+ IsValidEmail

validators.go

@@ -3,6 +3,7 @@ package utils
 import (
 	"net/url"
 	"os"
+	"regexp"
 
 	"github.com/google/uuid"
 )
@@ -58,6 +59,15 @@ func IsStringInSliceOfStrings(slice []string, target string) bool {
 	return false
 }
 
+// IsValidEmail returns true, if s is a email address.
+func IsValidEmail(s string) bool {
+	// Used Regex instead of mail.ParseAddress(), as the latter incorrectly recognizes samples such as “bad@domain” as a valid address
+	// Shoutout to emailregex.com for the almighty regular expression
+	return regexp.MustCompile(
+		`(?:[a-z0-9!#$%&'*+/=?^_{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])`,
+	).MatchString(s)
+}
+
 // IsValidURL returns true, if s is a valid URL
 func IsValidURL(s string) bool {
 	u, err := url.Parse(s)

validators_test.go

@@ -4,6 +4,42 @@ import (
 	"testing"
 )
 
+func TestDoesFileExist(t *testing.T) {
+	data := map[string]bool{
+		"/usr/bin/go":                   true,
+		"/etc/fstab":                    true,
+		"/etc/os-release":               true,
+		"/usr/bin":                      false,
+		"/home/derschmierigetypvomaldi": false,
+		"/tmp/plainTextPasswords.txt":   false,
+	}
+
+	for d, expectedResult := range data {
+		result := DoesFileExist(d)
+		if result != expectedResult {
+			t.Errorf("\ngot:    %t\nwanted: %t\nfor:    %q", result, expectedResult, d)
+		}
+	}
+}
+
+func TestDoesFolderExist(t *testing.T) {
+	data := map[string]bool{
+		"/home":                                true,
+		"/tmp":                                 true,
+		"/usr/bin":                             true,
+		"/home/derschmierigetypvomaldi":        false,
+		"/tmp/fdashfglkjdahjslkjfhjdsakljöhjf": false,
+		"/usr/bin/go":                          false,
+	}
+
+	for d, expectedResult := range data {
+		result := DoesFolderExist(d)
+		if result != expectedResult {
+			t.Errorf("\ngot:    %t\nwanted: %t\nfor:    %q", result, expectedResult, d)
+		}
+	}
+}
+
 func TestIsStringInSliceOfStrings(t *testing.T) {
 	slice1 := []string{"apple", "banana", "cherry", "date"}
 	target1 := "banana"
@@ -76,36 +112,23 @@ func TestIsValidUUID(t *testing.T) {
 	}
 }
 
-func TestDoesFileExist(t *testing.T) {
+func TestIsValidEmail(t *testing.T) {
 	data := map[string]bool{
-		"/usr/bin/go":                   true,
-		"/etc/fstab":                    true,
-		"/etc/os-release":               true,
-		"/usr/bin":                      false,
-		"/home/derschmierigetypvomaldi": false,
-		"/tmp/plainTextPasswords.txt":   false,
+		"test@example.com":          true,
+		"another.test@domain.co.uk": true,
+		"username@domain.c":         true,
+		"":                          false,
+		"invalid-email":             false,
+		"bad@domain":                false,
+		"@missingusername.com":      false,
+		"plainaddress":              false,
+		"@missingdomain":            false,
+		"missingatsign.com":         false,
+		"username@.com":             false,
 	}
 
 	for d, expectedResult := range data {
-		result := DoesFileExist(d)
-		if result != expectedResult {
-			t.Errorf("\ngot:    %t\nwanted: %t\nfor:    %q", result, expectedResult, d)
-		}
-	}
-}
-
-func TestDoesFolderExist(t *testing.T) {
-	data := map[string]bool{
-		"/home":                                true,
-		"/tmp":                                 true,
-		"/usr/bin":                             true,
-		"/home/derschmierigetypvomaldi":        false,
-		"/tmp/fdashfglkjdahjslkjfhjdsakljöhjf": false,
-		"/usr/bin/go":                          false,
-	}
-
-	for d, expectedResult := range data {
-		result := DoesFolderExist(d)
+		result := IsValidEmail(d)
 		if result != expectedResult {
 			t.Errorf("\ngot:    %t\nwanted: %t\nfor:    %q", result, expectedResult, d)
 		}