Split out patch resolution into Composer Capabilities

src/Capability/BaseResolverProvider.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace cweagans\Composer\Capability;
+
+use Composer\Composer;
+use Composer\IO\IOInterface;
+use Composer\Plugin\Capability\Capability;
+use Composer\Plugin\PluginInterface;
+
+abstract class BaseResolverProvider implements Capability, ResolverProvider
+{
+    /**
+     * @var Composer
+     */
+    protected $composer;
+
+    /**
+     * @var IOInterface
+     */
+    protected $io;
+
+    /**
+     * @var PluginInterface
+     */
+    protected $plugin;
+
+    /**
+     * BaseResolverProvider constructor.
+     *
+     * Stores values passed by the plugin manager for later use.
+     *
+     * @param array $args
+     *   An array of args passed by the plugin manager.
+     */
+    public function __construct($args)
+    {
+        $this->composer = $args['composer'];
+        $this->io = $args['io'];
+        $this->plugin = $args['plugin'];
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    abstract public function getResolvers();
+}

src/Capability/CoreResolverProvider.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace cweagans\Composer\Capability;
+
+use cweagans\Composer\Resolvers\DependencyPatches;
+use cweagans\Composer\Resolvers\PatchesFile;
+use cweagans\Composer\Resolvers\RootComposer;
+
+class CoreResolverProvider extends BaseResolverProvider
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function getResolvers()
+    {
+        return [
+            new RootComposer($this->composer, $this->io),
+            new PatchesFile($this->composer, $this->io),
+            new DependencyPatches($this->composer, $this->io),
+        ];
+    }
+}

src/Capability/ResolverProvider.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace cweagans\Composer\Capability;
+
+use Composer\Plugin\Capability\Capability;
+
+/**
+ * Resolver provider interface.
+ *
+ * This capability will receive an array with 'composer' and 'io' keys as
+ * constructor arguments. It also contains a 'plugin' key containing the
+ * plugin instance that declared the capability.
+ */
+interface ResolverProvider extends Capability
+{
+    /**
+     * Retrieves an array of PatchResolvers.
+     *
+     * @return \cweagans\Composer\Resolvers\ResolverBase[]
+     */
+    public function getResolvers();
+}