Make middleware more like react/http middleware

Where you nest them like an union.

Author: WyriHaximus

src/Client.php

@@ -7,10 +7,12 @@
 use PgAsync\Client as PgClient;
 use Plasma\SQL\Grammar\PostgreSQL;
 use Plasma\SQL\QueryBuilder;
+use React\Promise\PromiseInterface;
 use Rx\Observable;
 use WyriHaximus\React\SimpleORM\Middleware\ExecuteQueryMiddleware;
 use WyriHaximus\React\SimpleORM\Middleware\GrammarMiddleware;
 use function ApiClients\Tools\Rx\unwrapObservableFromPromise;
+use function React\Promise\resolve;
 
 final class Client implements ClientInterface
 {
@@ -51,7 +53,6 @@ private function __construct(PgClient $client, Reader $annotationReader, Middlew
         $this->entityInspector = new EntityInspector($annotationReader);
 
         $middleware[] = new GrammarMiddleware(new PostgreSQL());
-        $middleware[] = new ExecuteQueryMiddleware($this->client);
 
         $this->middlewareRunner = new MiddlewareRunner(...$middleware);
     }
@@ -67,6 +68,12 @@ public function getRepository(string $entity): RepositoryInterface
 
     public function query(QueryBuilder $query): Observable
     {
-        return unwrapObservableFromPromise($this->middlewareRunner->query($query));
+        return unwrapObservableFromPromise($this->middlewareRunner->query(
+            $query,
+            function (QueryBuilder $query): PromiseInterface
+            {
+                return resolve($this->client->executeStatement($query->getQuery(), $query->getParameters()));
+            }
+        ));
     }
 }

src/Middleware/ExecuteQueryMiddleware.php

@@ -18,8 +18,8 @@ public function __construct(GrammarInterface $grammer)
         $this->grammer = $grammer;
     }
 
-    public function query(QueryBuilder $query): PromiseInterface
+    public function query(QueryBuilder $query, callable $next): PromiseInterface
     {
-        return resolve($query->withGrammar($this->grammer));
+        return resolve($next($query->withGrammar($this->grammer)));
     }
 }

src/Middleware/GrammarMiddleware.php

@@ -15,11 +15,11 @@ final class QueryCountMiddleware implements MiddlewareInterface
     /** @var int */
     private $count = self::ZERO;
 
-    public function query(QueryBuilder $query): PromiseInterface
+    public function query(QueryBuilder $query, callable $next): PromiseInterface
     {
         $this->count++;
 
-        return resolve($query);
+        return resolve($next($query))->then();
     }
 
     public function getCount(): int

src/Middleware/QueryCountMiddleware.php

@@ -11,8 +11,9 @@ interface MiddlewareInterface
      * Returns the (modified) query through a promise.
      *
      * @param QueryBuilder $query
+     * @param callable $next
      *
      * @return PromiseInterface
      */
-    public function query(QueryBuilder $query): PromiseInterface;
+    public function query(QueryBuilder $query, callable $next): PromiseInterface;
 }

src/MiddlewareInterface.php

@@ -9,6 +9,7 @@
 /**
  * @internal
  */
+
 final class MiddlewareRunner
 {
     /** @var MiddlewareInterface[] */
@@ -22,20 +23,20 @@ public function __construct(MiddlewareInterface ...$middleware)
         $this->middleware = $middleware;
     }
 
-    public function query(QueryBuilder $query): PromiseInterface
+    public function query(QueryBuilder $query, callable $last): PromiseInterface
     {
-        return $this->call($query, 0);
+        return $this->call($query, 0, $last);
     }
 
-    private function call(QueryBuilder $query, int $position): PromiseInterface
+    private function call(QueryBuilder $query, int $position, callable $last): PromiseInterface
     {
         // final request handler will be invoked without hooking into the promise
         if (!array_key_exists($position + 1, $this->middleware)) {
-            return $this->middleware[$position]->query($query);
+            return $this->middleware[$position]->query($query, $last);
         }
 
-        return $this->middleware[$position]->query($query)->then(function (QueryBuilder $query) use ($position) {
-            return $this->call($query, $position + 1);
+        return $this->middleware[$position]->query($query, function (QueryBuilder $query) use ($position, $last) {
+            return $this->call($query, $position + 1, $last);
         });
     }
 }

src/MiddlewareRunner.php

@@ -4,8 +4,11 @@
 
 use Plasma\SQL\GrammarInterface;
 use Plasma\SQL\QueryBuilder;
+use Rx\Observable;
+use Rx\ObservableInterface;
 use WyriHaximus\AsyncTestUtilities\AsyncTestCase;
 use WyriHaximus\React\SimpleORM\Middleware\GrammarMiddleware;
+use function ApiClients\Tools\Rx\observableFromArray;
 
 /**
  * @internal
@@ -20,8 +23,15 @@ public function testInsertedGrammar(): void
         $query = $this->prophesize(QueryBuilder::class);
         $query->withGrammar($grammar->reveal())->shouldBeCalled()->willReturn($query->reveal());
 
-        $queryWithGrammar = $this->await($middleware->query($query->reveal()));
+        $nextCount = false;
+        $observable = $this->await($middleware->query($query->reveal(), function () use (&$nextCount) {
+            $nextCount = true;
 
-        self::assertSame($query->reveal(), $queryWithGrammar);
+            return observableFromArray([]);
+        }));
+
+        self::assertTrue($nextCount);
+        self::assertInstanceOf(ObservableInterface::class, $observable);
+        self::assertInstanceOf(Observable::class, $observable);
     }
 }

tests/Middleware/ExecuteQueryMiddlewareTest.php

@@ -22,7 +22,7 @@ public function testCounting(): void
 
         self::assertSame(0, $middleware->getCount());
 
-        $middleware->query(QueryBuilder::create());
+        $middleware->query(QueryBuilder::create(), function () {});
 
         self::assertSame(1, $middleware->getCount());