v.0.1

vendor/illuminate/support/Traits/ReflectsClosures.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace Illuminate\Support\Traits;
+
+use Closure;
+use Illuminate\Support\Reflector;
+use ReflectionFunction;
+use RuntimeException;
+
+trait ReflectsClosures
+{
+    /**
+     * Get the class names / types of the parameters of the given Closure.
+     *
+     * @param  \Closure  $closure
+     * @return array
+     *
+     * @throws \ReflectionException
+     */
+    protected function closureParameterTypes(Closure $closure)
+    {
+        $reflection = new ReflectionFunction($closure);
+
+        return collect($reflection->getParameters())->mapWithKeys(function ($parameter) {
+            if ($parameter->isVariadic()) {
+                return [$parameter->getName() => null];
+            }
+
+            return [$parameter->getName() => Reflector::getParameterClassName($parameter)];
+        })->all();
+    }
+
+    /**
+     * Get the class name of the first parameter of the given Closure.
+     *
+     * @param  \Closure  $closure
+     * @return string
+     *
+     * @throws \ReflectionException|\RuntimeException
+     */
+    protected function firstClosureParameterType(Closure $closure)
+    {
+        $types = array_values($this->closureParameterTypes($closure));
+
+        if (! $types) {
+            throw new RuntimeException('The given Closure has no parameters.');
+        }
+
+        if ($types[0] === null) {
+            throw new RuntimeException('The first parameter of the given Closure is missing a type hint.');
+        }
+
+        return $types[0];
+    }
+}