateCreditCard(req.Value)
+		message = "Credit Card"
+	case "email":
+		isValid = IsValidEmail(req.Value)
+		message = "Email"
+	default:
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid validation type"})
+		return
 	}
 
 	var result interface{}
 	if req.Type == "creditcard" {
 		result = struct {
 			ValidationResult
-			CreditCard CreditCardResult `json:"creditcard,omitempty"`
+			CreditCard CreditCardResult `json:"creditCard,omitempty"`
 		}{
 			ValidationResult: ValidationResult{
 				IsValid: isValid,
-				Message: req.Type,
+				Message: message,
 			},
 			CreditCard: CreditCardResult{
 				Brand: brand,
@@ -68,7 +69,7 @@ func ValidateHandler(c *gin.Context) {
 	} else {
 		result = ValidationResult{
 			IsValid: isValid,
-			Message: req.Type,
+			Message: message,
 		}
 	}
 
diff --git a/validate/cnpj_test.go b/validate/cnpj_test.go
new file mode 100644
index 0000000..5fce56d
--- /dev/null
+++ b/validate/cnpj_test.go
@@ -0,0 +1,43 @@
+package validate
+
+import (
+	"testing"
+)
+
+func TestIsValidCNPJ(t *testing.T) {
+	// Caso de teste para CNPJ válido
+	validCNPJ := "11.222.333/0001-81"
+	if !IsValidCNPJ(validCNPJ) {
+		t.Errorf("Expected CNPJ %s to be valid, but got invalid", validCNPJ)
+	}
+
+	// Caso de teste para CNPJ inválido
+	invalidCNPJ := "11.222.333/0001-82"
+	if IsValidCNPJ(invalidCNPJ) {
+		t.Errorf("Expected CNPJ %s to be invalid, but got valid", invalidCNPJ)
+	}
+
+	// Caso de teste para CNPJ vazio
+	emptyCNPJ := ""
+	if IsValidCNPJ(emptyCNPJ) {
+		t.Errorf("Expected empty CNPJ to be invalid, but got valid")
+	}
+
+	// Caso de teste para CNPJ com tamanho incorreto
+	invalidSizeCNPJ := "11.222.333"
+	if IsValidCNPJ(invalidSizeCNPJ) {
+		t.Errorf("Expected CNPJ %s with incorrect size to be invalid, but got valid", invalidSizeCNPJ)
+	}
+
+	// Caso de teste para CNPJ com dígitos repetidos
+	repeatedDigitsCNPJ := "11.111.111/1111-11"
+	if IsValidCNPJ(repeatedDigitsCNPJ) {
+		t.Errorf("Expected CNPJ %s with repeated digits to be invalid, but got valid", repeatedDigitsCNPJ)
+	}
+
+	// Caso de teste para CNPJ sem caracteres especiais
+	withoutSpecialCharsCNPJ := "11222333000181"
+	if !IsValidCNPJ(withoutSpecialCharsCNPJ) {
+		t.Errorf("Expected CNPJ %s without special characters to be valid, but got invalid", withoutSpecialCharsCNPJ)
+	}
+}
diff --git a/validate/cpf.go b/validate/cpf.go
index 42d1ac7..638f492 100644
--- a/validate/cpf.go
+++ b/validate/cpf.go
@@ -33,6 +33,11 @@ func IsValidCPF(cpf string) bool {
 	cpf = strings.ReplaceAll(cpf, ".", "")
 	cpf = strings.ReplaceAll(cpf, "-", "")
 
+	// Check if the CPF contains only numeric digits
+	if _, err := strconv.Atoi(cpf); err != nil {
+		return false
+	}
+
 	// Check for known invalid CPFs
 	if strings.Count(cpf, string(cpf[0])) == 11 {
 		return false
@@ -41,11 +46,16 @@ func IsValidCPF(cpf string) bool {
 	// Extract digits from CPF
 	digits := make([]int, 11)
 	for i := 0; i < 11; i++ {
-		digit, err := strconv.Atoi(string(cpf[i]))
-		if err != nil {
-			// Handle error as needed
+		if i < len(cpf) {
+			digit, err := strconv.Atoi(string(cpf[i]))
+			if err != nil {
+				// Handle error as needed
+			}
+			digits[i] = digit
+		} else {
+			// Handle the case where the string is too short
+			return false
 		}
-		digits[i] = digit
 	}
 
 	// Calculate the first verification digit
diff --git a/validate/cpf_test.go b/validate/cpf_test.go
new file mode 100644
index 0000000..b8906cb
--- /dev/null
+++ b/validate/cpf_test.go
@@ -0,0 +1,58 @@
+package validate
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestIsValidCPFAllSameNumbers(t *testing.T) {
+	// Test with CPFs where all numbers are the same (0 to 9)
+	for digit := 0; digit <= 9; digit++ {
+		allSameCPF := fmt.Sprintf("%d%d%d.%d%d%d.%d%d%d-%d%d", digit, digit, digit, digit, digit, digit, digit, digit, digit, digit, digit)
+		result := IsValidCPF(allSameCPF)
+
+		if result {
+			t.Errorf("Expected CPF %s to be invalid, but got valid", allSameCPF)
+		}
+	}
+}
+
+func TestIsValidCPFValid(t *testing.T) {
+	// Test a valid CPF
+	validCPF := "123.456.789-09"
+	result := IsValidCPF(validCPF)
+
+	if !result {
+		t.Errorf("Expected CPF %s to be valid, but got invalid", validCPF)
+	}
+}
+
+func TestIsValidCPFInvalid(t *testing.T) {
+	// Test an invalid CPF
+	invalidCPF := "111.222.333-44"
+	result := IsValidCPF(invalidCPF)
+
+	if result {
+		t.Errorf("Expected CPF %s to be invalid, but got valid", invalidCPF)
+	}
+}
+
+func TestIsValidCPFShortInput(t *testing.T) {
+	// Test with a short input string
+	shortCPF := "123.456"
+	result := IsValidCPF(shortCPF)
+
+	if result {
+		t.Errorf("Expected CPF %s to be invalid due to short input, but got valid", shortCPF)
+	}
+}
+
+func TestIsValidCPFNonNumericInput(t *testing.T) {
+	// Test with non-numeric input
+	nonNumericCPF := "ABC.DEF.GHI-JK"
+	result := IsValidCPF(nonNumericCPF)
+
+	if result {
+		t.Errorf("Expected CPF %s to be invalid due to non-numeric characters, but got valid", nonNumericCPF)
+	}
+}
diff --git a/validate/creditcard_test.go b/validate/creditcard_test.go
new file mode 100644
index 0000000..fecae3f
--- /dev/null
+++ b/validate/creditcard_test.go
@@ -0,0 +1,57 @@
+package validate
+
+import (
+	"testing"
+)
+
+// TestIsValidCreditCard verifica se a função IsValidCreditCard funciona corretamente.
+func TestIsValidCreditCard(t *testing.T) {
+	// Teste para um número de cartão válido
+	validCard := "1234567812345670"
+	if !IsValidCreditCard(validCard) {
+		t.Errorf("Erro para cartão válido. Esperado true, obteve false.")
+	}
+
+	// Teste para um número de cartão inválido
+	invalidCard := "1234-5678-1234-5678"
+	if IsValidCreditCard(invalidCard) {
+		t.Errorf("Erro para cartão inválido. Esperado false, obteve true.")
+	}
+}
+
+// TestValidateCreditCard verifica se a função ValidateCreditCard funciona corretamente.
+func TestValidateCreditCard(t *testing.T) {
+	// Teste para um número de cartão válido
+	validCard := "4539445433274775"
+	isValid, brand := ValidateCreditCard(validCard)
+	if !isValid || brand != "Visa" {
+		t.Errorf("Erro para cartão válido. Esperado (true, 'Visa'), obteve (%t, '%s').", isValid, brand)
+	}
+
+	// Teste para um número de cartão inválido
+	invalidCard := "1234-5678-1234-5678"
+	isValid, brand = ValidateCreditCard(invalidCard)
+	if isValid || brand != "" {
+		t.Errorf("Erro para cartão inválido. Esperado (false, ''), obteve (%t, '%s').", isValid, brand)
+	}
+}
+
+// TestIdentifyCardBrand verifica se a função IdentifyCardBrand funciona corretamente.
+func TestIdentifyCardBrand(t *testing.T) {
+	// Teste para diferentes marcas de cartão
+	visaCard := "4123456781234567"
+	if brand := IdentifyCardBrand(visaCard); brand != "Visa" {
+		t.Errorf("Erro para cartão Visa. Esperado 'Visa', obteve '%s'.", brand)
+	}
+
+	masterCard := "5212345678901234"
+	if brand := IdentifyCardBrand(masterCard); brand != "MasterCard" {
+		t.Errorf("Erro para cartão MasterCard. Esperado 'MasterCard', obteve '%s'.", brand)
+	}
+
+	amexCard := "371234567890123"
+	if brand := IdentifyCardBrand(amexCard); brand != "American Express" {
+		t.Errorf("Erro para cartão American Express. Esperado 'American Express', obteve '%s'.", brand)
+	}
+
+}
diff --git a/validate/email_test.go b/validate/email_test.go
new file mode 100644
index 0000000..452a236
--- /dev/null
+++ b/validate/email_test.go
@@ -0,0 +1,59 @@
+package validate
+
+import (
+	"testing"
+)
+
+func TestIsValidEmail_ValidEmail(t *testing.T) {
+	email := "test@example.com"
+	result := IsValidEmail(email)
+
+	if !result {
+		t.Errorf("Expected email '%s' to be valid, but it was invalid", email)
+	}
+}
+
+func TestIsValidEmail_InvalidEmail(t *testing.T) {
+	email := "invalid-email"
+	result := IsValidEmail(email)
+
+	if result {
+		t.Errorf("Expected email '%s' to be invalid, but it was valid", email)
+	}
+}
+
+func TestIsValidEmail_EmptyEmail(t *testing.T) {
+	email := ""
+	result := IsValidEmail(email)
+
+	if result {
+		t.Errorf("Expected empty email to be invalid, but it was valid")
+	}
+}
+
+func TestIsValidEmail_InvalidCharacters(t *testing.T) {
+	email := "test!@example.com"
+	result := IsValidEmail(email)
+
+	if result {
+		t.Errorf("Expected email '%s' with invalid characters to be invalid, but it was valid", email)
+	}
+}
+
+func TestIsValidEmail_InvalidDomain(t *testing.T) {
+	email := "test@example"
+	result := IsValidEmail(email)
+
+	if result {
+		t.Errorf("Expected email '%s' with invalid domain to be invalid, but it was valid", email)
+	}
+}
+
+func TestIsValidEmail_InvalidTLD(t *testing.T) {
+	email := "test@example.c"
+	result := IsValidEmail(email)
+
+	if result {
+		t.Errorf("Expected email '%s' with invalid top-level domain to be invalid, but it was valid", email)
+	}
+}
diff --git a/validate/url_test.go b/validate/url_test.go
new file mode 100644
index 0000000..5ae81bb
--- /dev/null
+++ b/validate/url_test.go
@@ -0,0 +1,50 @@
+package validate
+
+import (
+	"testing"
+)
+
+func TestIsValidURL_ValidURL_HTTP(t *testing.T) {
+	urlStr := "http://www.example.com"
+	result := IsValidURL(urlStr)
+
+	if !result {
+		t.Errorf("Expected URL '%s' to be valid, but it was invalid", urlStr)
+	}
+}
+
+func TestIsValidURL_ValidURL_HTTPS(t *testing.T) {
+	urlStr := "https://www.example.com"
+	result := IsValidURL(urlStr)
+
+	if !result {
+		t.Errorf("Expected URL '%s' to be valid, but it was invalid", urlStr)
+	}
+}
+
+func TestIsValidURL_InvalidScheme(t *testing.T) {
+	urlStr := "ftp://www.example.com"
+	result := IsValidURL(urlStr)
+
+	if result {
+		t.Errorf("Expected URL '%s' with invalid scheme to be invalid, but it was valid", urlStr)
+	}
+}
+
+func TestIsValidURL_InvalidHost(t *testing.T) {
+	urlStr := "http://invalid-host"
+	result := IsValidURL(urlStr)
+
+	if result {
+		t.Errorf("Expected URL '%s' with invalid host to be invalid, but it was valid", urlStr)
+	}
+}
+
+func TestIsValidURL_EmptyURL(t *testing.T) {
+	urlStr := ""
+	result := IsValidURL(urlStr)
+
+	if result {
+		t.Errorf("Expected empty URL to be invalid, but it was valid")
+	}
+}