Add yarn installer

Author: mariusbuescher

README.md

@@ -6,10 +6,10 @@ PHP projects mostly are Web-Applications. Many Web-Applications also need a fron
 modern Web-Development there often a whole build-chain connected to the frontend, so you can compile e.g. your scss, build
 your JavaScript with webpack and optimize your images.
 
-This plugin provides a way to automatically download the right version of node.js and npm as a package. The binaries are
-linked to the bin-directory specified in your composer.json.
+This plugin provides a way to automatically download and installthe right version of node.js, npm and yarn. The binaries
+are linked to the bin-directory specified in your composer.json.
 
-After that your can use node and npm in your scripts.
+After that your can use node, npm and yarn in your composer-scripts.
 
 ## Setup
 
@@ -34,7 +34,8 @@ Example composer.json
     "extra": {
         "mariusbuescher": {
             "node-composer": {
-                "node-version": "4.8.3"
+                "node-version": "4.8.3",
+                "yarn-version": "0.22.0"
             }
         }
     }

src/Installer/YarnInstaller.php

@@ -0,0 +1,123 @@
+<?php
+
+namespace MariusBuescher\NodeComposer\Installer;
+
+use Composer\IO\IOInterface;
+use MariusBuescher\NodeComposer\InstallerInterface;
+use MariusBuescher\NodeComposer\NodeContext;
+
+class YarnInstaller implements InstallerInterface
+{
+    /**
+     * @var IOInterface
+     */
+    private $io;
+
+    /**
+     * @var NodeContext
+     */
+    private $context;
+
+    /**
+     * NodeDownloader constructor.
+     * @param IOInterface $io
+     * @param NodeContext $context
+     */
+    public function __construct(
+        IOInterface $io,
+        NodeContext $context
+    ) {
+        $this->io = $io;
+        $this->context = $context;
+    }
+
+    /**
+     * @param string $version
+     * @throws \InvalidArgumentException
+     * @return bool
+     */
+    public function install($version)
+    {
+        if (!is_string($version)) {
+            throw new \InvalidArgumentException(
+                sprintf('Version must be a string, %s given'), gettype($version)
+            );
+        }
+
+        $output = $return = null;
+
+        exec(
+            $this->context->getBinDir() . DIRECTORY_SEPARATOR . 'npm install --global yarn@' . $version,
+            $output,
+            $return
+        );
+
+        if ($return !== 0) {
+            throw new \RuntimeException('Could not install yarn');
+        }
+
+        $sourceDir = $this->getNpmBinaryPath();
+
+        $this->linkExecutables($sourceDir, $this->context->getBinDir());
+
+        return true;
+    }
+
+    public function isInstalled()
+    {
+        $output = array();
+        $return = null;
+
+        $nodeExecutable = $this->context->getBinDir() . DIRECTORY_SEPARATOR . 'yarn';
+
+        exec("$nodeExecutable --version", $output, $return);
+
+        if ($return === 0) {
+            return $output[0];
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * @param string $sourceDir
+     * @param string $targetDir
+     */
+    private function linkExecutables($sourceDir, $targetDir)
+    {
+        $yarnPath = realpath($sourceDir . DIRECTORY_SEPARATOR . 'yarn');
+        $yarnLink = $targetDir . DIRECTORY_SEPARATOR . 'yarn';
+
+        if (realpath($yarnLink)) {
+            unlink($yarnLink);
+        }
+
+        symlink($yarnPath, $yarnLink);
+
+        $yarnpkgPath = realpath($sourceDir . DIRECTORY_SEPARATOR . 'yarnpkg');
+        $yarnpkgLink = $targetDir . DIRECTORY_SEPARATOR . 'yarnpkg';
+
+        if (realpath($yarnpkgLink)) {
+            unlink($yarnpkgLink);
+        }
+
+        symlink($yarnpkgPath, $yarnpkgLink);
+    }
+
+    /**
+     * @return string
+     */
+    private function getNpmBinaryPath()
+    {
+        $output = array();
+        $return = null;
+
+        exec($this->context->getBinDir() . DIRECTORY_SEPARATOR . 'npm -g bin', $output, $return);
+
+        if ($return !== 0) {
+            throw new \RuntimeException('npm must be installed');
+        }
+
+        return $output[0];
+    }
+}

src/NodeComposerPlugin.php

@@ -12,6 +12,7 @@
 use Composer\Util\RemoteFilesystem;
 use MariusBuescher\NodeComposer\Exception\NodeComposerConfigException;
 use MariusBuescher\NodeComposer\Installer\NodeInstaller;
+use MariusBuescher\NodeComposer\Installer\YarnInstaller;
 
 class NodeComposerPlugin implements PluginInterface, EventSubscriberInterface
 {
@@ -69,13 +70,29 @@ public function onPostUpdate(Event $event)
             $context
         );
 
-        $installedVersion = $nodeInstaller->isInstalled();
+        $installedNodeVersion = $nodeInstaller->isInstalled();
 
         if (
-            $installedVersion === false ||
-            strpos($installedVersion, 'v' . $this->config->getNodeVersion()) === false
+            $installedNodeVersion === false ||
+            strpos($installedNodeVersion, 'v' . $this->config->getNodeVersion()) === false
         ) {
             $nodeInstaller->install($this->config->getNodeVersion());
         }
+
+        if ($this->config->getYarnVersion() !== null) {
+            $yarnInstaller = new YarnInstaller(
+                $this->io,
+                $context
+            );
+
+            $installedYarnVersion = $yarnInstaller->isInstalled();
+
+            if (
+                $installedYarnVersion === false ||
+                strpos($installedYarnVersion, $this->config->getYarnVersion()) === false
+            ) {
+                $yarnInstaller->install($this->config->getYarnVersion());
+            }
+        }
     }
 }