feat(core): add Composer util (#519)

src/Composer.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Core;
+
+use function Tempest\Support\arr;
+use Tempest\Support\PathHelper;
+
+final readonly class Composer
+{
+    /** @var array<ComposerNamespace> */
+    public array $namespaces;
+
+    public ?ComposerNamespace $mainNamespace;
+
+    public array $composer;
+
+    public function __construct(
+        string $root,
+    ) {
+        $composerFilePath = PathHelper::make($root, 'composer.json');
+
+        $this->composer = $this->loadComposerFile($composerFilePath);
+        $this->namespaces = arr($this->composer)
+            ->get('autoload.psr-4', default: arr())
+            ->map(fn (string $path, string $namespace) => new ComposerNamespace($namespace, $path))
+            ->values()
+            ->toArray();
+
+        foreach ($this->namespaces as $namespace) {
+            if (str_starts_with($namespace->path, 'app/') || str_starts_with($namespace->path, 'src/')) {
+                $this->mainNamespace = $namespace;
+
+                break;
+            }
+        }
+
+        if (! isset($this->mainNamespace) && count($this->namespaces)) {
+            $this->mainNamespace = $this->namespaces[0];
+        }
+
+        if (! isset($this->mainNamespace)) {
+            throw new KernelException("Tempest requires at least one PSR-4 namespace to be defined in composer.json.");
+        }
+    }
+
+    private function loadComposerFile(string $path): array
+    {
+        if (! file_exists($path)) {
+            throw new KernelException("Could not locate composer.json.");
+        }
+
+        return json_decode(file_get_contents($path), associative: true);
+    }
+}

src/ComposerNamespace.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Core;
+
+final readonly class ComposerNamespace
+{
+    public function __construct(
+        public string $namespace,
+        public string $path,
+    ) {
+    }
+}

src/Kernel.php

@@ -36,6 +36,7 @@ public function __construct(
             ->setDiscoveryCache($discoveryCache)
             ->registerShutdownFunction()
             ->registerKernel()
+            ->loadComposer()
             ->loadDiscoveryLocations()
             ->loadConfig()
             ->loadExceptionHandler()
@@ -62,6 +63,13 @@ private function createContainer(): Container
         return $container;
     }
 
+    private function loadComposer(): self
+    {
+        $this->container->singleton(Composer::class, new Composer($this->root));
+
+        return $this;
+    }
+
     private function loadEnv(): self
     {
         $dotenv = Dotenv::createUnsafeImmutable($this->root);

src/Kernel/LoadDiscoveryLocations.php

@@ -4,6 +4,7 @@
 
 namespace Tempest\Core\Kernel;
 
+use Tempest\Core\Composer;
 use Tempest\Core\DiscoveryException;
 use Tempest\Core\DiscoveryLocation;
 use Tempest\Core\Kernel;
@@ -14,6 +15,7 @@
 {
     public function __construct(
         private Kernel $kernel,
+        private Composer $composer,
     ) {
     }
 
@@ -64,15 +66,12 @@ private function discoverCorePackages(): array
      */
     private function discoverAppNamespaces(): array
     {
-        $composer = $this->loadJsonFile(PathHelper::make($this->kernel->root, 'composer.json'));
-        $namespaceMap = $composer['autoload']['psr-4'] ?? [];
-
         $discoveredLocations = [];
 
-        foreach ($namespaceMap as $namespace => $path) {
-            $path = PathHelper::make($this->kernel->root, $path);
+        foreach ($this->composer->namespaces as $namespace) {
+            $path = PathHelper::make($this->kernel->root, $namespace->path);
 
-            $discoveredLocations[] = new DiscoveryLocation($namespace, $path);
+            $discoveredLocations[] = new DiscoveryLocation($namespace->namespace, $path);
         }
 
         return $discoveredLocations;