From b767c632be7d446a115030f358f868e4121fb40b Mon Sep 17 00:00:00 2001
From: jrfnl <jrfnl@users.noreply.github.com>
Date: Wed, 28 Mar 2018 06:27:17 +0200
Subject: [PATCH] :sparkles: PHP 7.3: New sniff to detect references in list
 constructs

> Array destructuring now supports reference assignments using the syntax `[&$a, [$b, &$c]] = $d`. The same is also supported for `list()`.

Refs:
* https://wiki.php.net/rfc/list_reference_assignment
* https://github.com/php/php-src/commit/6d4de4cf0582cf33848826ab78aae58077dc2dea
* https://github.com/php/php-src/blob/9b89b09b24ffe29c2b6de24c3d9b21df4f2a9de0/UPGRADING#L58-L60
---
 .../Lists/NewListReferenceAssignmentSniff.php |  66 ++++++++++
 .../NewListReferenceAssignmentUnitTest.inc    |  37 ++++++
 .../NewListReferenceAssignmentUnitTest.php    | 117 ++++++++++++++++++
 3 files changed, 220 insertions(+)
 create mode 100644 PHPCompatibility/Sniffs/Lists/NewListReferenceAssignmentSniff.php
 create mode 100644 PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.inc
 create mode 100644 PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.php

diff --git a/PHPCompatibility/Sniffs/Lists/NewListReferenceAssignmentSniff.php b/PHPCompatibility/Sniffs/Lists/NewListReferenceAssignmentSniff.php
new file mode 100644
index 000000000..825ea98e9
--- /dev/null
+++ b/PHPCompatibility/Sniffs/Lists/NewListReferenceAssignmentSniff.php
@@ -0,0 +1,66 @@
+<?php
+/**
+ * \PHPCompatibility\Sniffs\Lists\NewListReferenceAssignmentSniff.
+ *
+ * PHP version 7.3
+ *
+ * @category PHP
+ * @package  PHPCompatibility
+ * @author   Juliette Reinders Folmer <phpcompatibility_nospam@adviesenzo.nl>
+ */
+
+namespace PHPCompatibility\Sniffs\Lists;
+
+use PHPCompatibility\Sniffs\Lists\NewKeyedListSniff;
+
+/**
+ * Detect reference assignments in array destructuring using (short) list.
+ *
+ * PHP version 7.3
+ *
+ * @category PHP
+ * @package  PHPCompatibility
+ * @author   Juliette Reinders Folmer <phpcompatibility_nospam@adviesenzo.nl>
+ */
+class NewListReferenceAssignmentSniff extends NewKeyedListSniff
+{
+    /**
+     * The token(s) within the list construct which is being targeted.
+     *
+     * @var array
+     */
+    protected $targetsInList = array(
+        T_BITWISE_AND => T_BITWISE_AND,
+    );
+
+    /**
+     * Do a version check to determine if this sniff needs to run at all.
+     *
+     * @return bool
+     */
+    protected function bowOutEarly()
+    {
+        return ($this->supportsBelow('7.2') === false);
+    }
+
+    /**
+     * Examine the contents of a list construct to determine whether an error needs to be thrown.
+     *
+     * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned.
+     * @param int                   $opener    The position of the list open token.
+     * @param int                   $closer    The position of the list close token.
+     *
+     * @return void
+     */
+    protected function examineList(\PHP_CodeSniffer_File $phpcsFile, $opener, $closer)
+    {
+        $start   = $opener;
+        while (($start = $this->hasTargetInList($phpcsFile, $start, $closer)) !== false) {
+            $phpcsFile->addError(
+                'Reference assignments within list constructs are not supported in PHP 7.2 or earlier.',
+                $start,
+                'Found'
+            );
+        }
+    }
+}
diff --git a/PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.inc b/PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.inc
new file mode 100644
index 000000000..4f7b53f67
--- /dev/null
+++ b/PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.inc
@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * Valid prior to PHP 7.3.
+ */
+list($id1, $name1) = $data[0];
+[$id1, $name1] = $data[0];
+
+foreach ($data as list($id, $name)) {}
+foreach ($data as [$id, $name]) {}
+
+
+/*
+ * PHP 7.3: list() reference assignments.
+ */
+list($a, &$b) = $array;
+[$a, &$b] = $array;
+
+list(
+    &$a,
+    $b,
+    ,
+    list(
+        &$c,
+        $d
+    )
+) = $array;
+
+[
+    &$a,
+    $b,
+    ,
+    [&$c, &$d]
+] = $array;
+
+foreach ($array as list(&$a, &$b)) {}
+foreach ($array as [&$a, $b]) {}
diff --git a/PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.php b/PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.php
new file mode 100644
index 000000000..c95bf56e8
--- /dev/null
+++ b/PHPCompatibility/Tests/Sniffs/Lists/NewListReferenceAssignmentUnitTest.php
@@ -0,0 +1,117 @@
+<?php
+/**
+ * PHP 7.3 list reference assignments sniff test file.
+ *
+ * @package PHPCompatibility
+ */
+
+namespace PHPCompatibility\Tests\Sniffs\Lists;
+
+use PHPCompatibility\Tests\BaseSniffTest;
+
+/**
+ * PHP 7.3 list reference assignments sniff test file.
+ *
+ * @group newListReferenceAssignment
+ * @group lists
+ *
+ * @covers \PHPCompatibility\Sniffs\Lists\NewListReferenceAssignmentSniff
+ *
+ * @uses    \PHPCompatibility\Tests\BaseSniffTest
+ * @package PHPCompatibility
+ * @author  Juliette Reinders Folmer <phpcompatibility_nospam@adviesenzo.nl>
+ */
+class NewListReferenceAssignmentUnitTest extends BaseSniffTest
+{
+    const TEST_FILE = 'Sniffs/Lists/NewListReferenceAssignmentUnitTest.inc';
+
+    /**
+     * testNewListReferenceAssignment
+     *
+     * @dataProvider dataNewListReferenceAssignment
+     *
+     * @param int $line Line number where the error should occur.
+     *
+     * @return void
+     */
+    public function testNewListReferenceAssignment($line)
+    {
+        $file = $this->sniffFile(self::TEST_FILE, '7.2');
+        $this->assertError($file, $line, 'Reference assignments within list constructs are not supported in PHP 7.2 or earlier.');
+    }
+
+    /**
+     * dataNewListReferenceAssignment
+     *
+     * @see testNewListReferenceAssignment()
+     *
+     * @return array
+     */
+    public function dataNewListReferenceAssignment()
+    {
+        return array(
+            array(16),
+            array(17),
+            array(20),
+            array(24),
+            array(30),
+            array(33), // x2.
+            array(36), // x2.
+            array(37),
+        );
+    }
+
+
+    /**
+     * testNoFalsePositives
+     *
+     * @dataProvider dataNoFalsePositives
+     *
+     * @param int $line Line number with a valid list assignment.
+     *
+     * @return void
+     */
+    public function testNoFalsePositives($line)
+    {
+        $file = $this->sniffFile(self::TEST_FILE, '7.2');
+        $this->assertNoViolation($file, $line);
+    }
+
+    /**
+     * dataNoFalsePositives
+     *
+     * @see testNoFalsePositives()
+     *
+     * @return array
+     */
+    public function dataNoFalsePositives()
+    {
+        return array(
+            array(6),
+            array(7),
+            array(9),
+            array(10),
+            array(19),
+            array(21),
+            array(22),
+            array(23),
+            array(25),
+            array(29),
+            array(31),
+            array(32),
+        );
+    }
+
+
+    /**
+     * Verify no notices are thrown at all.
+     *
+     * @return void
+     */
+    public function testNoViolationsInFileOnValidVersion()
+    {
+        $file = $this->sniffFile(self::TEST_FILE, '7.3');
+        $this->assertNoViolation($file);
+    }
+
+}