Add new sniff for various integer types.

Checks for:
* binary integers which were introduced in PHP 5.4
* invalid binary integers
* invalid octal integers which were truncated prior to PHP 7 (warning) and give a parse error in 7 (error).
* hexadecimal numeric strings for which the type juggling behaviour and recognition as numeric was inconsistent prior to PHP 7 (warning) and are no longer treated as numeric in PHP 7+(error).

Includes unit tests.

Closes PHPCompatibility#55

Sniffs/PHP/ValidIntegersSniff.php

@@ -0,0 +1,208 @@
+<?php
+/**
+ * PHPCompatibility_Sniffs_PHP_ValidIntegersSniff.
+ *
+ * @category  PHP
+ * @package   PHPCompatibility
+ * @author    Juliette Reinders Folmer <phpcompatibility_nospam@adviesenzo.nl>
+ */
+
+/**
+ * PHPCompatibility_Sniffs_PHP_ValidIntegersSniff.
+ *
+ * @category  PHP
+ * @package   PHPCompatibility
+ * @author    Juliette Reinders Folmer <phpcompatibility_nospam@adviesenzo.nl>
+ */
+class PHPCompatibility_Sniffs_PHP_ValidIntegersSniff extends PHPCompatibility_Sniff
+{
+    protected $isLowPHPVersion = false;
+
+    /**
+     * Returns an array of tokens this test wants to listen for.
+     *
+     * @return array
+     */
+    public function register()
+    {
+        $this->isLowPHPVersion = version_compare(phpversion(), '5.4', '<');
+
+        return array(
+                T_LNUMBER, // Binary, octal integers.
+                T_CONSTANT_ENCAPSED_STRING, // Hex numeric string.
+               );
+
+    }//end register()
+
+
+    /**
+     * Processes this test, when one of its tokens is encountered.
+     *
+     * @param PHP_CodeSniffer_File $phpcsFile The file being scanned.
+     * @param int                  $stackPtr  The position of the current token in
+     *                                        the stack.
+     *
+     * @return void
+     */
+    public function process(PHP_CodeSniffer_File $phpcsFile, $stackPtr)
+    {
+        $tokens = $phpcsFile->getTokens();
+        $token  = $tokens[$stackPtr];
+
+        if ($this->couldBeBinaryInteger($tokens, $stackPtr) === true) {
+            if ($this->supportsBelow('5.3')) {
+                $error = 'Binary integer literals were not present in PHP version 5.3 or earlier. Found: %s';
+                if ($this->isLowPHPVersion === false) {
+                    $data = array($token['content']);
+                }
+                else {
+                    $data = array($this->getBinaryInteger($phpcsFile, $tokens, $stackPtr));
+                }
+                $phpcsFile->addError($error, $stackPtr, 'BinaryIntegerFound', $data);
+            }
+
+            if ($this->isInvalidBinaryInteger($tokens, $stackPtr) === true) {
+                $error = 'Invalid binary integer detected. Found: %s';
+                $data  = array($this->getBinaryInteger($phpcsFile, $tokens, $stackPtr));
+                $phpcsFile->addError($error, $stackPtr, 'InvalidBinaryIntegerFound', $data);
+            }
+            return;
+        }
+
+        $data = array( $token['content'] );
+        if ($this->isInvalidOctalInteger($tokens, $stackPtr) === true) {
+            $error   = 'Invalid octal integer detected. Prior to PHP 7 this would lead to a truncated number. From PHP 7 onwards this causes a parse error. Found: %s';
+            $isError = $this->supportsAbove('7.0');
+
+            if ($isError === true) {
+                $phpcsFile->addError($error, $stackPtr, 'InvalidOctalIntegerFound', $data);
+            } else {
+                $phpcsFile->addWarning($error, $stackPtr, 'InvalidOctalIntegerFound', $data);
+            }
+
+            return;
+        }
+
+        if ($this->isHexidecimalNumericString($tokens, $stackPtr) === true) {
+            $error   = 'The behaviour of hexadecimal numeric strings was inconsistent prior to PHP 7 and support has been removed in PHP 7. Found: %s';
+            $isError = $this->supportsAbove('7.0');
+
+            if ($isError === true) {
+                $phpcsFile->addError($error, $stackPtr, 'HexNumericStringFound', $data);
+            } else {
+                $phpcsFile->addWarning($error, $stackPtr, 'HexNumericStringFound', $data);
+            }
+            return;
+        }
+
+    }//end process()
+
+
+    /**
+     * Could the current token an potentially be a binary integer ?
+     *
+     * @param array $token    Token stack.
+     * @param int   $stackPtr The current position in the token stack.
+     *
+     * @return bool
+     */
+    private function couldBeBinaryInteger($tokens, $stackPtr) {
+        $token = $tokens[$stackPtr];
+
+        if ($token['code'] !== T_LNUMBER) {
+            return false;
+        }
+
+        if ($this->isLowPHPVersion === false) {
+            return (preg_match('`^0b[0-1]+$`D', $token['content']) === 1);
+        }
+        // Pre-5.4, binary strings are tokenized as T_LNUMBER (0) + T_STRING ("b01010101").
+        // At this point, we don't yet care whether it's a valid binary int, that's a separate check.
+        else {
+            return($token['content'] === '0' && $tokens[$stackPtr+1]['code'] === T_STRING && preg_match('`^b[0-9]+$`D', $tokens[$stackPtr+1]['content']) === 1);
+        }
+    }
+
+    /**
+     * Is the current token an invalid binary integer ?
+     *
+     * @param array $token    Token stack.
+     * @param int   $stackPtr The current position in the token stack.
+     *
+     * @return bool
+     */
+    private function isInvalidBinaryInteger($tokens, $stackPtr) {
+        if ($this->couldBeBinaryInteger($tokens, $stackPtr) === false) {
+            return false;
+        }
+
+        if ($this->isLowPHPVersion === false) {
+            // If it's an invalid binary int, the token will be split into two T_LNUMBER tokens.
+            return ($tokens[$stackPtr+1]['code'] === T_LNUMBER);
+        }
+        else {
+            return (preg_match('`^b[0-1]+$`D', $tokens[$stackPtr+1]['content']) === 0);
+        }
+    }
+
+    /**
+     * Retrieve the content of the tokens which together look like a binary integer.
+     *
+     * @param PHP_CodeSniffer_File $phpcsFile The file being scanned.
+     * @param array                $token     Token stack.
+     * @param int                  $stackPtr  The position of the current token in
+     *                                        the stack.
+     *
+     * @return string
+     */
+    private function getBinaryInteger(PHP_CodeSniffer_File $phpcsFile, $tokens, $stackPtr) {
+        $length = 2; // PHP < 5.4 T_LNUMBER + T_STRING
+
+        if ($this->isLowPHPVersion === false) {
+            $i = $stackPtr;
+            while ($tokens[$i]['code'] === T_LNUMBER) {
+                $i++;
+            }
+            $length = ($i - $stackPtr);
+        }
+
+        return $phpcsFile->getTokensAsString($stackPtr, $length);
+    }
+
+    /**
+     * Is the current token an invalid octal integer ?
+     *
+     * @param array $token    Token stack.
+     * @param int   $stackPtr The current position in the token stack.
+     *
+     * @return bool
+     */
+    private function isInvalidOctalInteger($tokens, $stackPtr) {
+        $token = $tokens[$stackPtr];
+
+        if ($token['code'] === T_LNUMBER && preg_match('`^0[0-7]*[8-9]+[0-9]*$`D', $token['content']) === 1) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Is the current token a hexidecimal numeric string ?
+     *
+     * @param array $token    Token stack.
+     * @param int   $stackPtr The current position in the token stack.
+     *
+     * @return bool
+     */
+    private function isHexidecimalNumericString($tokens, $stackPtr) {
+        $token = $tokens[$stackPtr];
+
+        if ($token['code'] === T_CONSTANT_ENCAPSED_STRING && preg_match('`^([\'"])0x[a-f0-9]+\1$`iD', $token['content']) === 1) {
+            return true;
+        }
+
+        return false;
+    }
+
+}//end class

Tests/Sniffs/PHP/ValidIntegersSniffTest.php

@@ -0,0 +1,168 @@
+<?php
+/**
+ * Valid Integers Sniff test file
+ *
+ * @package PHPCompatibility
+ */
+
+
+/**
+ * Valid Integers Sniff tests
+ *
+ * @uses    BaseSniffTest
+ * @package PHPCompatibility
+ * @author  Juliette Reinders Folmer <phpcompatibility_nospam@adviesenzo.nl>
+ */
+class ValidIntegersSniffTest extends BaseSniffTest
+{
+
+    const TEST_FILE = 'sniff-examples/valid_integers.php';
+
+    /**
+     * Sniffed file
+     *
+     * @var PHP_CodeSniffer_File
+     */
+    protected $_sniffFile;
+
+    /**
+     * setUp
+     *
+     * @return void
+     */
+    public function setUp()
+    {
+        parent::setUp();
+
+        $this->_sniffFile = $this->sniffFile(self::TEST_FILE);
+    }
+
+
+    /**
+     * testBinaryInteger
+     *
+     * @group ValidIntegers
+     *
+     * @dataProvider dataBinaryInteger
+     *
+     * @param int    $line  Line number where the error should occur.
+     * @param string $octal (Start of) Binary number as a string.
+     * @param bool   $testNoViolation Whether or not to test for noViolation.
+     *               Defaults to true. Set to false if another error is
+     *               expected on the same line (invalid binary)
+     *
+     * @return void
+     */
+    public function testBinaryInteger($line, $binary, $testNoViolation = true)
+    {
+
+        $file = $this->sniffFile(self::TEST_FILE, '5.3');
+        $this->assertError($file, $line, 'Binary integer literals were not present in PHP version 5.3 or earlier. Found: ' . $binary);
+
+
+		if ($testNoViolation === true) {
+	        $file = $this->sniffFile(self::TEST_FILE, '5.4');
+	        $this->assertNoViolation($file, $line);
+		}
+    }
+
+    /**
+     * dataBinaryInteger
+     *
+     * @see testBinaryInteger()
+     *
+     * @return array
+     */
+    public function dataBinaryInteger() {
+        return array(
+            array(3, '0b001001101', true),
+            array(4, '0b01', false),
+        );
+    }
+
+
+    /**
+     * testInvalidBinaryInteger
+     *
+     * @group ValidIntegers
+     *
+     * @return void
+     */
+    public function testInvalidBinaryInteger()
+    {
+        $this->assertError($this->_sniffFile, 4, 'Invalid binary integer detected. Found: 0b0123456');
+    }
+
+
+    /**
+     * testInvalidOctalInteger
+     *
+     * @group ValidIntegers
+     *
+     * @dataProvider dataInvalidOctalInteger
+     *
+     * @param int    $line  Line number where the error should occur.
+     * @param string $octal Octal number as a string.
+     *
+     * @return void
+     */
+    public function testInvalidOctalInteger($line, $octal)
+    {
+        $error = 'Invalid octal integer detected. Prior to PHP 7 this would lead to a truncated number. From PHP 7 onwards this causes a parse error. Found: ' . $octal;
+
+        $file = $this->sniffFile(self::TEST_FILE, '5.4');
+        $this->assertWarning($file, $line, $error);
+
+        $file = $this->sniffFile(self::TEST_FILE, '7.0');
+        $this->assertError($file, $line, $error);
+    }
+
+    /**
+     * dataInvalidOctalInteger
+     *
+     * @see testInvalidOctalInteger()
+     *
+     * @return array
+     */
+    public function dataInvalidOctalInteger() {
+        return array(
+            array(7, '08'),
+            array(8, '038'),
+            array(9, '091'),
+        );
+    }
+
+
+    /**
+     * testValidOctalInteger
+     *
+     * @group ValidIntegers
+     *
+     * @return void
+     */
+    public function testValidOctalInteger() {
+        $this->assertNoViolation($this->_sniffFile, 6);
+    }
+
+
+    /**
+     * testHexNumericString
+     *
+     * @group ValidIntegers
+     *
+     * @return void
+     */
+    public function testHexNumericString()
+    {
+        $error = 'The behaviour of hexadecimal numeric strings was inconsistent prior to PHP 7 and support has been removed in PHP 7. Found: \'0xaa78b5\'';
+
+        $file = $this->sniffFile(self::TEST_FILE, '5.0');
+        $this->assertWarning($file, 11, $error);
+        $this->assertNoViolation($file, 12);
+
+        $file = $this->sniffFile(self::TEST_FILE, '7.0');
+        $this->assertError($file, 11, $error);
+        $this->assertNoViolation($file, 12);
+    }
+
+}

Tests/sniff-examples/valid_integers.php

@@ -0,0 +1,12 @@
+<?php
+
+$binary = 0b001001101;
+$invalidBinary = 0b0123456;
+
+$validOctal = 061; // Ok.
+$invalidOctal = 08;
+$invalidOctal = 038;
+$invalidOctal = 091;
+
+$hex = '0xaa78b5';
+$hex = 'aa78b5'; // Ok.