Family of MethodCall Mutators

These mutators replace any method or function call with `null`, `true`, or `false`.
This way even if a method/funcion call is embedded in other construct, be it an `if`
or another method call, there won't be a language error.

src/Mutator/Statement/MethodCallFalse.php

@@ -0,0 +1,15 @@
+<?php
+/**
+ * Copyright © 2017-2018 Maks Rafalko
+ *
+ * License: https://opensource.org/licenses/BSD-3-Clause New BSD License
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Mutator\Statement;
+
+class MethodCallFalse extends MethodCallTrue
+{
+    const REPLACEMENT = 'false';
+}

src/Mutator/Statement/MethodCallNull.php

@@ -0,0 +1,15 @@
+<?php
+/**
+ * Copyright © 2017-2018 Maks Rafalko
+ *
+ * License: https://opensource.org/licenses/BSD-3-Clause New BSD License
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Mutator\Statement;
+
+class MethodCallNull extends MethodCallTrue
+{
+    const REPLACEMENT = 'null';
+}

src/Mutator/Statement/MethodCallTrue.php

@@ -0,0 +1,28 @@
+<?php
+/**
+ * Copyright © 2017-2018 Maks Rafalko
+ *
+ * License: https://opensource.org/licenses/BSD-3-Clause New BSD License
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Mutator\Statement;
+
+use Infection\Mutator\Util\Mutator;
+use PhpParser\Node;
+
+class MethodCallTrue extends Mutator
+{
+    const REPLACEMENT = 'true';
+
+    public function mutate(Node $node)
+    {
+        return new Node\Expr\ConstFetch(new Node\Name(static::REPLACEMENT));
+    }
+
+    public function shouldMutate(Node $node): bool
+    {
+        return $node instanceof Node\Expr\MethodCall || $node instanceof Node\Expr\FuncCall;
+    }
+}

src/Mutator/Util/MutatorProfile.php

@@ -116,6 +116,9 @@ final class MutatorProfile
 
     const STATEMENT = [
         Mutator\Statement\Assign::class,
+        Mutator\Statement\MethodCallFalse::class,
+        Mutator\Statement\MethodCallNull::class,
+        Mutator\Statement\MethodCallTrue::class,
     ];
 
     const ZERO_ITERATION = [
@@ -214,6 +217,9 @@ final class MutatorProfile
 
         //Statement
         'Assign' => Mutator\Statement\Assign::class,
+        'MethodCallFalse' => Mutator\Statement\MethodCallFalse::class,
+        'MethodCallNull' => Mutator\Statement\MethodCallNull::class,
+        'MethodCallTrue' => Mutator\Statement\MethodCallTrue::class,
 
         //Zero Iteration
         'Foreach_' => Mutator\ZeroIteration\Foreach_::class,

tests/Mutator/Statement/MethodCallFalseTest.php

@@ -0,0 +1,63 @@
+<?php
+/**
+ * Copyright © 2017-2018 Maks Rafalko
+ *
+ * License: https://opensource.org/licenses/BSD-3-Clause New BSD License
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Tests\Mutator\Statement;
+
+use Infection\Tests\Mutator\AbstractMutatorTestCase;
+
+class MethodCallFalseTest extends AbstractMutatorTestCase
+{
+    /**
+     * @dataProvider provideMutationCases
+     */
+    public function test_mutator($input, $expected = null)
+    {
+        $this->doTest($input, $expected);
+    }
+
+    public function provideMutationCases(): array
+    {
+        return [
+            'It removes method calls' => [
+                <<<'PHP'
+<?php
+
+bar();
+$a = bar();
+$var->foo();
+$var->foo() == 1;
+$var->foo()->bar();
+$var->foo()->bar()->baz();
+$var->foo()->bar()->baz() == $var;
+if ($var->foo()) {
+}
+if ($var->foo()->bar() == 1) {
+}
+PHP
+                ,
+                <<<'PHP'
+<?php
+
+false;
+$a = false;
+false;
+false == 1;
+false;
+false;
+false == $var;
+if (false) {
+}
+if (false == 1) {
+}
+PHP
+                ,
+            ],
+        ];
+    }
+}

tests/Mutator/Statement/MethodCallNullTest.php

@@ -0,0 +1,63 @@
+<?php
+/**
+ * Copyright © 2017-2018 Maks Rafalko
+ *
+ * License: https://opensource.org/licenses/BSD-3-Clause New BSD License
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Tests\Mutator\Statement;
+
+use Infection\Tests\Mutator\AbstractMutatorTestCase;
+
+class MethodCallNullTest extends AbstractMutatorTestCase
+{
+    /**
+     * @dataProvider provideMutationCases
+     */
+    public function test_mutator($input, $expected = null)
+    {
+        $this->doTest($input, $expected);
+    }
+
+    public function provideMutationCases(): array
+    {
+        return [
+            'It removes method calls' => [
+                <<<'PHP'
+<?php
+
+bar();
+$a = bar();
+$var->foo();
+$var->foo() == 1;
+$var->foo()->bar();
+$var->foo()->bar()->baz();
+$var->foo()->bar()->baz() == $var;
+if ($var->foo()) {
+}
+if ($var->foo()->bar() == 1) {
+}
+PHP
+                ,
+                <<<'PHP'
+<?php
+
+null;
+$a = null;
+null;
+null == 1;
+null;
+null;
+null == $var;
+if (null) {
+}
+if (null == 1) {
+}
+PHP
+                ,
+            ],
+        ];
+    }
+}

tests/Mutator/Statement/MethodCallTrueTest.php

@@ -0,0 +1,63 @@
+<?php
+/**
+ * Copyright © 2017-2018 Maks Rafalko
+ *
+ * License: https://opensource.org/licenses/BSD-3-Clause New BSD License
+ */
+
+declare(strict_types=1);
+
+namespace Infection\Tests\Mutator\Statement;
+
+use Infection\Tests\Mutator\AbstractMutatorTestCase;
+
+class MethodCallTrueTest extends AbstractMutatorTestCase
+{
+    /**
+     * @dataProvider provideMutationCases
+     */
+    public function test_mutator($input, $expected = null)
+    {
+        $this->doTest($input, $expected);
+    }
+
+    public function provideMutationCases(): array
+    {
+        return [
+            'It removes method calls' => [
+                <<<'PHP'
+<?php
+
+bar();
+$a = bar();
+$var->foo();
+$var->foo() == 1;
+$var->foo()->bar();
+$var->foo()->bar()->baz();
+$var->foo()->bar()->baz() == $var;
+if ($var->foo()) {
+}
+if ($var->foo()->bar() == 1) {
+}
+PHP
+                ,
+                <<<'PHP'
+<?php
+
+true;
+$a = true;
+true;
+true == 1;
+true;
+true;
+true == $var;
+if (true) {
+}
+if (true == 1) {
+}
+PHP
+                ,
+            ],
+        ];
+    }
+}