New mutator for bcmath

composer.json

@@ -60,7 +60,8 @@
         "symfony/process": "3.4.2"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.5"
+        "phpunit/phpunit": "^7.5",
+        "ext-bcmath": "*"
     },
     "config": {
         "platform": {

devTools/Dockerfile-php71-xdebug

@@ -1,6 +1,7 @@
 FROM php:7.1-cli
 
-RUN pecl install xdebug && docker-php-ext-enable xdebug
+RUN pecl install xdebug && docker-php-ext-enable xdebug && \
+    docker-php-ext-install -j$(nproc) bcmath
 RUN apt-get update && apt-get install -y --no-install-recommends \
     expect git zip \
     && rm -rf /var/lib/apt/lists/*

devTools/Dockerfile-php72-xdebug

@@ -1,6 +1,7 @@
 FROM php:7.2-cli
 
-RUN pecl install xdebug && docker-php-ext-enable xdebug
+RUN pecl install xdebug && docker-php-ext-enable xdebug && \
+    docker-php-ext-install -j$(nproc) bcmath
 RUN apt-get update && apt-get install -y --no-install-recommends \
     expect git zip \
     && rm -rf /var/lib/apt/lists/*

devTools/Dockerfile-php73-xdebug

@@ -1,6 +1,7 @@
 FROM php:7.3-rc-cli
 
-RUN pecl install xdebug-beta && docker-php-ext-enable xdebug
+RUN pecl install xdebug-beta && docker-php-ext-enable xdebug && \
+    docker-php-ext-install -j$(nproc) bcmath
 RUN apt-get update && apt-get install -y --no-install-recommends \
     expect git zip \
     && rm -rf /var/lib/apt/lists/*

resources/schema.json

@@ -144,6 +144,54 @@
                             }
                         ]
                     }
+                },
+                "BCMath": {
+                    "type": {
+                        "anyOf": [
+                            {
+                                "type": "boolean"
+                            },
+                            {
+                                "type": "object",
+                                "additionalProperties": false,
+                                "properties": {
+                                    "settings": {
+                                        "type": "object",
+                                        "additionalProperties": false,
+                                        "properties": {
+                                            "bcadd": {
+                                                "type": "boolean"
+                                            },
+                                            "bccomp": {
+                                                "type": "boolean"
+                                            },
+                                            "bcdiv": {
+                                                "type": "boolean"
+                                            },
+                                            "bcmod": {
+                                                "type": "boolean"
+                                            },
+                                            "bcmul": {
+                                                "type": "boolean"
+                                            },
+                                            "bcpow": {
+                                                "type": "boolean"
+                                            },
+                                            "bcsub": {
+                                                "type": "boolean"
+                                            },
+                                            "bcsqrt": {
+                                                "type": "boolean"
+                                            },
+                                            "bcpowmod": {
+                                                "type": "boolean"
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        ]
+                    }
                 }
             }
         },

src/Mutator/Extensions/BCMath.php

@@ -0,0 +1,163 @@
+<?php
+/**
+ * This code is licensed under the BSD 3-Clause License.
+ *
+ * Copyright (c) 2017-2019, 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\Extensions;
+
+use Generator;
+use Infection\Mutator\Util\Mutator;
+use Infection\Mutator\Util\MutatorConfig;
+use PhpParser\Node;
+
+/**
+ * @internal
+ */
+final class BCMath extends Mutator
+{
+    private $converters;
+
+    public function __construct(MutatorConfig $config)
+    {
+        parent::__construct($config);
+
+        $settings = $this->getSettings();
+
+        $this->setupConverters($settings);
+    }
+
+    /**
+     * @param Node|Node\Expr\FuncCall $node
+     *
+     * @return Node|Node[]|Generator
+     */
+    public function mutate(Node $node)
+    {
+        yield from $this->converters[$node->name->toLowerString()]($node);
+    }
+
+    protected function mutatesNode(Node $node): bool
+    {
+        if (!$node instanceof Node\Expr\FuncCall || !$node->name instanceof Node\Name) {
+            return false;
+        }
+
+        $functionName = $node->name->toLowerString();
+
+        return isset($this->converters[$functionName]) && \function_exists($functionName);
+    }
+
+    private function setupConverters(array $functionsMap): void
+    {
+        $converters = [
+            'bcadd' => $this->mapCheckingMinArgs(2, $this->mapCastToString(
+                $this->mapBinaryOperator(Node\Expr\BinaryOp\Plus::class)
+            )),
+            'bcdiv' => $this->mapCheckingMinArgs(2, $this->mapCastToString(
+                $this->mapBinaryOperator(Node\Expr\BinaryOp\Div::class)
+            )),
+            'bcmod' => $this->mapCheckingMinArgs(2, $this->mapCastToString(
+                $this->mapBinaryOperator(Node\Expr\BinaryOp\Mod::class)
+            )),
+            'bcmul' => $this->mapCheckingMinArgs(2, $this->mapCastToString(
+                $this->mapBinaryOperator(Node\Expr\BinaryOp\Mul::class)
+            )),
+            'bcpow' => $this->mapCheckingMinArgs(2, $this->mapCastToString(
+                $this->mapBinaryOperator(Node\Expr\BinaryOp\Pow::class)
+            )),
+            'bcsub' => $this->mapCheckingMinArgs(2, $this->mapCastToString(
+                $this->mapBinaryOperator(Node\Expr\BinaryOp\Minus::class)
+            )),
+            'bcsqrt' => $this->mapCheckingMinArgs(1, $this->mapCastToString(
+                $this->mapSquareRoots()
+            )),
+            'bcpowmod' => $this->mapCheckingMinArgs(3, $this->mapCastToString(
+                $this->mapPowerModulo()
+            )),
+            'bccomp' => $this->mapCheckingMinArgs(2,
+                $this->mapBinaryOperator(Node\Expr\BinaryOp\Spaceship::class)
+            ),
+        ];
+
+        $functionsToRemove = \array_filter($functionsMap, static function ($isOn) {
+            return !$isOn;
+        });
+
+        $this->converters = \array_diff_key($converters, $functionsToRemove);
+    }
+
+    private function mapCheckingMinArgs(int $minimumArgsCount, callable $converter)
+    {
+        return static function (Node\Expr\FuncCall $node) use ($minimumArgsCount, $converter): Generator {
+            if (\count($node->args) >= $minimumArgsCount) {
+                yield from $converter($node);
+            }
+        };
+    }
+
+    private function mapCastToString(callable $converter): callable
+    {
+        return static function (Node\Expr\FuncCall $node) use ($converter): Generator {
+            foreach ($converter($node) as $newNode) {
+                yield new Node\Expr\Cast\String_($newNode);
+            }
+        };
+    }
+
+    private function mapBinaryOperator(string $operator): callable
+    {
+        return static function (Node\Expr\FuncCall $node) use ($operator): Generator {
+            yield new $operator($node->args[0]->value, $node->args[1]->value);
+        };
+    }
+
+    private function mapSquareRoots(): callable
+    {
+        return static function (Node\Expr\FuncCall $node): Generator {
+            yield new Node\Expr\FuncCall(new Node\Name('\sqrt'), [$node->args[0]]);
+        };
+    }
+
+    private function mapPowerModulo(): callable
+    {
+        return static function (Node\Expr\FuncCall $node): Generator {
+            yield new Node\Expr\BinaryOp\Mod(
+                new Node\Expr\FuncCall(
+                    new Node\Name('\pow'),
+                    [$node->args[0], $node->args[1]]
+                ),
+                $node->args[2]->value
+            );
+        };
+    }
+}

src/Mutator/Util/MutatorProfile.php

@@ -232,6 +232,10 @@ final class MutatorProfile
         Mutator\Unwrap\UnwrapUcWords::class,
     ];
 
+    public const EXTENSIONS = [
+        Mutator\Extensions\BCMath::class,
+    ];
+
     public const DEFAULT = [
         '@arithmetic',
         '@boolean',
@@ -395,5 +399,8 @@ final class MutatorProfile
         'UnwrapTrim' => Mutator\Unwrap\UnwrapTrim::class,
         'UnwrapUcFirst' => Mutator\Unwrap\UnwrapUcFirst::class,
         'UnwrapUcWords' => Mutator\Unwrap\UnwrapUcWords::class,
+
+        // Extensions
+        'BCMath' => Mutator\Extensions\BCMath::class,
     ];
 }