Add PHP 8 specific NullSafe operator mutators (#1457)

* Add NullSafe operator mutators

* fix The lock file is not up to date with the latest changes in composer.json

* apply code style

* fix the order of new mutators in the ProfileList

* fix the order of new mutators in the ProfileList

* Add more tests

devTools/Dockerfile-php80-xdebug

@@ -1,6 +1,6 @@
 FROM php:8.0-cli-alpine
 
-ARG XDEBUG_VERSION=3.0.0
+ARG XDEBUG_VERSION=3.0.1
 
 RUN set -eux; \
     apk add --no-cache --virtual .build-deps \

resources/schema.json

@@ -256,6 +256,8 @@
                 "Concat": { "$ref": "#/definitions/default-mutator-config" },
                 "PregQuote": { "$ref": "#/definitions/default-mutator-config" },
                 "PregMatchMatches": { "$ref": "#/definitions/default-mutator-config" },
+                "NullSafePropertyCall": { "$ref": "#/definitions/default-mutator-config" },
+                "NullSafeMethodCall": { "$ref": "#/definitions/default-mutator-config" },
                 "ArrayItemRemoval": {
                     "anyOf": [
                         {

src/Mutator/Operator/NullSafeMethodCall.php

@@ -0,0 +1,81 @@
+<?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 Infection\Mutator\Definition;
+use Infection\Mutator\GetMutatorName;
+use Infection\Mutator\Mutator;
+use Infection\Mutator\MutatorCategory;
+use const PHP_VERSION_ID;
+use PhpParser\Node;
+
+/**
+ * @internal
+ *
+ * @implements Mutator<Node\Expr\NullsafeMethodCall>
+ */
+final class NullSafeMethodCall implements Mutator
+{
+    use GetMutatorName;
+
+    public static function getDefinition(): ?Definition
+    {
+        return new Definition(
+            <<<'TXT'
+Replaces the nullsafe method call operator (`?->`) with (`->`).
+TXT
+            ,
+            MutatorCategory::SEMANTIC_REDUCTION,
+            null
+        );
+    }
+
+    /**
+     * @psalm-mutation-free
+     *
+     * @return iterable<Node\Expr\MethodCall>
+     */
+    public function mutate(Node $node): iterable
+    {
+        yield new Node\Expr\MethodCall($node->var, $node->name, $node->args, $node->getAttributes());
+    }
+
+    public function canMutate(Node $node): bool
+    {
+        return PHP_VERSION_ID >= 80000
+            && $node instanceof Node\Expr\NullsafeMethodCall;
+    }
+}

src/Mutator/Operator/NullSafePropertyCall.php

@@ -0,0 +1,81 @@
+<?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 Infection\Mutator\Definition;
+use Infection\Mutator\GetMutatorName;
+use Infection\Mutator\Mutator;
+use Infection\Mutator\MutatorCategory;
+use const PHP_VERSION_ID;
+use PhpParser\Node;
+
+/**
+ * @internal
+ *
+ * @implements Mutator<Node\Expr\NullsafePropertyFetch>
+ */
+final class NullSafePropertyCall implements Mutator
+{
+    use GetMutatorName;
+
+    public static function getDefinition(): ?Definition
+    {
+        return new Definition(
+            <<<'TXT'
+Replaces the nullsafe property call operator (`?->`) with (`->`).
+TXT
+            ,
+            MutatorCategory::SEMANTIC_REDUCTION,
+            null
+        );
+    }
+
+    /**
+     * @psalm-mutation-free
+     *
+     * @return iterable<Node\Expr\PropertyFetch>
+     */
+    public function mutate(Node $node): iterable
+    {
+        yield new Node\Expr\PropertyFetch($node->var, $node->name, $node->getAttributes());
+    }
+
+    public function canMutate(Node $node): bool
+    {
+        return PHP_VERSION_ID >= 80000
+            && $node instanceof Node\Expr\NullsafePropertyFetch;
+    }
+}

src/Mutator/ProfileList.php

@@ -156,6 +156,8 @@ final class ProfileList
         Mutator\Operator\Concat::class,
         Mutator\Operator\Continue_::class,
         Mutator\Operator\Finally_::class,
+        Mutator\Operator\NullSafeMethodCall::class,
+        Mutator\Operator\NullSafePropertyCall::class,
         Mutator\Operator\Spread::class,
         Mutator\Operator\Ternary::class,
         Mutator\Operator\Throw_::class,
@@ -354,6 +356,8 @@ final class ProfileList
         'Concat' => Mutator\Operator\Concat::class,
         'Continue_' => Mutator\Operator\Continue_::class,
         'Finally_' => Mutator\Operator\Finally_::class,
+        'NullSafeMethodCall' => Mutator\Operator\NullSafeMethodCall::class,
+        'NullSafePropertyCall' => Mutator\Operator\NullSafePropertyCall::class,
         'Spread' => Mutator\Operator\Spread::class,
         'Ternary' => Mutator\Operator\Ternary::class,
         'Throw_' => Mutator\Operator\Throw_::class,

tests/phpunit/Mutator/Operator/NullSafeMethodCallTest.php

@@ -0,0 +1,134 @@
+<?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;
+use const PHP_VERSION_ID;
+
+final class NullSafeMethodCallTest extends BaseMutatorTestCase
+{
+    /**
+     * @dataProvider mutationsProvider
+     *
+     * @param string|string[] $expected
+     */
+    public function test_it_can_mutate(string $input, $expected = []): void
+    {
+        if (PHP_VERSION_ID < 80000) {
+            $this->markTestSkipped('Null Safe operator is available only in PHP 8 or higher');
+        }
+
+        $this->doTest($input, $expected);
+    }
+
+    public function mutationsProvider(): iterable
+    {
+        yield 'Mutate nullsafe method call' => [
+            <<<'PHP'
+<?php
+
+$class?->getName();
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$class->getName();
+PHP
+        ];
+
+        yield 'Mutate nullsafe method call only' => [
+            <<<'PHP'
+<?php
+
+$class?->getName()?->property;
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$class->getName()?->property;
+PHP
+        ];
+
+        yield 'Mutate chain of nullsafe method calls' => [
+            <<<'PHP'
+<?php
+
+$class?->getObject()?->getName();
+PHP
+            ,
+            [
+                <<<'PHP'
+<?php
+
+$class->getObject()?->getName();
+PHP,
+                <<<'PHP'
+<?php
+
+$class?->getObject()->getName();
+PHP
+                ],
+        ];
+
+        yield 'Mutate nullsafe applied right when class has been instantiated' => [
+            <<<'PHP'
+<?php
+
+(new SomeClass())?->methodCall();
+PHP,
+            <<<'PHP'
+<?php
+
+(new SomeClass())->methodCall();
+PHP,
+        ];
+
+        yield 'Mutate nullsafe with dynamic method name' => [
+            <<<'PHP'
+<?php
+
+$class?->{$methodCall}();
+PHP,
+            <<<'PHP'
+<?php
+
+$class->{$methodCall}();
+PHP
+        ];
+    }
+}