From 86faadca64d1e1306793b39e479c2e69c78419da Mon Sep 17 00:00:00 2001
From: "luke.rodham" <luke.rodham@sipsynergy.co.uk>
Date: Thu, 12 Jul 2018 09:49:26 +0100
Subject: [PATCH] master: added functionality to IsValid

---
 checker.go      | 10 ++++++++++
 checker_test.go | 27 +++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/checker.go b/checker.go
index 5735a60..04b4983 100644
--- a/checker.go
+++ b/checker.go
@@ -2,12 +2,22 @@ package checker
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 )
 
+var (
+	emailRegex = "^(?:(?:(?:(?:[a-zA-Z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])+(?:\\.([a-zA-Z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])+)*)|(?:(?:\\x22)(?:(?:(?:(?:\\x20|\\x09)*(?:\\x0d\\x0a))?(?:\\x20|\\x09)+)?(?:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f]|\\x21|[\\x23-\\x5b]|[\\x5d-\\x7e]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(?:\\(?:[\\x01-\\x09\\x0b\\x0c\\x0d-\\x7f]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}]))))*(?:(?:(?:\\x20|\\x09)*(?:\\x0d\\x0a))?(\\x20|\\x09)+)?(?:\\x22)))@(?:(?:(?:[a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(?:(?:[a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])(?:[a-zA-Z]|\\d|-|\\.|~|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*(?:[a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.)+(?:(?:[a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(?:(?:[a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])(?:[a-zA-Z]|\\d|-|\\.|~|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*(?:[a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.?$"
+)
+
 // IsValid preform a simple validation check to see if the email is correctly formatted.
 // An error is returned if not.
 func IsValid(email string) error {
+	emailRegex := regexp.MustCompile(emailRegex)
+	if !emailRegex.MatchString(email) {
+		return fmt.Errorf("invalid email")
+	}
+
 	return nil
 }
 
diff --git a/checker_test.go b/checker_test.go
index 2a28bfe..b78fa14 100644
--- a/checker_test.go
+++ b/checker_test.go
@@ -51,3 +51,30 @@ func TestIsGeneric(t *testing.T) {
 		}
 	}
 }
+
+func TestIsValid(t *testing.T) {
+	tests := []struct {
+		Email       string
+		ShouldError bool
+	}{
+		{
+			Email:       "example@asdas_-3-43222.com",
+			ShouldError: true,
+		},
+		{
+			Email:       "example--3-43222.com",
+			ShouldError: true,
+		},
+		{
+			Email:       "example@hotmail.com",
+			ShouldError: false,
+		},
+	}
+
+	for _, test := range tests {
+		err := checker.IsValid(test.Email)
+		if err != nil && test.ShouldError == false {
+			t.Error(err)
+		}
+	}
+}