From 9908744566240c247a9f3a77e68133e2ab2f04a3 Mon Sep 17 00:00:00 2001
From: Sandro Gehri <sandrogehri@gmail.com>
Date: Fri, 17 Nov 2023 13:55:19 +0100
Subject: [PATCH] Add Removal mutators

---
 WIP.md                                        |  1 -
 src/Mutators.php                              | 10 ++++
 src/Mutators/Removal/RemoveFunctionCall.php   | 41 ++++++++++++++
 src/Mutators/Removal/RemoveMethodCall.php     | 46 ++++++++++++++++
 src/Mutators/Sets/DefaultSet.php              |  1 +
 src/Mutators/Sets/RemovalSet.php              | 26 +++++++++
 src/Support/MutatorMap.php                    |  2 +
 src/Support/Printers/DefaultPrinter.php       |  2 +
 .../Removal/RemoveFunctionCallTest.php        | 17 ++++++
 .../Mutators/Removal/RemoveMethodCallTest.php | 53 +++++++++++++++++++
 10 files changed, 198 insertions(+), 1 deletion(-)
 create mode 100644 src/Mutators/Removal/RemoveFunctionCall.php
 create mode 100644 src/Mutators/Removal/RemoveMethodCall.php
 create mode 100644 src/Mutators/Sets/RemovalSet.php
 create mode 100644 tests/Mutators/Removal/RemoveFunctionCallTest.php
 create mode 100644 tests/Mutators/Removal/RemoveMethodCallTest.php

diff --git a/WIP.md b/WIP.md
index 9f79bc3..059c894 100644
--- a/WIP.md
+++ b/WIP.md
@@ -27,7 +27,6 @@
 - [ ] Awesome docs
 
 # Backlog Prio 1
-- [ ] Add return mutators
 - [ ] Add remove function call mutator
 - [ ] Add null safe mutators
 - [ ] Add array declaration mutators: https://stryker-mutator.io/docs/mutation-testing-elements/supported-mutators/#array-declaration
diff --git a/src/Mutators.php b/src/Mutators.php
index 1bff89a..d587560 100644
--- a/src/Mutators.php
+++ b/src/Mutators.php
@@ -126,6 +126,8 @@
 use Pest\Mutate\Mutators\Number\DecrementInteger;
 use Pest\Mutate\Mutators\Number\IncrementFloat;
 use Pest\Mutate\Mutators\Number\IncrementInteger;
+use Pest\Mutate\Mutators\Removal\RemoveFunctionCall;
+use Pest\Mutate\Mutators\Removal\RemoveMethodCall;
 use Pest\Mutate\Mutators\Return\AlwaysReturnEmptyArray;
 use Pest\Mutate\Mutators\Return\AlwaysReturnNull;
 use Pest\Mutate\Mutators\Sets\ArithmeticSet;
@@ -139,6 +141,7 @@
 use Pest\Mutate\Mutators\Sets\LogicalSet;
 use Pest\Mutate\Mutators\Sets\MathSet;
 use Pest\Mutate\Mutators\Sets\NumberSet;
+use Pest\Mutate\Mutators\Sets\RemovalSet;
 use Pest\Mutate\Mutators\Sets\ReturnSet;
 use Pest\Mutate\Mutators\Sets\StringSet;
 use Pest\Mutate\Mutators\Sets\VisibilitySet;
@@ -204,6 +207,8 @@ class Mutators
 
     final public const SET_NUMBER = NumberSet::class;
 
+    final public const SET_REMOVAL = RemovalSet::class;
+
     final public const SET_RETURN = ReturnSet::class;
 
     final public const SET_STRING = StringSet::class;
@@ -471,6 +476,11 @@ class Mutators
 
     final public const NUMBER_INCREMENT_INTEGER = IncrementInteger::class;
 
+    /** Removal */
+    final public const REMOVAL_REMOVE_FUNCTION_CALL = RemoveFunctionCall::class;
+
+    final public const REMOVAL_REMOVE_METHOD_CALL = RemoveMethodCall::class;
+
     /** Return */
     final public const RETURN_ALWAYS_RETURN_EMPTY_ARRAY = AlwaysReturnEmptyArray::class;
 
diff --git a/src/Mutators/Removal/RemoveFunctionCall.php b/src/Mutators/Removal/RemoveFunctionCall.php
new file mode 100644
index 0000000..6d9f677
--- /dev/null
+++ b/src/Mutators/Removal/RemoveFunctionCall.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Mutate\Mutators\Removal;
+
+use Pest\Mutate\Mutators\Abstract\AbstractMutator;
+use PhpParser\Node;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\Nop;
+
+class RemoveFunctionCall extends AbstractMutator
+{
+    public const SET = 'Removal';
+
+    public const DESCRIPTION = 'Removes a function call';
+
+    public const DIFF = <<<'DIFF'
+        foo();  // [tl! remove]
+        DIFF;
+
+    public static function nodesToHandle(): array
+    {
+        return [Expression::class];
+    }
+
+    public static function can(Node $node): bool
+    {
+        if (! $node instanceof Expression) {
+            return false;
+        }
+
+        return $node->expr instanceof FuncCall;
+    }
+
+    public static function mutate(Node $node): Node
+    {
+        return new Nop();
+    }
+}
diff --git a/src/Mutators/Removal/RemoveMethodCall.php b/src/Mutators/Removal/RemoveMethodCall.php
new file mode 100644
index 0000000..b67ebec
--- /dev/null
+++ b/src/Mutators/Removal/RemoveMethodCall.php
@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Mutate\Mutators\Removal;
+
+use Pest\Mutate\Mutators\Abstract\AbstractMutator;
+use PhpParser\Node;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Expr\StaticCall;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\Nop;
+
+class RemoveMethodCall extends AbstractMutator
+{
+    public const SET = 'Removal';
+
+    public const DESCRIPTION = 'Removes a method call';
+
+    public const DIFF = <<<'DIFF'
+        $this->foo();  // [tl! remove]
+        DIFF;
+
+    public static function nodesToHandle(): array
+    {
+        return [Expression::class];
+    }
+
+    public static function can(Node $node): bool
+    {
+        if (! $node instanceof Expression) {
+            return false;
+        }
+
+        if ($node->expr instanceof MethodCall) {
+            return true;
+        }
+
+        return $node->expr instanceof StaticCall;
+    }
+
+    public static function mutate(Node $node): Node
+    {
+        return new Nop();
+    }
+}
diff --git a/src/Mutators/Sets/DefaultSet.php b/src/Mutators/Sets/DefaultSet.php
index 06a409f..81f083f 100644
--- a/src/Mutators/Sets/DefaultSet.php
+++ b/src/Mutators/Sets/DefaultSet.php
@@ -26,6 +26,7 @@ public static function mutators(): array
             ...LogicalSet::mutators(),
             ...MathSet::mutators(),
             ...NumberSet::mutators(),
+            ...RemovalSet::mutators(),
             ...ReturnSet::mutators(),
             ...StringSet::mutators(),
             ...VisibilitySet::defaultMutators(),
diff --git a/src/Mutators/Sets/RemovalSet.php b/src/Mutators/Sets/RemovalSet.php
new file mode 100644
index 0000000..9b36339
--- /dev/null
+++ b/src/Mutators/Sets/RemovalSet.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Mutate\Mutators\Sets;
+
+use Pest\Mutate\Contracts\MutatorSet;
+use Pest\Mutate\Mutators\Concerns\HasName;
+use Pest\Mutate\Mutators\Removal\RemoveFunctionCall;
+use Pest\Mutate\Mutators\Removal\RemoveMethodCall;
+
+class RemovalSet implements MutatorSet
+{
+    use HasName;
+
+    /**
+     * {@inheritDoc}
+     */
+    public static function mutators(): array
+    {
+        return [
+            RemoveFunctionCall::class,
+            RemoveMethodCall::class,
+        ];
+    }
+}
diff --git a/src/Support/MutatorMap.php b/src/Support/MutatorMap.php
index 12b3ea8..f0459de 100644
--- a/src/Support/MutatorMap.php
+++ b/src/Support/MutatorMap.php
@@ -15,6 +15,7 @@
 use Pest\Mutate\Mutators\Sets\LogicalSet;
 use Pest\Mutate\Mutators\Sets\MathSet;
 use Pest\Mutate\Mutators\Sets\NumberSet;
+use Pest\Mutate\Mutators\Sets\RemovalSet;
 use Pest\Mutate\Mutators\Sets\ReturnSet;
 use Pest\Mutate\Mutators\Sets\StringSet;
 use Pest\Mutate\Mutators\Sets\VisibilitySet;
@@ -46,6 +47,7 @@ public static function get(): array
             ...LaravelSet::mutators(),
             ...MathSet::mutators(),
             ...NumberSet::mutators(),
+            ...RemovalSet::mutators(),
             ...ReturnSet::mutators(),
             ...StringSet::mutators(),
             ...VisibilitySet::mutators(),
diff --git a/src/Support/Printers/DefaultPrinter.php b/src/Support/Printers/DefaultPrinter.php
index 11a297f..b15afd0 100644
--- a/src/Support/Printers/DefaultPrinter.php
+++ b/src/Support/Printers/DefaultPrinter.php
@@ -142,9 +142,11 @@ private function writeMutationTestSummary(MutationTest $test): void
 
         $diff = '';
         foreach ($test->mutation->diff['modified'] as $line) {
+            $line = htmlentities($line); // TODO: this is not good, but currently required other printer breaks on `$this->foo()` because of the >
             $diff .= "<div class='text-green'>+ {$line}</div>";
         }
         foreach ($test->mutation->diff['original'] as $line) {
+            $line = htmlentities($line); // TODO: this is not good, but currently required other printer breaks on `$this->foo()` because of the >
             $diff .= "<div class='text-red'>- {$line}</div>";
         }
 
diff --git a/tests/Mutators/Removal/RemoveFunctionCallTest.php b/tests/Mutators/Removal/RemoveFunctionCallTest.php
new file mode 100644
index 0000000..25b20c8
--- /dev/null
+++ b/tests/Mutators/Removal/RemoveFunctionCallTest.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+use Pest\Mutate\Mutators\Removal\RemoveFunctionCall;
+
+it('removes a function call', function (): void {
+    expect(mutateCode(RemoveFunctionCall::class, <<<'CODE'
+        <?php
+
+        foo();
+        CODE))->toBe(<<<'CODE'
+        <?php
+        
+        
+        CODE);
+});
diff --git a/tests/Mutators/Removal/RemoveMethodCallTest.php b/tests/Mutators/Removal/RemoveMethodCallTest.php
new file mode 100644
index 0000000..5d300b7
--- /dev/null
+++ b/tests/Mutators/Removal/RemoveMethodCallTest.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+use Pest\Mutate\Mutators\Removal\RemoveMethodCall;
+
+it('removes a method call', function (): void {
+    expect(mutateCode(RemoveMethodCall::class, <<<'CODE'
+        <?php
+
+        class Foo
+        {
+            function foo()
+            {
+                $this->bar();
+            }
+        }
+        CODE))->toBe(<<<'CODE'
+        <?php
+        
+        class Foo
+        {
+            function foo()
+            {
+                
+            }
+        }
+        CODE);
+});
+
+it('removes a static method call', function (): void {
+    expect(mutateCode(RemoveMethodCall::class, <<<'CODE'
+        <?php
+
+        class Foo
+        {
+            function foo()
+            {
+                self::bar();
+            }
+        }
+        CODE))->toBe(<<<'CODE'
+        <?php
+        
+        class Foo
+        {
+            function foo()
+            {
+                
+            }
+        }
+        CODE);
+});