Bind default WorkflowRepositoryInterface in package provider

On a fresh composer install, only the package's WaterlineServiceProvider
is auto-loaded. The host app has not yet published or registered its own
WaterlineApplicationServiceProvider subclass, so the
WorkflowRepositoryInterface binding — previously defined only in
WaterlineApplicationServiceProvider::register() — is absent. Any request
to /waterline/api/stats or the flow list endpoints hits a 500 with
"Target [Waterline\Repositories\Workflow\Interfaces\WorkflowRepositoryInterface]
is not instantiable".

Move the default resolver binding into the package provider's register()
method using bindIf. A published WaterlineApplicationServiceProvider
subclass that binds its own implementation still takes precedence
because bindIf defers to any existing binding.

Also mirror the Workflow\Models\Model class alias shim so both the
package provider and the Application provider remain safe to register in
either order. The new testPackageRegisterBindsDefaultRepositoryWithoutApplicationProvider
covers the fresh-install path and testPackageRegisterLeavesHostAppBindingInPlace
covers the user-override path.

Author: durable-workflow-ops

app/WaterlineServiceProvider.php

@@ -2,9 +2,20 @@
 
 namespace Waterline;
 
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Route;
 use Illuminate\Support\ServiceProvider;
+use Waterline\Repositories\Workflow\Infrastructure\UnavailableV2WorkflowRepository;
+use Waterline\Repositories\Workflow\Infrastructure\V2WorkflowRepository;
+use Waterline\Repositories\Workflow\Infrastructure\WorkflowRepositoryMySQL;
+use Waterline\Repositories\Workflow\Infrastructure\WorkflowRepositoryPostgreSQL;
+use Waterline\Repositories\Workflow\Infrastructure\WorkflowRepositorySQLite;
+use Waterline\Repositories\Workflow\Infrastructure\WorkflowRepositorySQLServer;
+use Waterline\Repositories\Workflow\Interfaces\WorkflowRepositoryInterface;
+use Waterline\Support\WorkflowEngineSourceResolver;
 use Waterline\Support\WorkflowPackageApiFloor;
+use Workflow\Models\StoredWorkflow;
 
 class WaterlineServiceProvider extends ServiceProvider
 {
@@ -112,5 +123,40 @@ public function register()
         if (! defined('WATERLINE_PATH')) {
             define('WATERLINE_PATH', realpath(__DIR__.'/../'));
         }
+
+        if (! class_exists('Workflow\Models\Model')) {
+            class_alias(config('workflows.base_model', Model::class), 'Workflow\Models\Model');
+        }
+
+        // Bind the default WorkflowRepositoryInterface resolver so Waterline
+        // routes work on a fresh composer install without requiring the host
+        // app to publish and register WaterlineApplicationServiceProvider
+        // first. Published provider subclasses that bind their own
+        // implementation in register() still take precedence because bindIf()
+        // defers to any pre-existing binding.
+        $this->app->bindIf(WorkflowRepositoryInterface::class, static function () {
+            $engineSource = WorkflowEngineSourceResolver::status();
+
+            if (($engineSource['uses_v2'] ?? false) === true) {
+                return app(V2WorkflowRepository::class);
+            }
+
+            if (($engineSource['resolved'] ?? null) === 'v2') {
+                return new UnavailableV2WorkflowRepository($engineSource);
+            }
+
+            $drivers = [
+                'mysql' => WorkflowRepositoryMySQL::class,
+                'pgsql' => WorkflowRepositoryPostgreSQL::class,
+                'sqlite' => WorkflowRepositorySQLite::class,
+                'sqlsrv' => WorkflowRepositorySQLServer::class,
+            ];
+
+            $driver = DB::connection(
+                (new (config('workflows.stored_workflow_model', StoredWorkflow::class)))->getConnectionName()
+            )->getDriverName();
+
+            return app($drivers[$driver] ?? WorkflowRepositoryMySQL::class);
+        });
     }
 }

tests/Unit/WaterlineServiceProviderTest.php

@@ -68,6 +68,36 @@ public function testExplicitV2EngineSourceBindsUnavailableRepositoryWhenOperator
         $this->assertInstanceOf(UnavailableV2WorkflowRepository::class, $repository);
     }
 
+    public function testPackageRegisterBindsDefaultRepositoryWithoutApplicationProvider(): void
+    {
+        // Simulates a fresh composer install: the package service provider
+        // is loaded via auto-discovery, but the host app has not published
+        // and registered WaterlineApplicationServiceProvider yet. The
+        // Waterline /api/stats and /api/flows/* routes must still resolve.
+        $this->app->offsetUnset(WorkflowRepositoryInterface::class);
+
+        (new WaterlineServiceProvider($this->app))->register();
+
+        $repository = $this->app->make(WorkflowRepositoryInterface::class);
+
+        $this->assertInstanceOf(WorkflowRepositoryInterface::class, $repository);
+    }
+
+    public function testPackageRegisterLeavesHostAppBindingInPlace(): void
+    {
+        // When the host app (or a published WaterlineApplicationServiceProvider
+        // subclass) has already bound WorkflowRepositoryInterface, the
+        // package default must not overwrite it.
+        $custom = $this->createMock(WorkflowRepositoryInterface::class);
+
+        $this->app->offsetUnset(WorkflowRepositoryInterface::class);
+        $this->app->bind(WorkflowRepositoryInterface::class, static fn () => $custom);
+
+        (new WaterlineServiceProvider($this->app))->register();
+
+        $this->assertSame($custom, $this->app->make(WorkflowRepositoryInterface::class));
+    }
+
     public function testBootPassesFloorGuardWhenPinnedToV1EvenIfV2SurfaceIsMissing(): void
     {
         config()->set('waterline.engine_source', 'v1');