From d2633f906626095aa328a11782e25ee533df79b6 Mon Sep 17 00:00:00 2001
From: jrfnl <jrfnl@users.noreply.github.com>
Date: Fri, 27 Mar 2020 09:41:22 +0100
Subject: [PATCH] :sparkles: PHP 7.4: New NewNumericLiteralSeparator sniff

New sniff to detect PHP 7.4 numeric literals with an underscore separator.

> Added support for underscore separators in numeric literals. Some examples:
>
>       6.674_083e-11; // float
>       299_792_458;   // decimal
>       0xCAFE_F00D;   // hexadecimal
>        0b0101_1111;   // binary

Refs:
* https://www.php.net/manual/en/migration74.new-features.php#migration74.new-features.core.numeric-literal-separator
* https://github.com/php/php-src/blob/8f4e24eeef7bd1c39fabf5bea016abb287a4c606/UPGRADING#L189-L196
* https://wiki.php.net/rfc/numeric_literal_separator
* https://github.com/php/php-src/pull/4165
* https://github.com/php/php-src/commit/f74109d9a4b1e4fbaeba4f68c8fc89950e19d265

Related to 808
---
 .../NewNumericLiteralSeparatorSniff.php       |  86 +++++++++++
 .../NewNumericLiteralSeparatorUnitTest.inc    |  41 +++++
 .../NewNumericLiteralSeparatorUnitTest.php    | 141 ++++++++++++++++++
 3 files changed, 268 insertions(+)
 create mode 100644 PHPCompatibility/Sniffs/Numbers/NewNumericLiteralSeparatorSniff.php
 create mode 100644 PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.inc
 create mode 100644 PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.php

diff --git a/PHPCompatibility/Sniffs/Numbers/NewNumericLiteralSeparatorSniff.php b/PHPCompatibility/Sniffs/Numbers/NewNumericLiteralSeparatorSniff.php
new file mode 100644
index 000000000..a5fe92461
--- /dev/null
+++ b/PHPCompatibility/Sniffs/Numbers/NewNumericLiteralSeparatorSniff.php
@@ -0,0 +1,86 @@
+<?php
+/**
+ * PHPCompatibility, an external standard for PHP_CodeSniffer.
+ *
+ * @package   PHPCompatibility
+ * @copyright 2012-2020 PHPCompatibility Contributors
+ * @license   https://opensource.org/licenses/LGPL-3.0 LGPL3
+ * @link      https://github.com/PHPCompatibility/PHPCompatibility
+ */
+
+namespace PHPCompatibility\Sniffs\Numbers;
+
+use PHP_CodeSniffer_File as File;
+use PHP_CodeSniffer\Exceptions\RuntimeException;
+use PHPCompatibility\Sniff;
+use PHPCSUtils\Utils\Numbers;
+
+/**
+ * Support for an underscore in numeric literals to visually separate groups of digits
+ * is available since PHP 7.4.
+ *
+ * PHP version 7.4
+ *
+ * @link https://www.php.net/manual/en/migration74.new-features.php#migration74.new-features.core.numeric-literal-separator
+ * @link https://wiki.php.net/rfc/numeric_literal_separator
+ *
+ * @since 10.0.0
+ */
+class NewNumericLiteralSeparatorSniff extends Sniff
+{
+
+    /**
+     * Returns an array of tokens this test wants to listen for.
+     *
+     * @since 10.0.0
+     *
+     * @return array
+     */
+    public function register()
+    {
+        return array(
+            \T_LNUMBER,
+            \T_DNUMBER,
+        );
+    }
+
+    /**
+     * Processes this test, when one of its tokens is encountered.
+     *
+     * @since 10.0.0
+     *
+     * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned.
+     * @param int                   $stackPtr  The position of the current token in the
+     *                                         stack passed in $tokens.
+     *
+     * @return int|void Integer stack pointer to skip forward or void to continue
+     *                  normal file processing.
+     */
+    public function process(File $phpcsFile, $stackPtr)
+    {
+        if ($this->supportsBelow('7.3') === false) {
+            return;
+        }
+
+        try {
+            $numberInfo = Numbers::getCompleteNumber($phpcsFile, $stackPtr);
+            if ($numberInfo['orig_content'] === $numberInfo['content']) {
+                // Content is the same, i.e. no underscores found, move on.
+                return;
+            }
+
+            $phpcsFile->addError(
+                'The use of underscore separators in numeric literals is not supported in PHP 7.3 or lower. Found: %s',
+                $stackPtr,
+                'Found',
+                array($numberInfo['orig_content'])
+            );
+
+            // Skip past the parts we've already taken into account to prevent double reporting.
+            return ($numberInfo['last_token'] + 1);
+        } catch (RuntimeException $e) {
+            // Running on an unsupport PHPCS version.
+            return;
+        }
+    }
+}
diff --git a/PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.inc b/PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.inc
new file mode 100644
index 000000000..d4f4068d1
--- /dev/null
+++ b/PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.inc
@@ -0,0 +1,41 @@
+<?php
+
+// OK: ordinary numeric sequences.
+$a = 1000000000;
+$b = 107925284.88;
+$discount = 13500;
+
+// OK: Constant name starting with an underscore is perfectly valid.
+const _100 = 100;
+
+$a = 100 'test'; // Intentional parse error, not our concern.
+
+// PHP 7.4 numeric sequences with a numeric literal separator.
+$threshold = 1_000_000_000;  // a billion!
+$testValue = 107_925_284.88; // scale is hundreds of millions
+$discount  = 135_00;         // $135, stored as cents
+
+$a = 6.674_083e-11; // float
+$a = 6.674_083e+11; // float
+$a = 299_792_458;   // decimal
+$a = 0xCAFE_F00D;   // hexadecimal
+$a = 0b0101_1111;   // binary
+$a = 0137_041;      // octal
+
+// More test cases.
+$a = 1_2.3_4e1_23;
+
+// Invalid use of underscores in numeric sequences.
+// Each underscore in a numeric literal must be directly between two digits.
+// These below all produce "Parse error: syntax error" in PHP 7.4.
+$a = 100_;   // trailing
+$a = 1__1;   // next to underscore
+$a = 1_.0;   // next to decimal point
+$a = 1._0;   // next to decimal point
+$a = 0x_123; // next to x
+$a = 0b_101; // next to b
+$a = 1_e2;   // next to e
+$a = 1e_2;   // next to e
+
+// More test cases.
+$a = 0xCAFE_F00D_.892;
diff --git a/PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.php b/PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.php
new file mode 100644
index 000000000..f5bc0808c
--- /dev/null
+++ b/PHPCompatibility/Tests/Numbers/NewNumericLiteralSeparatorUnitTest.php
@@ -0,0 +1,141 @@
+<?php
+/**
+ * PHPCompatibility, an external standard for PHP_CodeSniffer.
+ *
+ * @package   PHPCompatibility
+ * @copyright 2012-2020 PHPCompatibility Contributors
+ * @license   https://opensource.org/licenses/LGPL-3.0 LGPL3
+ * @link      https://github.com/PHPCompatibility/PHPCompatibility
+ */
+
+namespace PHPCompatibility\Tests\Numbers;
+
+use PHPCompatibility\Tests\BaseSniffTest;
+use PHPCSUtils\BackCompat\Helper;
+
+/**
+ * New Numeric Literal Separator Sniff tests
+ *
+ * @group newNumericLiteralSeparator
+ * @group numbers
+ *
+ * @covers \PHPCompatibility\Sniffs\Numbers\NewNumericLiteralSeparatorSniff
+ *
+ * @since 10.0.0
+ */
+class NewNumericLiteralSeparatorUnitTest extends BaseSniffTest
+{
+
+    /**
+     * Test recognizing numeric literals with underscores correctly.
+     *
+     * @dataProvider dataNewNumericLiteralSeparator
+     *
+     * @param array $line The line number on which the error should occur.
+     *
+     * @return void
+     */
+    public function testNewNumericLiteralSeparator($line)
+    {
+        if (version_compare(Helper::getVersion(), '3.5.3', '==')) {
+            $this->markTestSkipped('PHPCS 3.5.3 is not supported for this sniff');
+        }
+
+        $file = $this->sniffFile(__FILE__, '7.3');
+        $this->assertError($file, $line, 'The use of underscore separators in numeric literals is not supported in PHP 7.3 or lower. Found:');
+    }
+
+    /**
+     * Data provider.
+     *
+     * @see testNewNumericLiteralSeparator()
+     *
+     * @return array
+     */
+    public function dataNewNumericLiteralSeparator()
+    {
+        $data = array(
+            array(14),
+            array(15),
+            array(16),
+            array(18),
+            array(19),
+            array(20),
+            array(21),
+            array(22),
+            array(23),
+            array(26),
+        );
+
+        // The test case on line 39 is half a valid numeric literal with underscore, half parse error.
+        // The sniff will behave differently on PHP 7.4 vs PHP < 7.4.
+        if (version_compare(\PHP_VERSION_ID, '70399', '>') || version_compare(Helper::getVersion(), '3.5.3', '<')) {
+            $data[] = array(41);
+        }
+
+        return $data;
+    }
+
+
+    /**
+     * Verify there are no false positives for a PHP version on which this sniff throws errors.
+     *
+     * @dataProvider dataNoFalsePositives
+     *
+     * @param int $line The line number.
+     *
+     * @return void
+     */
+    public function testNoFalsePositives($line)
+    {
+        $file = $this->sniffFile(__FILE__, '7.3');
+        $this->assertNoViolation($file, $line);
+    }
+
+    /**
+     * Data provider.
+     *
+     * @see testNoFalsePositives()
+     *
+     * @return array
+     */
+    public function dataNoFalsePositives()
+    {
+        $data = array();
+
+        // No issues expected on the first 12 lines.
+        for ($i = 1; $i <= 12; $i++) {
+            $data[] = array($i);
+        }
+
+        // Parse errors, should be ignored by the sniff.
+        $data[] = array(31);
+        $data[] = array(32);
+        $data[] = array(33);
+        $data[] = array(34);
+        $data[] = array(35);
+        $data[] = array(36);
+        $data[] = array(37);
+        $data[] = array(38);
+
+        // The test case on line 39 is half a valid numeric literal with underscore, half parse error.
+        // The sniff will behave differently on PHP 7.4 vs PHP < 7.4.
+        if (version_compare(\PHP_VERSION_ID, '70399', '<=') && version_compare(Helper::getVersion(), '3.5.3', '>')) {
+            $data[] = array(41);
+        }
+
+        return $data;
+    }
+
+
+    /**
+     * Verify no notices are thrown at all.
+     *
+     * @return void
+     */
+    public function testNoViolationsInFileOnValidVersion()
+    {
+        $file = $this->sniffFile(__FILE__, '7.4');
+        $this->assertNoViolation($file);
+    }
+}