[12.x] Bind abstract from concrete's return type (#54628)

* Proof of concept

* formatting

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: peterfox

src/Illuminate/Container/Container.php

@@ -9,12 +9,15 @@
 use Illuminate\Contracts\Container\CircularDependencyException;
 use Illuminate\Contracts\Container\Container as ContainerContract;
 use Illuminate\Contracts\Container\ContextualAttribute;
+use Illuminate\Support\Collection;
 use LogicException;
 use ReflectionAttribute;
 use ReflectionClass;
 use ReflectionException;
 use ReflectionFunction;
+use ReflectionIntersectionType;
 use ReflectionParameter;
+use ReflectionUnionType;
 use TypeError;
 
 class Container implements ArrayAccess, ContainerContract
@@ -268,15 +271,22 @@ public function isAlias($name)
     /**
      * Register a binding with the container.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @param  bool  $shared
      * @return void
      *
      * @throws \TypeError
+     * @throws ReflectionException
      */
     public function bind($abstract, $concrete = null, $shared = false)
     {
+        if ($abstract instanceof Closure) {
+            return $this->bindBasedOnClosureReturnTypes(
+                $abstract, $concrete, $shared
+            );
+        }
+
         $this->dropStaleInstances($abstract);
 
         // If no concrete type was given, we will simply set the concrete type to the
@@ -381,7 +391,7 @@ public function callMethodBinding($method, $instance)
      * Add a contextual binding to the container.
      *
      * @param  string  $concrete
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string  $implementation
      * @return void
      */
@@ -393,7 +403,7 @@ public function addContextualBinding($concrete, $abstract, $implementation)
     /**
      * Register a binding if it hasn't already been registered.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @param  bool  $shared
      * @return void
@@ -408,7 +418,7 @@ public function bindIf($abstract, $concrete = null, $shared = false)
     /**
      * Register a shared binding in the container.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -420,7 +430,7 @@ public function singleton($abstract, $concrete = null)
     /**
      * Register a shared binding if it hasn't already been registered.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -434,7 +444,7 @@ public function singletonIf($abstract, $concrete = null)
     /**
      * Register a scoped binding in the container.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -448,7 +458,7 @@ public function scoped($abstract, $concrete = null)
     /**
      * Register a scoped binding if it hasn't already been registered.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -459,6 +469,54 @@ public function scopedIf($abstract, $concrete = null)
         }
     }
 
+    /**
+     * Register a binding with the container based on the given Closure's return types.
+     *
+     * @param  \Closure|string  $abstract
+     * @param  \Closure|string|null  $concrete
+     * @param  bool  $shared
+     * @return void
+     */
+    protected function bindBasedOnClosureReturnTypes($abstract, $concrete = null, $shared = false)
+    {
+        $abstracts = $this->closureReturnTypes($abstract);
+
+        $concrete = $abstract;
+
+        foreach ($abstracts as $abstract) {
+            $this->bind($abstract, $concrete, $shared);
+        }
+    }
+
+    /**
+     * Get the class names / types of the return type of the given Closure.
+     *
+     * @param  \Closure  $closure
+     * @return list<class-string>
+     *
+     * @throws \ReflectionException
+     */
+    protected function closureReturnTypes(Closure $closure)
+    {
+        $reflection = new ReflectionFunction($closure);
+
+        if ($reflection->getReturnType() === null ||
+            $reflection->getReturnType() instanceof ReflectionIntersectionType) {
+            return [];
+        }
+
+        $types = $reflection->getReturnType() instanceof ReflectionUnionType
+            ? $reflection->getReturnType()->getTypes()
+            : [$reflection->getReturnType()];
+
+        return (new Collection($types))
+            ->reject(fn ($type) => $type->isBuiltin())
+            ->reject(fn ($type) => in_array($type->getName(), ['static', 'self']))
+            ->map(fn ($type) => $type->getName())
+            ->values()
+            ->all();
+    }
+
     /**
      * "Extend" an abstract type in the container.
      *

src/Illuminate/Contracts/Container/Container.php

@@ -56,7 +56,7 @@ public function tagged($tag);
     /**
      * Register a binding with the container.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @param  bool  $shared
      * @return void
@@ -75,7 +75,7 @@ public function bindMethod($method, $callback);
     /**
      * Register a binding if it hasn't already been registered.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @param  bool  $shared
      * @return void
@@ -85,7 +85,7 @@ public function bindIf($abstract, $concrete = null, $shared = false);
     /**
      * Register a shared binding in the container.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -94,7 +94,7 @@ public function singleton($abstract, $concrete = null);
     /**
      * Register a shared binding if it hasn't already been registered.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -103,7 +103,7 @@ public function singletonIf($abstract, $concrete = null);
     /**
      * Register a scoped binding in the container.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -112,7 +112,7 @@ public function scoped($abstract, $concrete = null);
     /**
      * Register a scoped binding if it hasn't already been registered.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string|null  $concrete
      * @return void
      */
@@ -121,7 +121,7 @@ public function scopedIf($abstract, $concrete = null);
     /**
      * "Extend" an abstract type in the container.
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure  $closure
      * @return void
      *
@@ -134,7 +134,7 @@ public function extend($abstract, Closure $closure);
      *
      * @template TInstance of mixed
      *
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  TInstance  $instance
      * @return TInstance
      */
@@ -144,7 +144,7 @@ public function instance($abstract, $instance);
      * Add a contextual binding to the container.
      *
      * @param  string  $concrete
-     * @param  string  $abstract
+     * @param  \Closure|string  $abstract
      * @param  \Closure|string  $implementation
      * @return void
      */

tests/Container/ContainerTest.php

@@ -40,6 +40,24 @@ public function testClosureResolution()
         $this->assertSame('Taylor', $container->make('name'));
     }
 
+    public function testAbstractCanBeBoundFromConcreteReturnType()
+    {
+        $container = new Container;
+        $container->bind(function (): IContainerContractStub|ContainerImplementationStub {
+            return new ContainerImplementationStub;
+        });
+        $container->singleton(function (): ContainerConcreteStub {
+            return new ContainerConcreteStub;
+        });
+
+        $this->assertInstanceOf(
+            IContainerContractStub::class,
+            $container->make(IContainerContractStub::class)
+        );
+
+        $this->assertTrue($container->isShared(ContainerConcreteStub::class));
+    }
+
     public function testBindIfDoesntRegisterIfServiceAlreadyRegistered()
     {
         $container = new Container;