WIP: Refactor to individual rules

src/Rules/DotsInUsername.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace ImLiam\UniqueGmailAddress\Rules;
+
+class DotsInUsername implements EmailRule
+{
+    public function normalize(string $email): string
+    {
+        [$username, $domain] = explode('@', $email, 2);
+        $username = str_replace('.', '', $username);
+
+        return $username . '@' . $domain;
+    }
+
+    public function regex(string $email): string
+    {
+        [$username, $domain] = explode('@', $email, 2);
+
+        $characters = array_map(function ($character) {
+            return preg_quote($character);
+        }, str_split($username));
+
+        // Each character in the username can have optional dots between them
+        return join('(\.?)+', $characters) . '@' . $domain;
+    }
+}

src/Rules/EmailRule.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace ImLiam\UniqueGmailAddress\Rules;
+
+interface EmailRule
+{
+    public function normalize(string $email): string;
+
+    public function regex(string $email): string;
+}

src/Rules/GmailDomain.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace ImLiam\UniqueGmailAddress\Rules;
+
+use ImLiam\UniqueGmailAddress\Util;
+
+class GmailDomain implements EmailRule
+{
+    public function normalize(string $email): string
+    {
+        if (! Util::isGmailAddress($email)) {
+            return $email;
+        }
+
+        [$username, $domain] = explode('@', $email, 2);
+
+        return $username . '@gmail.com';
+    }
+
+    public function regex(string $email): string
+    {
+        [$username, $domain] = explode('@', $email, 2);
+
+        return $username . '@(gmail|googlemail).com';
+    }
+}

src/Rules/MixedCase.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace ImLiam\UniqueGmailAddress\Rules;
+
+class MixedCase implements EmailRule
+{
+    public function normalize(string $email): string
+    {
+        return strtolower($email);
+    }
+
+    public function regex(string $email): string
+    {
+        [$username, $domain] = explode('@', $email, 2);
+
+        return '(?i)' . $username . '(?-i)' . '@' . $domain;
+    }
+}

src/Rules/TagInUsername.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace ImLiam\UniqueGmailAddress\Rules;
+
+class TagInUsername implements EmailRule
+{
+    protected string $separator;
+
+    public function __construct(string $separator = '+')
+    {
+        $this->separator = $separator;
+    }
+
+    public function normalize(string $email): string
+    {
+        [$username, $domain] = explode('@', $email, 2);
+        [$username, $tag] = explode($this->separator, $username, 2);
+
+        return $username . '@' . $domain;
+    }
+
+    public function regex(string $email): string
+    {
+        [$username, $domain] = explode('@', $email, 2);
+
+        return $username . '(' . preg_quote($this->separator) . '.*)?' . '@' . $domain;
+    }
+}

src/UniqueEmailAddress.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace ImLiam\UniqueGmailAddress;
+
+use ImLiam\UniqueGmailAddress\Rules\EmailRule;
+
+class UniqueEmailAddress
+{
+    protected string $email;
+
+    /** @var EmailRule[] */
+    protected array $rules = [];
+
+    public function __construct(string $email)
+    {
+        $this->email = $email;
+    }
+
+    public function normalize(): string
+    {
+        return array_reduce($this->rules, function (string $email, EmailRule $rule) {
+            return $rule->normalize($email);
+        }, $this->email);
+    }
+
+    public function getRegexWithDelimiters()
+    {
+        return '/' . $this->getRegex() . '/';
+    }
+
+    public function getRegex()
+    {
+        $email = str_replace('@', '\\@', $this->normalize());
+
+        return array_reduce($this->rules, function (string $email, EmailRule $rule) {
+            return $rule->regex($email);
+        }, $email);
+    }
+
+    public function matches($email)
+    {
+        /** @var array $matches */
+        preg_match($this->getRegexWithDelimiters(), $email, $matches);
+
+        return ! empty($matches);
+    }
+}

src/UniqueGmailAddress.php

@@ -2,79 +2,22 @@
 
 namespace ImLiam\UniqueGmailAddress;
 
-class UniqueGmailAddress
-{
-    protected string $originalEmail;
-    protected string $email;
+use ImLiam\UniqueGmailAddress\Rules\DotsInUsername;
+use ImLiam\UniqueGmailAddress\Rules\GmailDomain;
+use ImLiam\UniqueGmailAddress\Rules\MixedCase;
+use ImLiam\UniqueGmailAddress\Rules\TagInUsername;
 
+class UniqueGmailAddress extends UniqueEmailAddress
+{
     public function __construct(string $email)
     {
-        $this->originalEmail = $email;
-        $this->email = $this->normalizeAddress();
-    }
-
-    public function isGmailAddress()
-    {
-        return $this->stringEndsWith($this->originalEmail, '@googlemail.com')
-            || $this->stringEndsWith($this->originalEmail, '@gmail.com');
-    }
-
-    public function normalizeAddress()
-    {
-        if (! $this->isGmailAddress()) {
-            return $this->originalEmail;
-        }
-
-        $username = trim(strstr($this->originalEmail, '@', true));
-        $username = explode('+', $username)[0];
-        $username = str_replace('.', '', $username);
-
-        return "{$username}@gmail.com";
-    }
-
-    private function stringEndsWith(string $haystack, string $needle): bool
-    {
-        $length = strlen($needle);
-
-        if ($length === 0) {
-            return true;
-        }
-
-        return substr($haystack, -$length) === $needle;
-    }
-
-    private function getEscapedEmailUsername()
-    {
-        $emailUsername = strstr($this->email, '@', true);
-
-        $usernameCharacters = array_map(function ($character) {
-            return preg_quote($character);
-        }, str_split($emailUsername));
-
-        return join('(\.?)+', $usernameCharacters); // Each character in the username can have optional dots between them
-    }
-
-    public function getRegexWithDelimiters()
-    {
-        return '/' . $this->getRegex() . '/';
-    }
+        parent::__construct($email);
 
-    public function getRegex()
-    {
-        if (! $this->isGmailAddress()) {
-            return '^' . preg_quote($this->email) . '$'; // Must be an exact match
+        if (Util::isGmailAddress($this->email) || Util::isGsuiteAddress($this->email)) {
+            $this->rules[GmailDomain::class] = new GmailDomain();
+            // $this->rules[MixedCase::class] = new MixedCase();
+            $this->rules[DotsInUsername::class] = new DotsInUsername();
+            $this->rules[TagInUsername::class] = new TagInUsername('+');
         }
-
-        return '^' . $this->getEscapedEmailUsername() // Must start with the email username
-            . '(\+.*)?' // Can optionally include anything after a literal plus
-            . '\@(gmail|googlemail).com$'; // Must end with @gmail.com or @googlemail.com
-    }
-
-    public function matches($emailToCompare)
-    {
-        /** @var array $matches */
-        preg_match($this->getRegexWithDelimiters(), $emailToCompare, $matches);
-
-        return ! empty($matches);
     }
 }

src/UniqueGmailAddressRule.php

@@ -18,12 +18,12 @@ public function __construct($table = 'users', $column = 'email')
 
     public function passes($attribute, $value)
     {
-        $validator = new UniqueGmailAddress($value);
-
-        if (! $validator->isGmailAddress()) {
+        if (! Util::isGmailAddress($value) && ! Util::isGsuiteAddress($value)) {
             return true;
         }
 
+        $validator = new UniqueGmailAddress($value);
+
         return ! DB::table($this->table)->where($this->column, 'REGEXP', $validator->getRegexWithDelimiters())->exists();
     }
 

src/Util.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace ImLiam\UniqueGmailAddress;
+
+class Util
+{
+    public static function isGmailAddress(string $email): bool
+    {
+        [$username, $domain] = explode('@', $email, 2);
+
+        return in_array($domain, ['gmail.com', 'googlemail.com']);
+    }
+
+    public static function isGsuiteAddress(string $email): bool
+    {
+        if (static::isGmailAddress($email)) {
+            return false;
+        }
+
+        [$username, $domain] = explode('@', $email, 2);
+
+        /** @var string[] $mxRecords */
+        $successful = getmxrr($domain, $mxRecords);
+
+        if (! $successful) {
+            return false;
+        }
+
+        return in_array('aspmx.l.google.com', $mxRecords);
+    }
+}

tests/UniqueGmailAddressTest.php

@@ -29,6 +29,7 @@ public function a_denormalized_gmail_address_will_also_match()
     {
         $validator = new UniqueGmailAddress('[email protected]');
 
+        dd($validator->getRegex());
         $this->assertTrue($validator->matches('[email protected]'));
         $this->assertTrue($validator->matches('[email protected]'));
         $this->assertTrue($validator->matches('[email protected]'));
@@ -39,6 +40,6 @@ public function a_denormalized_gmail_address_can_be_normalized()
     {
         $validator = new UniqueGmailAddress('[email protected]');
 
-        $this->assertEquals('[email protected]', $validator->normalizeAddress());
+        $this->assertEquals('[email protected]', $validator->normalize());
     }
 }