Find invalid chars in the VAT number and throw an exception if there …

…are some

Fix #19

README.md

@@ -105,7 +105,8 @@ if ($vatCalculator->shouldCollectEuVat('DE')) {
 
 To validate your customers VAT numbers, you can use the `isValidVatNumber` method.
 The VAT number should be in a format specified by the [VIES](https://ec.europa.eu/taxation_customs/vies/faqvies.do#item_11).
-The given VAT numbers will be truncated and non relevant characters / whitespace will automatically be removed.
+The given VAT numbers will be truncated and non relevant characters (`-`, `.`, `,`, whitespace) will automatically be removed.
+If there are any invalid characters left, like non-latin letters for example, `InvalidCharsInVatNumberException` will be thrown.
 
 This service relies on a third party SOAP API provided by the EU. If, for whatever reason, this API is unavailable a `VatCheckUnavailableException` will be thrown.
 

composer.json

@@ -21,7 +21,7 @@
 	"require-dev": {
 		"php-parallel-lint/php-parallel-lint": "^1.2",
 		"php-parallel-lint/php-console-highlighter": "^0.5.0",
-		"phpstan/phpstan": "^0.12.42",
+		"phpstan/phpstan": "^0.12.44",
 		"phpunit/php-timer": "1.0.*",
 		"phpunit/phpunit": "4.7.*",
 		"spaze/coding-standard": "^0.0.3"

src/Exceptions/InvalidCharsInVatNumberException.php

@@ -0,0 +1,39 @@
+<?php
+declare(strict_types = 1);
+
+namespace Spaze\VatCalculator\Exceptions;
+
+use Throwable;
+
+class InvalidCharsInVatNumberException extends VatNumberException
+{
+
+	/** @var array<integer, string> */
+	private $invalidChars = [];
+
+
+	/**
+	 * @param array<integer, array{0: string, 1:integer}> $invalidChars
+	 * @param string $vatNumber
+	 * @param Throwable|null $previous
+	 */
+	public function __construct(array $invalidChars, string $vatNumber, Throwable $previous = null)
+	{
+		$chars = [];
+		foreach ($invalidChars as $invalidChar) {
+			$chars[] = sprintf('%s (0x%s) at offset %d', $invalidChar[0], bin2hex($invalidChar[0]), $invalidChar[1]);
+			$this->invalidChars[$invalidChar[1]] = $invalidChar[0];
+		}
+		parent::__construct("VAT number {$vatNumber} contains invalid characters: " . implode(', ', $chars), 0, $previous);
+	}
+
+
+	/**
+	 * @return array<integer, string> byte offset => character
+	 */
+	public function getInvalidChars(): array
+	{
+		return $this->invalidChars;
+	}
+
+}

src/VatCalculator.php

@@ -4,6 +4,7 @@
 namespace Spaze\VatCalculator;
 
 use DateTimeInterface;
+use Spaze\VatCalculator\Exceptions\InvalidCharsInVatNumberException;
 use Spaze\VatCalculator\Exceptions\UnsupportedCountryException;
 use Spaze\VatCalculator\Exceptions\VatCheckUnavailableException;
 use SoapClient;
@@ -129,6 +130,7 @@ public function getTaxRateForLocation(string $countryCode, ?string $postalCode,
 	 * @return bool
 	 * @throws VatCheckUnavailableException
 	 * @throws UnsupportedCountryException
+	 * @throws InvalidCharsInVatNumberException
 	 */
 	public function isValidVatNumber(string $vatNumber): bool
 	{
@@ -142,10 +144,18 @@ public function isValidVatNumber(string $vatNumber): bool
 	 * @return VatDetails
 	 * @throws VatCheckUnavailableException
 	 * @throws UnsupportedCountryException
+	 * @throws InvalidCharsInVatNumberException
 	 */
 	public function getVatDetails(string $vatNumber, ?string $requesterVatNumber = null): VatDetails
 	{
 		$vatNumber = str_replace([' ', "\xC2\xA0", "\xA0", '-', '.', ','], '', trim($vatNumber));
+
+		// Regex from https://ec.europa.eu/taxation_customs/vies/checkVatService.wsdl sans the quantifiers
+		$invalidChars = preg_split('/[0-9A-Za-z+*.]+/', $vatNumber, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_OFFSET_CAPTURE);
+		if ($invalidChars) {
+			throw new InvalidCharsInVatNumberException($invalidChars, $vatNumber);
+		}
+
 		$countryCode = substr($vatNumber, 0, 2);
 		$vatNumber = substr($vatNumber, 2);
 

tests/VatCalculatorTest.php

@@ -8,6 +8,7 @@
 use ReflectionClass;
 use SoapClient;
 use SoapFault;
+use Spaze\VatCalculator\Exceptions\InvalidCharsInVatNumberException;
 use Spaze\VatCalculator\Exceptions\UnsupportedCountryException;
 use Spaze\VatCalculator\Exceptions\VatCheckUnavailableException;
 use stdClass;
@@ -151,6 +152,13 @@ public function testValidateVatNumberThrowsExceptionOnInvalidCountry(): void
 	}
 
 
+	public function testValidateVatNumberThrowsExceptionOnInvalidChars(): void
+	{
+		$this->setExpectedException(InvalidCharsInVatNumberException::class, 'VAT number CY123Μ456_789 contains invalid characters: Μ (0xce9c) at offset 5, _ (0x5f) at offset 10');
+		$this->vatCalculator->isValidVatNumber('CY123Μ456_789');
+	}
+
+
 	public function testCanValidateValidVatNumberWithRequesterVatNumber()
 	{
 		$result = new stdClass();