[8.x] Add route regex registration methods

src/Illuminate/Routing/PendingResourceRegistration.php

@@ -7,7 +7,7 @@
 
 class PendingResourceRegistration
 {
-    use Macroable;
+    use Macroable, RouteRegexConstraintTrait;
 
     /**
      * The resource registrar.

src/Illuminate/Routing/Route.php

@@ -21,7 +21,7 @@
 
 class Route
 {
-    use Macroable, RouteDependencyResolverTrait;
+    use Macroable, RouteDependencyResolverTrait, RouteRegexConstraintTrait;
 
     /**
      * The URI pattern the route responds to.

src/Illuminate/Routing/RouteRegexConstraintTrait.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Illuminate\Routing;
+
+trait RouteRegexConstraintTrait
+{
+    /**
+     * Apply a route regex requirement to the route.
+     *
+     * @param  array  $parameters
+     * @param  string $regex
+     * @return void
+     */
+    protected function applyRouteRegex(array $parameters, string $regex)
+    {
+        foreach ($parameters as $parameter) {
+            is_string($parameter)
+                ? $this->where([$parameter => $regex])
+                : $this->applyRouteRegex($parameter, $regex);
+        }
+    }
+
+    /**
+     * Set a number as regular expression requirement on the route.
+     *
+     * @param  string $parameters
+     * @return $this
+     */
+    public function whereNumber(...$parameters)
+    {
+        $this->applyRouteRegex($parameters, '[0-9]+');
+
+        return $this;
+    }
+
+    /**
+     * Set any character between a-z or A-Z as regular expression requirement on the route.
+     *
+     * @param  string|array $parameter
+     * @return $this
+     */
+    public function whereAlpha(...$parameters)
+    {
+        $this->applyRouteRegex($parameters, '[a-zA-Z]+');
+
+        return $this;
+    }
+}

tests/Routing/RouteRegistrarTest.php

@@ -594,6 +594,32 @@ public function testResourceWheres()
         }
     }
 
+    public function testWhereNumberRegistration()
+    {
+        $wheres = ['foo' => '[0-9]+', 'bar' => '[0-9]+'];
+
+        $this->router->get('/{foo}/{bar}')->whereNumber(['foo', 'bar']);
+        $this->router->get('/api/{bar}/{foo}')->whereNumber('bar', 'foo');
+
+        /** @var \Illuminate\Routing\Route $route */
+        foreach ($this->router->getRoutes() as $route) {
+            $this->assertEquals($wheres, $route->wheres);
+        }
+    }
+
+    public function testWhereAlphaRegistration()
+    {
+        $wheres = ['foo' => '[a-zA-Z]+', 'bar' => '[a-zA-Z]+'];
+
+        $this->router->get('/{foo}/{bar}')->whereAlpha(['foo', 'bar']);
+        $this->router->get('/api/{bar}/{foo}')->whereAlpha('bar', 'foo');
+
+        /** @var \Illuminate\Routing\Route $route */
+        foreach ($this->router->getRoutes() as $route) {
+            $this->assertEquals($wheres, $route->wheres);
+        }
+    }
+
     public function testCanSetRouteName()
     {
         $this->router->as('users.index')->get('users', function () {