Email addresses with single quote should not be valid (#268)

* Fixes issue for email addresses with single quote in domain part
* specify version in cli for older php versions

Co-authored-by: Eduardo Gulias Davis <eduardomgulias@gmail.com>

.gitattributes

@@ -1,4 +1,7 @@
-/Tests export-ignore
 /documentation export-ignore
+/tests export-ignore
 /.* export-ignore
-/phpunit.xml.dist
+/phpunit.xml.dist export-ignore
+/psalm.xml export-ignore
+/psalm.baseline.xml export-ignore
+/README.md export-ignore

.travis.yml

@@ -8,26 +8,38 @@ matrix:
     - php: 5.5
       dist: trusty
     - php: 5.6
+      env:
       dist: xenial
     - php: 7.0
       dist: xenial
     - php: 7.1
+      env:
+        - psalm=yes
       dist: bionic
     - php: 7.2
+      env:
+        - psalm=yes
       dist: bionic
     - php: 7.3
       dist: bionic
+      env:
+        - psalm=yes
     - php: 7.4
+      env:
+        - psalm=yes
       dist: bionic
 
 install:
   - if [ "$deps" = "low" ]; then composer update --prefer-lowest; else composer install; fi
+  - if [ "$psalm" = "yes" ]; then composer require --dev vimeo/psalm:3.18.2; fi
 
 before_script:
   - mkdir -p build/logs
 
 script:
   - vendor/bin/phpunit --coverage-clover build/logs/clover.xml
+  - if [ "$psalm" = "yes" ]; then vendor/bin/psalm; fi
 
 after_script:
   - php vendor/bin/coveralls
+  

EmailValidator/Validation/DNSCheckValidation.php

@@ -1,72 +0,0 @@
-<?php
-
-namespace Egulias\EmailValidator\Validation;
-
-use Egulias\EmailValidator\EmailLexer;
-use Egulias\EmailValidator\Exception\InvalidEmail;
-use Egulias\EmailValidator\Warning\NoDNSMXRecord;
-use Egulias\EmailValidator\Exception\NoDNSRecord;
-
-class DNSCheckValidation implements EmailValidation
-{
-    /**
-     * @var array
-     */
-    private $warnings = [];
-
-    /**
-     * @var InvalidEmail
-     */
-    private $error;
-    
-    public function __construct()
-    {
-        if (!extension_loaded('intl')) {
-            throw new \LogicException(sprintf('The %s class requires the Intl extension.', __CLASS__));
-        }
-    }
-
-    public function isValid($email, EmailLexer $emailLexer)
-    {
-        // use the input to check DNS if we cannot extract something similar to a domain
-        $host = $email;
-
-        // Arguable pattern to extract the domain. Not aiming to validate the domain nor the email
-        if (false !== $lastAtPos = strrpos($email, '@')) {
-            $host = substr($email, $lastAtPos + 1);
-        }
-
-        return $this->checkDNS($host);
-    }
-
-    public function getError()
-    {
-        return $this->error;
-    }
-
-    public function getWarnings()
-    {
-        return $this->warnings;
-    }
-
-    protected function checkDNS($host)
-    {
-        $variant = INTL_IDNA_VARIANT_2003;
-        if ( defined('INTL_IDNA_VARIANT_UTS46') ) {
-            $variant = INTL_IDNA_VARIANT_UTS46;
-        }
-        $host = rtrim(idn_to_ascii($host, IDNA_DEFAULT, $variant), '.') . '.';
-
-        $Aresult = true;
-        $MXresult = checkdnsrr($host, 'MX');
-
-        if (!$MXresult) {
-            $this->warnings[NoDNSMXRecord::CODE] = new NoDNSMXRecord();
-            $Aresult = checkdnsrr($host, 'A') || checkdnsrr($host, 'AAAA');
-            if (!$Aresult) {
-                $this->error = new NoDNSRecord();
-            }
-        }
-        return $MXresult || $Aresult;
-    }
-}

README.md

@@ -1,7 +1,12 @@
 # EmailValidator
-[![Build Status](https://travis-ci.org/egulias/EmailValidator.svg?branch=master)](https://travis-ci.org/egulias/EmailValidator) [![Coverage Status](https://coveralls.io/repos/egulias/EmailValidator/badge.svg?branch=master)](https://coveralls.io/r/egulias/EmailValidator?branch=master) [![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/egulias/EmailValidator/badges/quality-score.png?b=master)](https://scrutinizer-ci.com/g/egulias/EmailValidator/?branch=master) [![SensioLabsInsight](https://insight.sensiolabs.com/projects/22ba6692-9c02-42e5-a65d-1c5696bfffc6/small.png)](https://insight.sensiolabs.com/projects/22ba6692-9c02-42e5-a65d-1c5696bfffc6)
-=============================
-## Suported RFCs ##
+
+[![Build Status](https://travis-ci.org/egulias/EmailValidator.svg?branch=master)](https://travis-ci.org/egulias/EmailValidator)
+[![Coverage Status](https://coveralls.io/repos/egulias/EmailValidator/badge.svg?branch=master)](https://coveralls.io/r/egulias/EmailValidator?branch=master)
+[![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/egulias/EmailValidator/badges/quality-score.png?b=master)](https://scrutinizer-ci.com/g/egulias/EmailValidator/?branch=master)
+[![SensioLabsInsight](https://insight.sensiolabs.com/projects/22ba6692-9c02-42e5-a65d-1c5696bfffc6/small.png)](https://insight.sensiolabs.com/projects/22ba6692-9c02-42e5-a65d-1c5696bfffc6)
+
+## Supported RFCs ##
+
 This library aims to support:
 
 RFC 5321, 5322, 6530, 6531, 6532.
@@ -9,7 +14,7 @@ RFC 5321, 5322, 6530, 6531, 6532.
 ## Requirements ##
 
  * [Composer](https://getcomposer.org) is required for installation
- * [Spoofchecking](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/SpoofCheckValidation.php) and [DNSCheckValidation](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/DNSCheckValidation.php) validation requires that your PHP system has the [PHP Internationalization Libraries](https://php.net/manual/en/book.intl.php) (also known as PHP Intl)
+ * [Spoofchecking](/src/Validation/SpoofCheckValidation.php) and [DNSCheckValidation](/src/Validation/DNSCheckValidation.php) validation requires that your PHP system has the [PHP Internationalization Libraries](https://php.net/manual/en/book.intl.php) (also known as PHP Intl)
 
 ## Installation ##
 
@@ -20,6 +25,7 @@ composer require egulias/email-validator
 ```
 
 ## Getting Started ##
+
 `EmailValidator`requires you to decide which (or combination of them) validation/s strategy/ies you'd like to follow for each [validation](#available-validations).
 
 A basic example with the RFC validation
@@ -36,11 +42,11 @@ $validator->isValid("example@example.com", new RFCValidation()); //true
 
 ### Available validations ###
 
-1. [RFCValidation](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/RFCValidation.php)
-2. [NoRFCWarningsValidation](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/NoRFCWarningsValidation.php)
-3. [DNSCheckValidation](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/DNSCheckValidation.php)
-4. [SpoofCheckValidation](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/SpoofCheckValidation.php)
-5. [MultipleValidationWithAnd](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/MultipleValidationWithAnd.php)
+1. [RFCValidation](/src/Validation/RFCValidation.php)
+2. [NoRFCWarningsValidation](/src/Validation/NoRFCWarningsValidation.php)
+3. [DNSCheckValidation](/src/Validation/DNSCheckValidation.php)
+4. [SpoofCheckValidation](/src/Validation/SpoofCheckValidation.php)
+5. [MultipleValidationWithAnd](/src/Validation/MultipleValidationWithAnd.php)
 6. [Your own validation](#how-to-extend)
 
 `MultipleValidationWithAnd`
@@ -65,10 +71,11 @@ $validator->isValid("example@example.com", $multipleValidations); //true
 
 ### How to extend ###
 
-It's easy! You just need to implement [EmailValidation](https://github.com/egulias/EmailValidator/blob/master/EmailValidator/Validation/EmailValidation.php) and you can use your own validation.
+It's easy! You just need to implement [EmailValidation](/src/Validation/EmailValidation.php) and you can use your own validation.
 
 
 ## Other Contributors ##
+
 (You can find current contributors [here](https://github.com/egulias/EmailValidator/graphs/contributors))
 
 As this is a port from another library and work, here are other people related to the previous one:
@@ -78,5 +85,5 @@ As this is a port from another library and work, here are other people related t
 * Dominic Sayers [@dominicsayers](https://github.com/dominicsayers):  	The original isemail function
 
 ## License ##
-Released under the MIT License attached with this code.
 
+Released under the MIT License attached with this code.

Tests/EmailValidator/Validation/DNSCheckValidationTest.php

@@ -1,63 +0,0 @@
-<?php
-
-namespace Egulias\Tests\EmailValidator\Validation;
-
-use Egulias\EmailValidator\EmailLexer;
-use Egulias\EmailValidator\Exception\NoDNSRecord;
-use Egulias\EmailValidator\Validation\DNSCheckValidation;
-use Egulias\EmailValidator\Warning\NoDNSMXRecord;
-use PHPUnit\Framework\TestCase;
-
-class DNSCheckValidationTest extends TestCase
-{
-    public function validEmailsProvider()
-    {
-        return [
-            // dot-atom
-            ['Abc@example.com'],
-            ['ABC@EXAMPLE.COM'],
-            ['Abc.123@example.com'],
-            ['user+mailbox/department=shipping@example.com'],
-            ['!#$%&\'*+-/=?^_`.{|}~@example.com'],
-
-            // quoted string
-            ['"Abc@def"@example.com'],
-            ['"Fred\ Bloggs"@example.com'],
-            ['"Joe.\\Blow"@example.com'],
-            
-            // unicide
-            ['ñandu.cl'],
-        ];
-    }
-
-    /**
-     * @dataProvider validEmailsProvider
-     */
-    public function testValidDNS($validEmail)
-    {
-        $validation = new DNSCheckValidation();
-        $this->assertTrue($validation->isValid($validEmail, new EmailLexer()));
-    }
-
-    public function testInvalidDNS()
-    {
-        $validation = new DNSCheckValidation();
-        $this->assertFalse($validation->isValid("example@invalid.example.com", new EmailLexer()));
-    }
-
-    public function testDNSWarnings()
-    {
-        $validation = new DNSCheckValidation();
-        $expectedWarnings = [NoDNSMXRecord::CODE => new NoDNSMXRecord()];
-        $validation->isValid("example@invalid.example.com", new EmailLexer());
-        $this->assertEquals($expectedWarnings, $validation->getWarnings());
-    }
-
-    public function testNoDNSError()
-    {
-        $validation = new DNSCheckValidation();
-        $expectedError = new NoDNSRecord();
-        $validation->isValid("example@invalid.example.com", new EmailLexer());
-        $this->assertEquals($expectedError, $validation->getError());
-    }
-}

composer.json

@@ -14,24 +14,25 @@
   },
   "require": {
     "php": ">=5.5",
-    "doctrine/lexer": "^1.0.1"
+    "doctrine/lexer": "^1.0.1",
+    "symfony/polyfill-intl-idn": "^1.10"
   },
   "require-dev": {
-    "satooshi/php-coveralls": "^1.0.1",
+    "dominicsayers/isemail": "^3.0.7",
     "phpunit/phpunit": "^4.8.36|^7.5.15",
-    "dominicsayers/isemail": "^3.0.7"
+    "satooshi/php-coveralls": "^1.0.1"
   },
   "suggest": {
     "ext-intl": "PHP Internationalization Libraries are required to use the SpoofChecking validation"
   },
   "autoload": {
     "psr-4": {
-      "Egulias\\EmailValidator\\": "EmailValidator"
+      "Egulias\\EmailValidator\\": "src"
     }
   },
   "autoload-dev": {
     "psr-4": {
-      "Egulias\\Tests\\": "Tests"
+      "Egulias\\EmailValidator\\Tests\\": "tests"
     }
   }
 }

phpunit.xml.dist

@@ -12,14 +12,14 @@
 >
 <testsuites>
   <testsuite name="EmailValidator Test Suite">
-    <directory>./Tests/EmailValidator</directory>
+    <directory>./tests/EmailValidator</directory>
     <exclude>./vendor/</exclude>
   </testsuite>
 </testsuites>
 
 <filter>
   <whitelist>
-    <directory>./EmailValidator/</directory>
+    <directory>./src/</directory>
   </whitelist>
 </filter>
 </phpunit>

psalm.baseline.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<files psalm-version="3.8.3@389af1bfc739bfdff3f9e3dc7bd6499aee51a831">
+  <file src="src/EmailLexer.php">
+    <DocblockTypeContradiction occurrences="1">
+      <code>self::$nullToken</code>
+    </DocblockTypeContradiction>
+  </file>
+  <file src="src/Parser/Parser.php">
+    <MissingReturnType occurrences="1">
+      <code>parse</code>
+    </MissingReturnType>
+  </file>
+  <file src="src/Validation/SpoofCheckValidation.php">
+    <UndefinedClass occurrences="2">
+      <code>Spoofchecker</code>
+      <code>Spoofchecker</code>
+    </UndefinedClass>
+  </file>
+</files>

psalm.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<psalm
+    requireVoidReturnType="false"
+    totallyTyped="false"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config ./vendor/vimeo/psalm/config.xsd"
+    errorBaseline="./psalm.baseline.xml"
+>
+    <projectFiles>
+        <directory name="src" />
+        <ignoreFiles>
+            <directory name="vendor" />
+        </ignoreFiles>
+    </projectFiles>
+
+    <issueHandlers>
+    </issueHandlers>
+</psalm>

src/EmailLexer.php

@@ -13,6 +13,7 @@ class EmailLexer extends AbstractLexer
     const S_BACKSLASH        = 92;
     const S_DOT              = 46;
     const S_DQUOTE           = 34;
+    const S_SQUOTE           = 39;
     const S_OPENPARENTHESIS  = 49;
     const S_CLOSEPARENTHESIS = 261;
     const S_OPENBRACKET      = 262;
@@ -58,6 +59,7 @@ class EmailLexer extends AbstractLexer
         '/'    => self::S_SLASH,
         ','    => self::S_COMMA,
         '.'    => self::S_DOT,
+        "'"    => self::S_SQUOTE,
         '"'    => self::S_DQUOTE,
         '-'    => self::S_HYPHEN,
         '::'   => self::S_DOUBLECOLON,
@@ -73,10 +75,37 @@ class EmailLexer extends AbstractLexer
         '\0'   => self::C_NUL,
     );
 
+    /**
+     * @var bool
+     */
     protected $hasInvalidTokens = false;
 
-    protected $previous;
+    /**
+     * @var array
+     *
+     * @psalm-var array{value:string, type:null|int, position:int}|array<empty, empty>
+     */
+    protected $previous = [];
 
+    /**
+     * The last matched/seen token.
+     *
+     * @var array
+     *
+     * @psalm-var array{value:string, type:null|int, position:int}
+     */
+    public $token;
+
+    /**
+     * The next token in the input.
+     *
+     * @var array|null
+     */
+    public $lookahead;
+
+    /**
+     * @psalm-var array{value:'', type:null, position:0}
+     */
     private static $nullToken = [
         'value' => '',
         'type' => null,
@@ -86,6 +115,7 @@ class EmailLexer extends AbstractLexer
     public function __construct()
     {
         $this->previous = $this->token = self::$nullToken;
+        $this->lookahead = null;
     }
 
     /**
@@ -98,15 +128,20 @@ class EmailLexer extends AbstractLexer
         $this->previous = $this->token = self::$nullToken;
     }
 
+    /**
+     * @return bool
+     */
     public function hasInvalidTokens()
     {
         return $this->hasInvalidTokens;
     }
 
     /**
-     * @param string $type
+     * @param int $type
      * @throws \UnexpectedValueException
      * @return boolean
+     *
+     * @psalm-suppress InvalidScalarArgument
      */
     public function find($type)
     {
@@ -122,7 +157,7 @@ class EmailLexer extends AbstractLexer
     /**
      * getPrevious
      *
-     * @return array token
+     * @return array
      */
     public function getPrevious()
     {
@@ -196,6 +231,11 @@ class EmailLexer extends AbstractLexer
         return  self::GENERIC;
     }
 
+    /**
+     * @param string $value
+     *
+     * @return bool
+     */
     protected function isValid($value)
     {
         if (isset($this->charValue[$value])) {

src/EmailParser.php

@@ -17,11 +17,33 @@ class EmailParser
 {
     const EMAIL_MAX_LENGTH = 254;
 
-    protected $warnings;
+    /**
+     * @var array
+     */
+    protected $warnings = [];
+
+    /**
+     * @var string
+     */
     protected $domainPart = '';
+
+    /**
+     * @var string
+     */
     protected $localPart = '';
+    /**
+     * @var EmailLexer
+     */
     protected $lexer;
+
+    /**
+     * @var LocalPart
+     */
     protected $localPartParser;
+
+    /**
+     * @var DomainPart
+     */
     protected $domainPartParser;
 
     public function __construct(EmailLexer $lexer)
@@ -29,7 +51,6 @@ class EmailParser
         $this->lexer = $lexer;
         $this->localPartParser = new LocalPart($this->lexer);
         $this->domainPartParser = new DomainPart($this->lexer);
-        $this->warnings = new \SplObjectStorage();
     }
 
     /**
@@ -57,6 +78,9 @@ class EmailParser
         return array('local' => $this->localPart, 'domain' => $this->domainPart);
     }
 
+    /**
+     * @return Warning\Warning[]
+     */
     public function getWarnings()
     {
         $localPartWarnings = $this->localPartParser->getWarnings();
@@ -68,11 +92,17 @@ class EmailParser
         return $this->warnings;
     }
 
+    /**
+     * @return string
+     */
     public function getParsedDomainPart()
     {
         return $this->domainPart;
     }
 
+    /**
+     * @param string $email
+     */
     protected function setParts($email)
     {
         $parts = explode('@', $email);
@@ -80,6 +110,9 @@ class EmailParser
         $this->localPart = $parts[0];
     }
 
+    /**
+     * @return bool
+     */
     protected function hasAtToken()
     {
         $this->lexer->moveNext();

src/EmailValidator.php

@@ -13,12 +13,12 @@ class EmailValidator
     private $lexer;
 
     /**
-     * @var array
+     * @var Warning\Warning[]
      */
-    protected $warnings;
+    protected $warnings = [];
 
     /**
-     * @var InvalidEmail
+     * @var InvalidEmail|null
      */
     protected $error;
 
@@ -58,7 +58,7 @@ class EmailValidator
     }
 
     /**
-     * @return InvalidEmail
+     * @return InvalidEmail|null
      */
     public function getError()
     {

src/Exception/DomainAcceptsNoMail.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Egulias\EmailValidator\Exception;
+
+class DomainAcceptsNoMail extends InvalidEmail
+{
+    const CODE = 154;
+    const REASON = 'Domain accepts no mail (Null MX, RFC7505)';
+}

src/Exception/LocalOrReservedDomain.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Egulias\EmailValidator\Exception;
+
+class LocalOrReservedDomain extends InvalidEmail
+{
+    const CODE = 153;
+    const REASON = 'Local, mDNS or reserved domain (RFC2606, RFC6762)';
+}

src/Exception/UnclosedComment.php

@@ -5,5 +5,5 @@ namespace Egulias\EmailValidator\Exception;
 class UnclosedComment extends InvalidEmail
 {
     const CODE = 146;
-    const REASON = "No colosing comment token found";
+    const REASON = "No closing comment token found";
 }

src/Parser/DomainPart.php

@@ -35,6 +35,10 @@ use Egulias\EmailValidator\Warning\TLD;
 class DomainPart extends Parser
 {
     const DOMAIN_MAX_LENGTH = 254;
+
+    /**
+     * @var string
+     */
     protected $domainPart = '';
 
     public function parse($domainPart)
@@ -95,11 +99,18 @@ class DomainPart extends Parser
         }
     }
 
+    /**
+     * @return string
+     */
     public function getDomainPart()
     {
         return $this->domainPart;
     }
 
+    /**
+     * @param string $addressLiteral
+     * @param int $maxGroups
+     */
     public function checkIPV6Tag($addressLiteral, $maxGroups = 8)
     {
         $prev = $this->lexer->getPrevious();
@@ -143,6 +154,9 @@ class DomainPart extends Parser
         }
     }
 
+    /**
+     * @return string
+     */
     protected function doParseDomainPart()
     {
         $domain = '';
@@ -184,12 +198,15 @@ class DomainPart extends Parser
 
             $domain .= $this->lexer->token['value'];
             $this->lexer->moveNext();
+            if ($this->lexer->token['type'] === EmailLexer::S_SP) {
+                throw new CharNotAllowed();
+            }
         } while (null !== $this->lexer->token['type']);
 
         return $domain;
     }
 
-    private function checkNotAllowedChars($token)
+    private function checkNotAllowedChars(array $token)
     {
         $notAllowed = [EmailLexer::S_BACKSLASH => true, EmailLexer::S_SLASH=> true];
         if (isset($notAllowed[$token['type']])) {
@@ -197,6 +214,9 @@ class DomainPart extends Parser
         }
     }
 
+    /**
+     * @return string|false
+     */
     protected function parseDomainLiteral()
     {
         if ($this->lexer->isNextToken(EmailLexer::S_COLON)) {
@@ -213,6 +233,9 @@ class DomainPart extends Parser
         return $this->doParseDomainLiteral();
     }
 
+    /**
+     * @return string|false
+     */
     protected function doParseDomainLiteral()
     {
         $IPv6TAG = false;
@@ -280,6 +303,11 @@ class DomainPart extends Parser
         return $addressLiteral;
     }
 
+    /**
+     * @param string $addressLiteral
+     *
+     * @return string|false
+     */
     protected function checkIPV4Tag($addressLiteral)
     {
         $matchesIP  = array();
@@ -297,16 +325,17 @@ class DomainPart extends Parser
                 return false;
             }
             // Convert IPv4 part to IPv6 format for further testing
-            $addressLiteral = substr($addressLiteral, 0, $index) . '0:0';
+            $addressLiteral = substr($addressLiteral, 0, (int) $index) . '0:0';
         }
 
         return $addressLiteral;
     }
 
-    protected function checkDomainPartExceptions($prev)
+    protected function checkDomainPartExceptions(array $prev)
     {
         $invalidDomainTokens = array(
             EmailLexer::S_DQUOTE => true,
+            EmailLexer::S_SQUOTE => true,
             EmailLexer::S_SEMICOLON => true,
             EmailLexer::S_GREATERTHAN => true,
             EmailLexer::S_LOWERTHAN => true,
@@ -338,6 +367,9 @@ class DomainPart extends Parser
         }
     }
 
+    /**
+     * @return bool
+     */
     protected function hasBrackets()
     {
         if ($this->lexer->token['type'] !== EmailLexer::S_OPENBRACKET) {
@@ -353,7 +385,7 @@ class DomainPart extends Parser
         return true;
     }
 
-    protected function checkLabelLength($prev)
+    protected function checkLabelLength(array $prev)
     {
         if ($this->lexer->token['type'] === EmailLexer::S_DOT &&
             $prev['type'] === EmailLexer::GENERIC &&

src/Parser/LocalPart.php

@@ -5,7 +5,6 @@ namespace Egulias\EmailValidator\Parser;
 use Egulias\EmailValidator\Exception\DotAtEnd;
 use Egulias\EmailValidator\Exception\DotAtStart;
 use Egulias\EmailValidator\EmailLexer;
-use Egulias\EmailValidator\EmailValidator;
 use Egulias\EmailValidator\Exception\ExpectingAT;
 use Egulias\EmailValidator\Exception\ExpectingATEXT;
 use Egulias\EmailValidator\Exception\UnclosedQuotedString;
@@ -20,6 +19,7 @@ class LocalPart extends Parser
         $parseDQuote = true;
         $closingQuote = false;
         $openedParenthesis = 0;
+        $totalLength = 0;
 
         while ($this->lexer->token['type'] !== EmailLexer::S_AT && null !== $this->lexer->token['type']) {
             if ($this->lexer->token['type'] === EmailLexer::S_DOT && null === $this->lexer->getPrevious()['type']) {
@@ -35,12 +35,13 @@ class LocalPart extends Parser
                 $this->parseComments();
                 $openedParenthesis += $this->getOpenedParenthesis();
             }
+
             if ($this->lexer->token['type'] === EmailLexer::S_CLOSEPARENTHESIS) {
                 if ($openedParenthesis === 0) {
                     throw new UnopenedComment();
-                } else {
-                    $openedParenthesis--;
                 }
+
+                $openedParenthesis--;
             }
 
             $this->checkConsecutiveDots();
@@ -58,15 +59,18 @@ class LocalPart extends Parser
                 $this->parseFWS();
             }
 
+            $totalLength += strlen($this->lexer->token['value']);
             $this->lexer->moveNext();
         }
 
-        $prev = $this->lexer->getPrevious();
-        if (strlen($prev['value']) > LocalTooLong::LOCAL_PART_LENGTH) {
+        if ($totalLength > LocalTooLong::LOCAL_PART_LENGTH) {
             $this->warnings[LocalTooLong::CODE] = new LocalTooLong();
         }
     }
 
+    /**
+     * @return bool
+     */
     protected function parseDoubleQuote()
     {
         $parseAgain = true;
@@ -118,7 +122,10 @@ class LocalPart extends Parser
         return $parseAgain;
     }
 
-    protected function isInvalidToken($token, $closingQuote)
+    /**
+     * @param bool $closingQuote
+     */
+    protected function isInvalidToken(array $token, $closingQuote)
     {
         $forbidden = array(
             EmailLexer::S_COMMA,

src/Parser/Parser.php

@@ -21,8 +21,19 @@ use Egulias\EmailValidator\Warning\QuotedString;
 
 abstract class Parser
 {
+    /**
+     * @var array
+     */
     protected $warnings = [];
+
+    /**
+     * @var EmailLexer
+     */
     protected $lexer;
+
+    /**
+     * @var int
+     */
     protected $openedParenthesis = 0;
 
     public function __construct(EmailLexer $lexer)
@@ -30,11 +41,17 @@ abstract class Parser
         $this->lexer = $lexer;
     }
 
+    /**
+     * @return \Egulias\EmailValidator\Warning\Warning[]
+     */
     public function getWarnings()
     {
         return $this->warnings;
     }
 
+    /**
+     * @param string $str
+     */
     abstract public function parse($str);
 
     /** @return int */
@@ -80,6 +97,9 @@ abstract class Parser
         }
     }
 
+    /**
+     * @return bool
+     */
     protected function isUnclosedComment()
     {
         try {
@@ -122,6 +142,9 @@ abstract class Parser
         }
     }
 
+    /**
+     * @return bool
+     */
     protected function isFWS()
     {
         if ($this->escaped()) {
@@ -140,11 +163,14 @@ abstract class Parser
         return false;
     }
 
+    /**
+     * @return bool
+     */
     protected function escaped()
     {
         $previous = $this->lexer->getPrevious();
 
-        if ($previous['type'] === EmailLexer::S_BACKSLASH
+        if ($previous && $previous['type'] === EmailLexer::S_BACKSLASH
             &&
             $this->lexer->token['type'] !== EmailLexer::GENERIC
         ) {
@@ -154,6 +180,9 @@ abstract class Parser
         return false;
     }
 
+    /**
+     * @return bool
+     */
     protected function warnEscaping()
     {
         if ($this->lexer->token['type'] !== EmailLexer::S_BACKSLASH) {
@@ -174,6 +203,11 @@ abstract class Parser
 
     }
 
+    /**
+     * @param bool $hasClosingQuote
+     *
+     * @return bool
+     */
     protected function checkDQUOTE($hasClosingQuote)
     {
         if ($this->lexer->token['type'] !== EmailLexer::S_DQUOTE) {

src/Validation/DNSCheckValidation.php

@@ -0,0 +1,166 @@
+<?php
+
+namespace Egulias\EmailValidator\Validation;
+
+use Egulias\EmailValidator\EmailLexer;
+use Egulias\EmailValidator\Exception\InvalidEmail;
+use Egulias\EmailValidator\Exception\LocalOrReservedDomain;
+use Egulias\EmailValidator\Exception\DomainAcceptsNoMail;
+use Egulias\EmailValidator\Warning\NoDNSMXRecord;
+use Egulias\EmailValidator\Exception\NoDNSRecord;
+
+class DNSCheckValidation implements EmailValidation
+{
+    /**
+     * @var array
+     */
+    private $warnings = [];
+
+    /**
+     * @var InvalidEmail|null
+     */
+    private $error;
+
+    /**
+     * @var array
+     */
+    private $mxRecords = [];
+
+
+    public function __construct()
+    {
+        if (!function_exists('idn_to_ascii')) {
+            throw new \LogicException(sprintf('The %s class requires the Intl extension.', __CLASS__));
+        }
+    }
+
+    public function isValid($email, EmailLexer $emailLexer)
+    {
+        // use the input to check DNS if we cannot extract something similar to a domain
+        $host = $email;
+
+        // Arguable pattern to extract the domain. Not aiming to validate the domain nor the email
+        if (false !== $lastAtPos = strrpos($email, '@')) {
+            $host = substr($email, $lastAtPos + 1);
+        }
+
+        // Get the domain parts
+        $hostParts = explode('.', $host);
+
+        // Reserved Top Level DNS Names (https://tools.ietf.org/html/rfc2606#section-2),
+        // mDNS and private DNS Namespaces (https://tools.ietf.org/html/rfc6762#appendix-G)
+        $reservedTopLevelDnsNames = [
+            // Reserved Top Level DNS Names
+            'test',
+            'example',
+            'invalid',
+            'localhost',
+
+            // mDNS
+            'local',
+
+            // Private DNS Namespaces
+            'intranet',
+            'internal',
+            'private',
+            'corp',
+            'home',
+            'lan',
+        ];
+
+        $isLocalDomain = count($hostParts) <= 1;
+        $isReservedTopLevel = in_array($hostParts[(count($hostParts) - 1)], $reservedTopLevelDnsNames, true);
+
+        // Exclude reserved top level DNS names
+        if ($isLocalDomain || $isReservedTopLevel) {
+            $this->error = new LocalOrReservedDomain();
+            return false;
+        }
+
+        return $this->checkDns($host);
+    }
+
+    public function getError()
+    {
+        return $this->error;
+    }
+
+    public function getWarnings()
+    {
+        return $this->warnings;
+    }
+
+    /**
+     * @param string $host
+     *
+     * @return bool
+     */
+    protected function checkDns($host)
+    {
+        $variant = INTL_IDNA_VARIANT_UTS46;
+
+        $host = rtrim(idn_to_ascii($host, IDNA_DEFAULT, $variant), '.') . '.';
+
+        return $this->validateDnsRecords($host);
+    }
+
+
+    /**
+     * Validate the DNS records for given host.
+     *
+     * @param string $host A set of DNS records in the format returned by dns_get_record.
+     *
+     * @return bool True on success.
+     */
+    private function validateDnsRecords($host)
+    {
+        // Get all MX, A and AAAA DNS records for host
+        // Using @ as workaround to fix https://bugs.php.net/bug.php?id=73149
+        $dnsRecords = @dns_get_record($host, DNS_MX + DNS_A + DNS_AAAA);
+
+
+        // No MX, A or AAAA DNS records
+        if (empty($dnsRecords)) {
+            $this->error = new NoDNSRecord();
+            return false;
+        }
+
+        // For each DNS record
+        foreach ($dnsRecords as $dnsRecord) {
+            if (!$this->validateMXRecord($dnsRecord)) {
+                return false;
+            }
+        }
+
+        // No MX records (fallback to A or AAAA records)
+        if (empty($this->mxRecords)) {
+            $this->warnings[NoDNSMXRecord::CODE] = new NoDNSMXRecord();
+        }
+
+        return true;
+    }
+
+    /**
+     * Validate an MX record
+     *
+     * @param array $dnsRecord Given DNS record.
+     *
+     * @return bool True if valid.
+     */
+    private function validateMxRecord($dnsRecord)
+    {
+        if ($dnsRecord['type'] !== 'MX') {
+            return true;
+        }
+
+        // "Null MX" record indicates the domain accepts no mail (https://tools.ietf.org/html/rfc7505)
+        if (empty($dnsRecord['target']) || $dnsRecord['target'] === '.') {
+            $this->error = new DomainAcceptsNoMail();
+            return false;
+        }
+
+        $this->mxRecords[] = $dnsRecord;
+
+        return true;
+    }
+}

src/Validation/Exception/EmptyValidationList.php

@@ -6,6 +6,9 @@ use Exception;
 
 class EmptyValidationList extends \InvalidArgumentException
 {
+    /**
+    * @param int $code
+    */
     public function __construct($code = 0, Exception $previous = null)
     {
         parent::__construct("Empty validation list is not allowed", $code, $previous);

src/Validation/MultipleErrors.php

@@ -9,16 +9,22 @@ class MultipleErrors extends InvalidEmail
     const CODE = 999;
     const REASON = "Accumulated errors for multiple validations";
     /**
-     * @var array
+     * @var InvalidEmail[]
      */
     private $errors = [];
 
+    /**
+     * @param InvalidEmail[] $errors
+     */
     public function __construct(array $errors)
     {
         $this->errors = $errors;
         parent::__construct();
     }
 
+    /**
+     * @return InvalidEmail[]
+     */
     public function getErrors()
     {
         return $this->errors;

src/Validation/MultipleValidationWithAnd.php

@@ -30,12 +30,12 @@ class MultipleValidationWithAnd implements EmailValidation
     private $warnings = [];
 
     /**
-     * @var MultipleErrors
+     * @var MultipleErrors|null
      */
     private $error;
 
     /**
-     * @var bool
+     * @var int
      */
     private $mode;
 
@@ -79,6 +79,12 @@ class MultipleValidationWithAnd implements EmailValidation
         return $result;
     }
 
+    /**
+     * @param \Egulias\EmailValidator\Exception\InvalidEmail|null $possibleError
+     * @param \Egulias\EmailValidator\Exception\InvalidEmail[] $errors
+     *
+     * @return \Egulias\EmailValidator\Exception\InvalidEmail[]
+     */
     private function addNewError($possibleError, array $errors)
     {
         if (null !== $possibleError) {
@@ -88,6 +94,11 @@ class MultipleValidationWithAnd implements EmailValidation
         return $errors;
     }
 
+    /**
+     * @param bool $result
+     *
+     * @return bool
+     */
     private function shouldStop($result)
     {
         return !$result && $this->mode === self::STOP_ON_ERROR;

src/Validation/NoRFCWarningsValidation.php

@@ -9,7 +9,7 @@ use Egulias\EmailValidator\Validation\Error\RFCWarnings;
 class NoRFCWarningsValidation extends RFCValidation
 {
     /**
-     * @var InvalidEmail
+     * @var InvalidEmail|null
      */
     private $error;
 

src/Validation/RFCValidation.php

@@ -9,7 +9,7 @@ use Egulias\EmailValidator\Exception\InvalidEmail;
 class RFCValidation implements EmailValidation
 {
     /**
-     * @var EmailParser
+     * @var EmailParser|null
      */
     private $parser;
 
@@ -19,7 +19,7 @@ class RFCValidation implements EmailValidation
     private $warnings = [];
 
     /**
-     * @var InvalidEmail
+     * @var InvalidEmail|null
      */
     private $error;
 

src/Validation/SpoofCheckValidation.php

@@ -10,7 +10,7 @@ use \Spoofchecker;
 class SpoofCheckValidation implements EmailValidation
 {
     /**
-     * @var InvalidEmail
+     * @var InvalidEmail|null
      */
     private $error;
 
@@ -21,6 +21,9 @@ class SpoofCheckValidation implements EmailValidation
         }
     }
 
+    /**
+     * @psalm-suppress InvalidArgument
+     */
     public function isValid($email, EmailLexer $emailLexer)
     {
         $checker = new Spoofchecker();
@@ -33,6 +36,9 @@ class SpoofCheckValidation implements EmailValidation
         return $this->error === null;
     }
 
+    /**
+     * @return InvalidEmail|null
+     */
     public function getError()
     {
         return $this->error;

src/Warning/QuotedPart.php

@@ -6,6 +6,10 @@ class QuotedPart extends Warning
 {
     const CODE = 36;
 
+    /**
+     * @param scalar $prevToken
+     * @param scalar $postToken
+     */
     public function __construct($prevToken, $postToken)
     {
         $this->message = "Deprecated Quoted String found between $prevToken and $postToken";

src/Warning/QuotedString.php

@@ -6,6 +6,10 @@ class QuotedString extends Warning
 {
     const CODE = 11;
 
+    /**
+     * @param scalar $prevToken
+     * @param scalar $postToken
+     */
     public function __construct($prevToken, $postToken)
     {
         $this->message = "Quoted String found between $prevToken and $postToken";

src/Warning/Warning.php

@@ -5,19 +5,36 @@ namespace Egulias\EmailValidator\Warning;
 abstract class Warning
 {
     const CODE = 0;
-    protected $message;
-    protected $rfcNumber;
 
+    /**
+     * @var string
+     */
+    protected $message = '';
+
+    /**
+     * @var int
+     */
+    protected $rfcNumber = 0;
+
+    /**
+     * @return string
+     */
     public function message()
     {
         return $this->message;
     }
 
+    /**
+     * @return int
+     */
     public function code()
     {
         return self::CODE;
     }
 
+    /**
+     * @return int
+     */
     public function RFCNumber()
     {
         return $this->rfcNumber;

tests/EmailValidator/EmailLexerTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Egulias\Tests\EmailValidator;
+namespace Egulias\EmailValidator\Tests\EmailValidator;
 
 use Egulias\EmailValidator\EmailLexer;
 use PHPUnit\Framework\TestCase;
@@ -138,6 +138,7 @@ class EmailLexerTests extends TestCase
             array(":", EmailLexer::S_COLON),
             array(".", EmailLexer::S_DOT),
             array("\"", EmailLexer::S_DQUOTE),
+            array("'", EmailLexer::S_SQUOTE),
             array("-", EmailLexer::S_HYPHEN),
             array("\\", EmailLexer::S_BACKSLASH),
             array("/", EmailLexer::S_SLASH),

tests/EmailValidator/EmailValidatorTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Egulias\Tests\EmailValidator;
+namespace Egulias\EmailValidator\Tests\EmailValidator;
 
 use Egulias\EmailValidator\EmailValidator;
 use Egulias\EmailValidator\Validation\EmailValidation;

tests/EmailValidator/Validation/DNSCheckValidationTest.php

@@ -0,0 +1,109 @@
+<?php
+
+namespace Egulias\EmailValidator\Tests\EmailValidator\Validation;
+
+use Egulias\EmailValidator\EmailLexer;
+use Egulias\EmailValidator\Exception\NoDNSRecord;
+use Egulias\EmailValidator\Exception\LocalOrReservedDomain;
+use Egulias\EmailValidator\Exception\DomainAcceptsNoMail;
+use Egulias\EmailValidator\Validation\DNSCheckValidation;
+use Egulias\EmailValidator\Warning\NoDNSMXRecord;
+use PHPUnit\Framework\TestCase;
+
+class DNSCheckValidationTest extends TestCase
+{
+    public function validEmailsProvider()
+    {
+        return [
+            // dot-atom
+            ['Abc@ietf.org'],
+            ['ABC@ietf.org'],
+            ['Abc.123@ietf.org'],
+            ['user+mailbox/department=shipping@ietf.org'],
+            ['!#$%&\'*+-/=?^_`.{|}~@ietf.org'],
+
+            // quoted string
+            ['"Abc@def"@ietf.org'],
+            ['"Fred\ Bloggs"@ietf.org'],
+            ['"Joe.\\Blow"@ietf.org'],
+
+            // unicode
+            ['ñandu.cl'],
+        ];
+    }
+
+    public function localOrReservedEmailsProvider()
+    {
+        return [
+            // Reserved Top Level DNS Names
+            ['test'],
+            ['example'],
+            ['invalid'],
+            ['localhost'],
+
+            // mDNS
+            ['local'],
+
+            // Private DNS Namespaces
+            ['intranet'],
+            ['internal'],
+            ['private'],
+            ['corp'],
+            ['home'],
+            ['lan'],
+        ];
+    }
+
+    /**
+     * @dataProvider validEmailsProvider
+     */
+    public function testValidDNS($validEmail)
+    {
+        $validation = new DNSCheckValidation();
+        $this->assertTrue($validation->isValid($validEmail, new EmailLexer()));
+    }
+
+    public function testInvalidDNS()
+    {
+        $validation = new DNSCheckValidation();
+        $this->assertFalse($validation->isValid("example@invalid.example.com", new EmailLexer()));
+    }
+
+    /**
+     * @dataProvider localOrReservedEmailsProvider
+     */
+    public function testLocalOrReservedDomainError($localOrReservedEmails)
+    {
+        $validation = new DNSCheckValidation();
+        $expectedError = new LocalOrReservedDomain();
+        $validation->isValid($localOrReservedEmails, new EmailLexer());
+        $this->assertEquals($expectedError, $validation->getError());
+    }
+
+    public function testDomainAcceptsNoMailError()
+    {
+        $validation = new DNSCheckValidation();
+        $expectedError = new DomainAcceptsNoMail();
+        $isValidResult = $validation->isValid("nullmx@example.com", new EmailLexer());
+        $this->assertEquals($expectedError, $validation->getError());
+        $this->assertFalse($isValidResult);
+    }
+
+    /*
+    public function testDNSWarnings()
+    {
+        $validation = new DNSCheckValidation();
+        $expectedWarnings = [NoDNSMXRecord::CODE => new NoDNSMXRecord()];
+        $validation->isValid("example@invalid.example.com", new EmailLexer());
+        $this->assertEquals($expectedWarnings, $validation->getWarnings());
+    }
+    */
+
+    public function testNoDNSError()
+    {
+        $validation = new DNSCheckValidation();
+        $expectedError = new NoDNSRecord();
+        $validation->isValid("example@invalid.example.com", new EmailLexer());
+        $this->assertEquals($expectedError, $validation->getError());
+    }
+}

tests/EmailValidator/Validation/IsEmailFunctionTests.php

@@ -1,12 +1,11 @@
 <?php
 
-namespace Egulias\Tests\EmailValidator\Validation;
+namespace Egulias\EmailValidator\Tests\EmailValidator\Validation;
 
 use Egulias\EmailValidator\EmailValidator;
 use Egulias\EmailValidator\Validation\DNSCheckValidation;
 use Egulias\EmailValidator\Validation\MultipleValidationWithAnd;
 use Egulias\EmailValidator\Validation\NoRFCWarningsValidation;
-use Egulias\EmailValidator\Validation\RFCValidation;
 use PHPUnit\Framework\TestCase;
 
 class IsEmailFunctionTests extends TestCase
@@ -28,7 +27,7 @@ class IsEmailFunctionTests extends TestCase
 
     public function isEmailTestSuite()
     {
-        $testSuite = dirname(__FILE__) . '/../../resources/is_email_tests.xml';
+        $testSuite = __DIR__ . '/../../resources/is_email_tests.xml';
         $document = new \DOMDocument();
         $document->load($testSuite);
         $elements = $document->getElementsByTagName('test');

tests/EmailValidator/Validation/MultipleValidationWithAndTest.php

@@ -1,15 +1,13 @@
 <?php
 
-namespace Egulias\Tests\EmailValidator\Validation;
+namespace Egulias\EmailValidator\Tests\EmailValidator\Validation;
 
 use Egulias\EmailValidator\EmailLexer;
-use Egulias\EmailValidator\EmailValidator;
 use Egulias\EmailValidator\Exception\CommaInDomain;
 use Egulias\EmailValidator\Exception\NoDomainPart;
 use Egulias\EmailValidator\Validation\EmailValidation;
 use Egulias\EmailValidator\Validation\MultipleErrors;
 use Egulias\EmailValidator\Validation\MultipleValidationWithAnd;
-use Egulias\EmailValidator\Validation\NoRFCWarningsValidation;
 use Egulias\EmailValidator\Validation\RFCValidation;
 use Egulias\EmailValidator\Warning\AddressLiteral;
 use Egulias\EmailValidator\Warning\DomainLiteral;
@@ -20,7 +18,7 @@ class MultipleValidationWithAndTest extends TestCase
     public function testUsesAndLogicalOperation()
     {
         $lexer = new EmailLexer();
-        $validationTrue = $this->getMockBuilder("Egulias\\EmailValidator\\Validation\\EmailValidation")->getMock();
+        $validationTrue = $this->getMockBuilder(EmailValidation::class)->getMock();
         $validationTrue->expects($this->any())->method("isValid")->willReturn(true);
         $validationTrue->expects($this->any())->method("getWarnings")->willReturn([]);
         $validationFalse = $this->getMockBuilder(EmailValidation::class)->getMock();
@@ -62,7 +60,7 @@ class MultipleValidationWithAndTest extends TestCase
         $expectedResult = array_merge($warnings1, $warnings2);
 
         $lexer = new EmailLexer();
-        $validation1 = $this->getMockBuilder("Egulias\\EmailValidator\\Validation\\EmailValidation")->getMock();
+        $validation1 = $this->getMockBuilder(EmailValidation::class)->getMock();
         $validation1->expects($this->any())->method("isValid")->willReturn(true);
         $validation1->expects($this->once())->method("getWarnings")->willReturn($warnings1);
 

tests/EmailValidator/Validation/NoRFCWarningsValidationTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Egulias\Tests\EmailValidator\Validation;
+namespace Egulias\EmailValidator\Tests\EmailValidator\Validation;
 
 use Egulias\EmailValidator\EmailLexer;
 use Egulias\EmailValidator\Exception\NoDomainPart;

tests/EmailValidator/Validation/RFCValidationTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Egulias\Tests\EmailValidator\Validation;
+namespace Egulias\EmailValidator\Tests\EmailValidator\Validation;
 
 use Egulias\EmailValidator\EmailLexer;
 use Egulias\EmailValidator\Validation\RFCValidation;
@@ -104,7 +104,7 @@ class RFCValidationTest extends TestCase
 
     public function testInvalidUTF8Email()
     {
-        $email     = "\x80\x81\x82@\x83\x84\x85.\x86\x87\x88";
+        $email = "\x80\x81\x82@\x83\x84\x85.\x86\x87\x88";
         $this->assertFalse($this->validator->isValid($email, $this->lexer));
     }
 
@@ -167,6 +167,8 @@ class RFCValidationTest extends TestCase
             ['test@email<'],
             ['test@email{'],
             ['test@ '],
+            ['test@example.com []'],
+            ["test@example.com'"],
         ];
     }
 
@@ -211,6 +213,7 @@ class RFCValidationTest extends TestCase
             [new CRNoLF(), "example@exa\rmple.co.uk"],
             [new CRNoLF(), "example@[\r]"],
             [new CRNoLF(), "exam\rple@example.co.uk"],
+            [new ExpectingATEXT(), "test@example.com'"],
         ];
     }
 
@@ -265,6 +268,10 @@ class RFCValidationTest extends TestCase
                 [LocalTooLong::CODE,],
                 'too_long_localpart_too_long_localpart_too_long_localpart_too_long_localpart@invalid.example.com'
             ],
+            [
+                [LocalTooLong::CODE],
+                'too_long_localpart_too_long_localpart_123_too_long_localpart_too_long_localpart@example.com'
+            ],
             [
                 [LabelTooLong::CODE,],
                 'example@toolonglocalparttoolonglocalparttoolonglocalparttoolonglocalpart.co.uk'

tests/EmailValidator/Validation/SpoofCheckValidationTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Egulias\Tests\EmailValidator\Validation;
+namespace Egulias\EmailValidator\Tests\EmailValidator\Validation;
 
 use Egulias\EmailValidator\EmailLexer;
 use Egulias\EmailValidator\Validation\SpoofCheckValidation;