add TernaryToElvisRector

config/level/php/php53.yml

@@ -0,0 +1,2 @@
+services:
+    Rector\CodeQuality\Rector\Ternary\TernaryToElvisRector: ~

packages/CodeQuality/src/Rector/Ternary/TernaryToElvisRector.php

@@ -0,0 +1,59 @@
+<?php declare(strict_types=1);
+
+namespace Rector\CodeQuality\Rector\Ternary;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Ternary;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+/**
+ * @see http://php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary
+ * @see https://stackoverflow.com/a/1993455/1348344
+ */
+final class TernaryToElvisRector extends AbstractRector
+{
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Use ?: instead of ?, where useful', [
+            new CodeSample(
+                <<<'CODE_SAMPLE'
+function elvis()
+{
+    $value = $a ? $a : false;
+}
+CODE_SAMPLE
+                ,
+                <<<'CODE_SAMPLE'
+function elvis()
+{
+    $value = $a ?: false;
+}
+CODE_SAMPLE
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [Ternary::class];
+    }
+
+    /**
+     * @param Ternary $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if (! $this->areNodesEqual($node->cond, $node->if)) {
+            return null;
+        }
+
+        $node->if = null;
+
+        return $node;
+    }
+}

packages/CodeQuality/tests/Rector/Ternary/TernaryToElvisRector/Fixture/fixture.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+function elvis()
+{
+    $value = $a ? $a : false;
+}
+
+?>
+-----
+<?php
+
+function elvis()
+{
+    $value = $a ?: false;
+}
+
+?>

packages/CodeQuality/tests/Rector/Ternary/TernaryToElvisRector/TernaryToElvisRectorTest.php

@@ -0,0 +1,19 @@
+<?php declare(strict_types=1);
+
+namespace Rector\CodeQuality\Tests\Rector\Ternary\TernaryToElvisRector;
+
+use Rector\CodeQuality\Rector\Ternary\TernaryToElvisRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class TernaryToElvisRectorTest extends AbstractRectorTestCase
+{
+    public function test(): void
+    {
+        $this->doTestFiles([__DIR__ . '/Fixture/fixture.php.inc']);
+    }
+
+    protected function getRectorClass(): string
+    {
+        return TernaryToElvisRector::class;
+    }
+}

packages/CodeQuality/tests/Rector/Ternary/TernaryToElvisRector/config.yml

@@ -0,0 +1,2 @@
+services:
+    Rector\CodeQuality\Rector\Ternary\TernaryToElvisRector: ~