Add Ternary operator mutator

resources/schema.json

@@ -244,6 +244,7 @@
                 "AssignCoalesce": { "$ref": "#/definitions/default-mutator-config" },
                 "Break_": { "$ref": "#/definitions/default-mutator-config" },
                 "Continue_": { "$ref": "#/definitions/default-mutator-config" },
+                "Ternary": { "$ref": "#/definitions/default-mutator-config" },
                 "Throw_": { "$ref": "#/definitions/default-mutator-config" },
                 "Finally_": { "$ref": "#/definitions/default-mutator-config" },
                 "Coalesce": { "$ref": "#/definitions/default-mutator-config" },

src/Mutator/Operator/Ternary.php

@@ -0,0 +1,85 @@
+<?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 PhpParser\Node;
+
+/**
+ * @internal
+ */
+final class Ternary implements Mutator
+{
+    use GetMutatorName;
+
+    public static function getDefinition(): ?Definition
+    {
+        return new Definition(
+            <<<'TXT'
+Swaps the ternary operator operands, e.g. replaces `true ? true : false` with `true ? false : true`.
+TXT
+            ,
+            MutatorCategory::ORTHOGONAL_REPLACEMENT,
+            null
+        );
+    }
+
+    public function canMutate(Node $node): bool
+    {
+        return $node instanceof Node\Expr\Ternary;
+    }
+
+    /**
+     * @psalm-mutation-free
+     *
+     * @param Node\Expr\Ternary $node
+     *
+     * @return iterable<Node\Expr>
+     */
+    public function mutate(Node $node): iterable
+    {
+        $if = $node->if;
+
+        if ($if === null) {
+            $if = $node->cond;
+        }
+
+        yield new Node\Expr\Ternary($node->cond, $node->else, $if, $node->getAttributes());
+    }
+}

src/Mutator/ProfileList.php

@@ -158,6 +158,7 @@ final class ProfileList
         Mutator\Operator\Finally_::class,
         Mutator\Operator\FlipCoalesce::class,
         Mutator\Operator\Spread::class,
+        Mutator\Operator\Ternary::class,
         Mutator\Operator\Throw_::class,
     ];
 
@@ -347,6 +348,7 @@ final class ProfileList
         'Finally_' => Mutator\Operator\Finally_::class,
         'FlipCoalesce' => Mutator\Operator\FlipCoalesce::class,
         'Spread' => Mutator\Operator\Spread::class,
+        'Ternary' => Mutator\Operator\Ternary::class,
         'Throw_' => Mutator\Operator\Throw_::class,
 
         // Regex

tests/phpunit/Mutator/Operator/TernaryTest.php

@@ -0,0 +1,174 @@
+<?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 TernaryTest extends BaseMutatorTestCase
+{
+    /**
+     * @dataProvider mutationsProvider
+     *
+     * @param string|string[] $expected
+     */
+    public function test_it_can_mutate(string $input, $expected = []): void
+    {
+        $this->doTest($input, $expected);
+    }
+
+    public function mutationsProvider(): iterable
+    {
+        yield 'Mutates ternary and flip conditions' => [
+            <<<'PHP'
+<?php
+
+isset($b) ? 'B' : 'C';
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+isset($b) ? 'C' : 'B';
+PHP
+        ];
+
+        yield 'asd' => [
+            <<<'PHP'
+<?php
+
+$foo = 'foo';
+$foo ?: 'bar';
+PHP
+            ,
+            <<<'PHP'
+<?php
+
+$foo = 'foo';
+$foo ? 'bar' : $foo;
+PHP
+        ];
+
+        if (PHP_VERSION_ID < 80000) {
+            yield 'Mutates nested ternary expression with values in the if condition' => [
+                <<<'PHP'
+<?php
+
+true ? 'true' : false ? 't' : 'f';
+PHP
+                ,
+                [
+                    <<<'PHP'
+<?php
+
+true ? false : 'true' ? 't' : 'f';
+PHP
+                    ,
+                    <<<'PHP'
+<?php
+
+true ? 'true' : false ? 'f' : 't';
+PHP
+                ],
+            ];
+
+            yield 'Mutates nested ternary expression without values in the if condition' => [
+                <<<'PHP'
+<?php
+
+true ?: false ?: 'f';
+PHP
+                ,
+                [
+                    <<<'PHP'
+<?php
+
+true ? false : true ?: 'f';
+PHP
+                    ,
+                    <<<'PHP'
+<?php
+
+true ?: false ? 'f' : (true ?: false);
+PHP
+                ],
+            ];
+
+            yield 'Mutates wrapped in braces ternary expressions with values in the if condition' => [
+                <<<'PHP'
+<?php
+
+(true ? 'true' : false) ? 't' : 'f';
+PHP
+                ,
+                [
+                    <<<'PHP'
+<?php
+
+true ? false : 'true' ? 't' : 'f';
+PHP
+                    ,
+                    <<<'PHP'
+<?php
+
+true ? 'true' : false ? 'f' : 't';
+PHP
+                ],
+            ];
+
+            yield 'Mutates wrapped in braces ternary expressions without values in the if condition' => [
+                <<<'PHP'
+<?php
+
+((true ?: false) ? 't' : 'f');
+PHP
+                ,
+                [
+                    <<<'PHP'
+<?php
+
+true ? false : true ? 't' : 'f';
+PHP
+                    ,
+                    <<<'PHP'
+<?php
+
+true ?: false ? 'f' : 't';
+PHP
+                ],
+            ];
+        }
+    }
+}