Downgrade php74 array spread

rules/downgrade-php74/src/Rector/Array_/DowngradeArraySpreadRector.php

@@ -0,0 +1,201 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DowngradePhp74\Rector\Array_;
+
+use PhpParser\Node;
+use PhpParser\Node\Arg;
+use PhpParser\Node\Expr\Array_;
+use PhpParser\Node\Expr\ArrayItem;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\Ternary;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Name;
+use PHPStan\Analyser\Scope;
+use Rector\Core\Rector\AbstractRector;
+use Rector\Core\RectorDefinition\CodeSample;
+use Rector\Core\RectorDefinition\RectorDefinition;
+use Rector\NetteKdyby\Naming\VariableNaming;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+
+/**
+ * @see \Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\DowngradeArraySpreadRectorTest
+ */
+final class DowngradeArraySpreadRector extends AbstractRector
+{
+    /**
+     * @var VariableNaming
+     */
+    private $variableNaming;
+
+    public function __construct(VariableNaming $variableNaming)
+    {
+        $this->variableNaming = $variableNaming;
+    }
+
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Replace array spread with array_merge function', [
+            new CodeSample(
+                <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run()
+    {
+        $parts = ['apple', 'pear'];
+        $fruits = ['banana', 'orange', ...$parts, 'watermelon'];
+    }
+
+    public function runWithIterable()
+    {
+        $fruits = ['banana', 'orange', ...new ArrayIterator(['durian', 'kiwi']), 'watermelon'];
+    }
+}
+CODE_SAMPLE
+                ,
+                <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run()
+    {
+        $parts = ['apple', 'pear'];
+        $fruits = array_merge(['banana', 'orange'], $parts, ['watermelon']);
+    }
+
+    public function runWithIterable()
+    {
+        $item0Unpacked = new ArrayIterator(['durian', 'kiwi']);
+        $fruits = array_merge(['banana', 'orange'], is_array($item0Unpacked) ? $item0Unpacked : iterator_to_array($item0Unpacked), ['watermelon']);
+    }
+}
+CODE_SAMPLE
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [Array_::class];
+    }
+
+    /**
+     * @param Array_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if (! $this->shouldRefactor($node)) {
+            return null;
+        }
+        return $this->refactorNode($node);
+    }
+
+    private function shouldRefactor(Array_ $array): bool
+    {
+        // Check that any item in the array is the spread
+        return count(array_filter($array->items, function (?ArrayItem $item): bool {
+            return $item !== null && $item->unpack;
+        })) > 0;
+    }
+
+    /**
+     * Iterate all array items:
+     * 1. If they use the spread, remove it
+     * 2. If not, make the item part of an accumulating array,
+     *    to be added once the next spread is found, or at the end
+     */
+    private function refactorNode(Array_ $array): Node
+    {
+        $newItems = [];
+        $accumulatedItems = [];
+        foreach ($array->items as $position => $item) {
+            if ($item !== null && $item->unpack) {
+                // Spread operator found
+                // If it is a not variable, transform it to a variable
+                if (! $item->value instanceof Variable) {
+                    $item->value = $this->createVariableFromNonVariable($array, $item, $position);
+                }
+                if ($accumulatedItems !== []) {
+                    // If previous items were in the new array, add them first
+                    $newItems[] = $this->createArrayItem($accumulatedItems);
+                    // Reset the accumulated items
+                    $accumulatedItems = [];
+                }
+                // Add the current item, still with "unpack = true" (it will be removed later on)
+                $newItems[] = $item;
+                continue;
+            }
+
+            // Normal item, it goes into the accumulated array
+            $accumulatedItems[] = $item;
+        }
+        // Add the remaining accumulated items
+        if ($accumulatedItems !== []) {
+            $newItems[] = $this->createArrayItem($accumulatedItems);
+        }
+        // Replace this array node with an `array_merge`
+        return $this->createArrayMerge($newItems);
+    }
+
+    /**
+     * If it is a variable, we add it directly
+     * Otherwise it could be a function, method, ternary, traversable, etc
+     * We must then first extract it into a variable,
+     * as to invoke it only once and avoid potential bugs,
+     * such as a method executing some side-effect
+     * @param int|string $position
+     */
+    private function createVariableFromNonVariable(Array_ $array, ArrayItem $arrayItem, $position): Variable
+    {
+        /** @var Scope */
+        $nodeScope = $array->getAttribute(AttributeKey::SCOPE);
+        // The variable name will be item0Unpacked, item1Unpacked, etc,
+        // depending on their position.
+        // The number can't be at the end of the var name, or it would
+        // conflict with the counter (for if that name is already taken)
+        $variableName = $this->variableNaming->resolveFromNodeWithScopeCountAndFallbackName(
+            $array,
+            $nodeScope,
+            'item' . $position . 'Unpacked'
+        );
+        // Assign the value to the variable, and replace the element with the variable
+        $newVariable = new Variable($variableName);
+        $this->addNodeBeforeNode(new Assign($newVariable, $arrayItem->value), $array);
+        return $newVariable;
+    }
+
+    /**
+     * @param (ArrayItem|null)[] $items
+     */
+    private function createArrayItem(array $items): ArrayItem
+    {
+        return new ArrayItem(new Array_($items));
+    }
+
+    /**
+     * @see https://wiki.php.net/rfc/spread_operator_for_array
+     * @param (ArrayItem|null)[] $items
+     */
+    private function createArrayMerge(array $items): FuncCall
+    {
+        return new FuncCall(new Name('array_merge'), array_map(function (ArrayItem $item): Arg {
+            if ($item !== null && $item->unpack) {
+                // Do not unpack anymore
+                $item->unpack = false;
+                // array_merge only supports array, while spread operator also supports objects implementing Traversable.
+                return new Arg(
+                    new Ternary(
+                        new FuncCall(new Name('is_array'), [new Arg($item)]),
+                        $item,
+                        new FuncCall(new Name('iterator_to_array'), [new Arg($item)])
+                    )
+                );
+            }
+            return new Arg($item);
+        }, $items));
+    }
+}

rules/downgrade-php74/tests/Rector/Array_/DowngradeArraySpreadRector/DowngradeArraySpreadRectorTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector;
+
+use Iterator;
+use Rector\Core\Testing\PHPUnit\AbstractRectorTestCase;
+use Rector\Core\ValueObject\PhpVersionFeature;
+use Rector\DowngradePhp74\Rector\Array_\DowngradeArraySpreadRector;
+use Symplify\SmartFileSystem\SmartFileInfo;
+
+final class DowngradeArraySpreadRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @requires PHP 7.4
+     * @dataProvider provideData()
+     */
+    public function test(SmartFileInfo $fileInfo): void
+    {
+        $this->doTestFileInfo($fileInfo);
+    }
+
+    public function provideData(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    protected function getRectorClass(): string
+    {
+        return DowngradeArraySpreadRector::class;
+    }
+
+    protected function getPhpVersion(): string
+    {
+        return PhpVersionFeature::BEFORE_ARRAY_SPREAD;
+    }
+}

rules/downgrade-php74/tests/Rector/Array_/DowngradeArraySpreadRector/Fixture/array_fn_name.php.inc

@@ -0,0 +1,29 @@
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+class ArrayFunctionNameClass
+{
+    public function run()
+    {
+        $parts = array('apple', 'pear');
+        $fruits = array('banana', 'orange', ...$parts, 'watermelon');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+class ArrayFunctionNameClass
+{
+    public function run()
+    {
+        $parts = array('apple', 'pear');
+        $fruits = array_merge(['banana', 'orange'], is_array($parts) ? $parts : iterator_to_array($parts), ['watermelon']);
+    }
+}
+
+?>

rules/downgrade-php74/tests/Rector/Array_/DowngradeArraySpreadRector/Fixture/combined_items.php.inc

@@ -0,0 +1,34 @@
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+use ArrayIterator;
+
+class CombinedItemsClass
+{
+    public function run()
+    {
+        $parts = ['apple', 'pear'];
+        $fruits = ['banana', 'orange', ...$parts, 'watermelon', ...new ArrayIterator(['durian', 'kiwi'])];
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+use ArrayIterator;
+
+class CombinedItemsClass
+{
+    public function run()
+    {
+        $parts = ['apple', 'pear'];
+        $item4Unpacked = new ArrayIterator(['durian', 'kiwi']);
+        $fruits = array_merge(['banana', 'orange'], is_array($parts) ? $parts : iterator_to_array($parts), ['watermelon'], is_array($item4Unpacked) ? $item4Unpacked : iterator_to_array($item4Unpacked));
+    }
+}
+
+?>

rules/downgrade-php74/tests/Rector/Array_/DowngradeArraySpreadRector/Fixture/different_positions.php.inc

@@ -0,0 +1,45 @@
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+class DifferentPositionsClass
+{
+    public function run()
+    {
+        $parts1 = ['apple', 'pear'];
+        $parts2 = ['orange'];
+        $parts3 = ['banana', 'kiwi', 'pomelo'];
+        $fruits = [...$parts1, ...$parts2, ...$parts3];
+        $fruits = ['durian', ...$parts1, ...$parts2, ...$parts3];
+        $fruits = [...$parts1, ...$parts2, ...$parts3, 'durian'];
+        $fruits = ['rambutan', 'longan', ...$parts1, ...$parts2, ...$parts3, 'durian'];
+        $fruits = ['rambutan', 'longan', ...$parts1, ...$parts2, ...$parts3, 'durian'];
+        $fruits = ['rambutan', 'longan', ...$parts1, ...$parts2, 'watermelon', ...$parts3, 'durian'];
+        $fruits = ['rambutan', 'longan', ...$parts1, ...$parts2, 'watermelon', ...$parts3];
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+class DifferentPositionsClass
+{
+    public function run()
+    {
+        $parts1 = ['apple', 'pear'];
+        $parts2 = ['orange'];
+        $parts3 = ['banana', 'kiwi', 'pomelo'];
+        $fruits = array_merge(is_array($parts1) ? $parts1 : iterator_to_array($parts1), is_array($parts2) ? $parts2 : iterator_to_array($parts2), is_array($parts3) ? $parts3 : iterator_to_array($parts3));
+        $fruits = array_merge(['durian'], is_array($parts1) ? $parts1 : iterator_to_array($parts1), is_array($parts2) ? $parts2 : iterator_to_array($parts2), is_array($parts3) ? $parts3 : iterator_to_array($parts3));
+        $fruits = array_merge(is_array($parts1) ? $parts1 : iterator_to_array($parts1), is_array($parts2) ? $parts2 : iterator_to_array($parts2), is_array($parts3) ? $parts3 : iterator_to_array($parts3), ['durian']);
+        $fruits = array_merge(['rambutan', 'longan'], is_array($parts1) ? $parts1 : iterator_to_array($parts1), is_array($parts2) ? $parts2 : iterator_to_array($parts2), is_array($parts3) ? $parts3 : iterator_to_array($parts3), ['durian']);
+        $fruits = array_merge(['rambutan', 'longan'], is_array($parts1) ? $parts1 : iterator_to_array($parts1), is_array($parts2) ? $parts2 : iterator_to_array($parts2), is_array($parts3) ? $parts3 : iterator_to_array($parts3), ['durian']);
+        $fruits = array_merge(['rambutan', 'longan'], is_array($parts1) ? $parts1 : iterator_to_array($parts1), is_array($parts2) ? $parts2 : iterator_to_array($parts2), ['watermelon'], is_array($parts3) ? $parts3 : iterator_to_array($parts3), ['durian']);
+        $fruits = array_merge(['rambutan', 'longan'], is_array($parts1) ? $parts1 : iterator_to_array($parts1), is_array($parts2) ? $parts2 : iterator_to_array($parts2), ['watermelon'], is_array($parts3) ? $parts3 : iterator_to_array($parts3));
+    }
+}
+
+?>

rules/downgrade-php74/tests/Rector/Array_/DowngradeArraySpreadRector/Fixture/fixture.php.inc

@@ -0,0 +1,29 @@
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+class FixtureClass
+{
+    public function run()
+    {
+        $parts = ['apple', 'pear'];
+        $fruits = ['banana', 'orange', ...$parts, 'watermelon'];
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DowngradePhp74\Tests\Rector\Array_\DowngradeArraySpreadRector\Fixture;
+
+class FixtureClass
+{
+    public function run()
+    {
+        $parts = ['apple', 'pear'];
+        $fruits = array_merge(['banana', 'orange'], is_array($parts) ? $parts : iterator_to_array($parts), ['watermelon']);
+    }
+}
+
+?>