Add SpreadAssignment Mutator

resources/schema.json

@@ -324,6 +324,7 @@
                 "This": { "$ref": "#/definitions/default-mutator-config" },
                 "Spaceship": { "$ref": "#/definitions/default-mutator-config" },
                 "Spread": { "$ref": "#/definitions/default-mutator-config" },
+                "SpreadAssignment": { "$ref": "#/definitions/default-mutator-config" },
                 "SpreadRemoval": { "$ref": "#/definitions/default-mutator-config" },
                 "Foreach_": { "$ref": "#/definitions/default-mutator-config" },
                 "For_": { "$ref": "#/definitions/default-mutator-config" },

src/Mutator/Operator/SpreadAssignment.php

@@ -0,0 +1,107 @@
+<?php
+/**
+ * This code is licensed under the BSD 3-Clause License.
+ *
+ * Copyright (c) 2017, Maks Rafalko
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the copyright holder nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Mutator\Operator;
+
+use function count;
+use Infection\Mutator\Definition;
+use Infection\Mutator\GetMutatorName;
+use Infection\Mutator\Mutator;
+use Infection\Mutator\MutatorCategory;
+use PhpParser\Node;
+use Webmozart\Assert\Assert;
+
+/**
+ * @internal
+ *
+ * @implements Mutator<Node\Expr\Array_>
+ */
+final class SpreadAssignment implements Mutator
+{
+    use GetMutatorName;
+
+    public static function getDefinition(): ?Definition
+    {
+        return new Definition(
+            <<<'TXT'
+Removes a spread operator in an array expression and turns it into an assignment. For example:
+
+```php
+$x = [...$collection];
+```
+
+Will be mutated to:
+
+```php
+$x = $collection;
+```
+TXT
+            ,
+            MutatorCategory::SEMANTIC_REDUCTION,
+            null,
+            <<<'DIFF'
+- $x = [...$collection];
++ $x = $collection;
+DIFF
+        );
+    }
+
+    /**
+     * @psalm-mutation-free
+     *
+     * @return iterable<Node\Expr>
+     */
+    public function mutate(Node $node): iterable
+    {
+        Assert::allNotNull($node->items);
+
+        yield $node->items[0]->value;
+    }
+
+    public function canMutate(Node $node): bool
+    {
+        if (!$node instanceof Node\Expr\Array_) {
+            return false;
+        }
+
+        if (count($node->items) !== 1) {
+            return false;
+        }
+
+        Assert::allNotNull($node->items);
+
+        return $node->items[0]->unpack;
+    }
+}

src/Mutator/ProfileList.php

@@ -159,6 +159,7 @@ final class ProfileList
         Mutator\Operator\NullSafeMethodCall::class,
         Mutator\Operator\NullSafePropertyCall::class,
         Mutator\Operator\Spread::class,
+        Mutator\Operator\SpreadAssignment::class,
         Mutator\Operator\SpreadRemoval::class,
         Mutator\Operator\Ternary::class,
         Mutator\Operator\Throw_::class,
@@ -363,6 +364,7 @@ final class ProfileList
         'NullSafeMethodCall' => Mutator\Operator\NullSafeMethodCall::class,
         'NullSafePropertyCall' => Mutator\Operator\NullSafePropertyCall::class,
         'Spread' => Mutator\Operator\Spread::class,
+        'SpreadAssignment' => Mutator\Operator\SpreadAssignment::class,
         'SpreadRemoval' => Mutator\Operator\SpreadRemoval::class,
         'Ternary' => Mutator\Operator\Ternary::class,
         'Throw_' => Mutator\Operator\Throw_::class,

tests/phpunit/Mutator/Operator/SpreadAssignmentTest.php

@@ -0,0 +1,172 @@
+<?php
+/**
+ * This code is licensed under the BSD 3-Clause License.
+ *
+ * Copyright (c) 2017, Maks Rafalko
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the copyright holder nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Tests\Mutator\Operator;
+
+use Infection\Tests\Mutator\BaseMutatorTestCase;
+
+final class SpreadAssignmentTest extends BaseMutatorTestCase
+{
+    /**
+     * @requires PHP >= 7.4
+     * @dataProvider mutationsProvider
+     *
+     * @param string|string[] $expected
+     */
+    public function test_it_can_mutate(string $input, $expected = []): void
+    {
+        $this->doTest($input, $expected);
+    }
+
+    public function mutationsProvider(): iterable
+    {
+        yield 'Spread assignment for a raw array' => [
+            <<<'PHP'
+<?php
+
+$a = [...[1, 2, 3]];
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$a = [1, 2, 3];
+PHP
+            ,
+        ];
+
+        yield 'Spread assignment for a raw empty array' => [
+            <<<'PHP'
+<?php
+
+$a = [...[]];
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$a = [];
+PHP
+            ,
+        ];
+
+        yield 'Spread assignment for a variable' => [
+            <<<'PHP'
+<?php
+
+$a = [...$collection];
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$a = $collection;
+PHP
+            ,
+        ];
+
+        yield 'Spread assignment for a function call' => [
+            <<<'PHP'
+<?php
+
+$a = [...getCollection()];
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$a = getCollection();
+PHP
+            ,
+        ];
+
+        yield 'Spread assignment for a method call' => [
+            <<<'PHP'
+<?php
+
+$a = [...$object->getCollection()];
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$a = $object->getCollection();
+PHP
+            ,
+        ];
+
+        yield 'Spread assignment for a new iterator object' => [
+            <<<'PHP'
+<?php
+
+$a = [...new ArrayIterator(['a', 'b', 'c'])];
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$a = new ArrayIterator(['a', 'b', 'c']);
+PHP
+            ,
+        ];
+
+        yield 'It does not mutate argument unpacking' => [
+            <<<'PHP'
+<?php
+
+function foo(...$array) {}
+PHP
+            ,
+        ];
+
+        yield 'It does not mutate list construct' => [
+            <<<'PHP'
+<?php
+
+[$left, $right] = ['left', 'right'];
+PHP
+            ,
+        ];
+
+        yield 'It does not mutate spread expression in array with more than one element' => [
+            <<<'PHP'
+<?php
+
+$a = [...[1, 2, 3], 4];
+PHP
+            ,
+        ];
+    }
+}