Psalm level 1

.gitattributes

@@ -8,6 +8,7 @@
 .travis.yml export-ignore
 phpunit.xml.dist export-ignore
 psalm.xml export-ignore
+stubs/ export-ignore
 tests/ export-ignore
 
 # Other dotfiles

psalm.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <psalm
-    errorLevel="2"
+    errorLevel="1"
     resolveFromConfigFile="true"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="https://getpsalm.org/schema/config"
@@ -12,4 +12,8 @@
             <directory name="vendor" />
         </ignoreFiles>
     </projectFiles>
+
+    <stubs>
+        <file name="stubs/composer.phpstub" />
+    </stubs>
 </psalm>

src/ComposerInstaller/CmsInstaller.php

@@ -42,14 +42,14 @@ public function getInstallPath(PackageInterface $package): string
         }
 
         // use path from configuration, otherwise fall back to default
-        if (isset($extra['kirby-cms-path'])) {
+        if (isset($extra['kirby-cms-path']) === true) {
             $path = $extra['kirby-cms-path'];
         } else {
             $path = 'kirby';
         }
 
         // if explicitly set to something invalid (e.g. `false`), install to vendor dir
-        if (!is_string($path)) {
+        if (is_string($path) !== true) {
             return parent::getInstallPath($package);
         }
 

src/ComposerInstaller/Installer.php

@@ -94,9 +94,10 @@ protected function postInstall(PackageInterface $package)
     {
         // remove the package's `vendor` directory to avoid duplicated autoloader and vendor code
         $packageVendorDir = $this->getInstallPath($package) . '/vendor';
-        if (is_dir($packageVendorDir)) {
+        if (is_dir($packageVendorDir) === true) {
             $success = $this->filesystem->removeDirectory($packageVendorDir);
-            if (!$success) {
+
+            if ($success !== true) {
                 throw new RuntimeException('Could not completely delete ' . $packageVendorDir . ', aborting.'); // @codeCoverageIgnore
             }
         }

src/ComposerInstaller/PluginInstaller.php

@@ -3,6 +3,7 @@
 namespace Kirby\ComposerInstaller;
 
 use Composer\Package\PackageInterface;
+use InvalidArgumentException;
 
 /**
  * @package   Kirby Composer Installer
@@ -47,12 +48,20 @@ public function getInstallPath(PackageInterface $package): string
         // use base path from configuration, otherwise fall back to default
         $basePath = $extra['kirby-plugin-path'] ?? 'site/plugins';
 
+        if (is_string($basePath) !== true) {
+            throw new InvalidArgumentException('Invalid "kirby-plugin-path" option');
+        }
+
         // determine the plugin name from its package name;
         // can be overridden in the plugin's `composer.json`
         $prettyName = $package->getPrettyName();
         $pluginExtra = $package->getExtra();
-        if (!empty($pluginExtra['installer-name'])) {
+        if (empty($pluginExtra['installer-name']) === false) {
             $name = $pluginExtra['installer-name'];
+
+            if (is_string($name) !== true) {
+                throw new InvalidArgumentException('Invalid "installer-name" option in plugin ' . $prettyName);
+            }
         } elseif (strpos($prettyName, '/') !== false) {
             // use name after the slash
             $name = explode('/', $prettyName)[1];

stubs/composer.phpstub

@@ -0,0 +1,35 @@
+<?php
+
+namespace Composer
+{
+    class Config
+    {
+        /**
+         * Returns a setting
+         *
+         * @template T as string
+         * @param T $key
+         * @param int $flags
+         * @psalm-return (T is 'vendor-dir' ? string|null : mixed)
+         */
+        public function get($key, $flags = 0)
+        { 
+        }
+    }
+}
+
+namespace Composer\Installer
+{
+    class LibraryInstaller
+    {
+        /**
+         * @var \Composer\Composer
+         */
+        protected $composer;
+
+        /**
+         * @var \Composer\Util\Filesystem
+         */
+        protected $filesystem;
+    }
+}

tests/ComposerInstaller/PluginInstallerTest.php

@@ -70,6 +70,35 @@ public function testGetInstallPathCustomPaths()
         $this->assertEquals('data/plugins/another-name', $this->installer->getInstallPath($package));
     }
 
+    public function testGetInstallPathInvalidPluginPath()
+    {
+        $this->expectException('InvalidArgumentException');
+        $this->expectExceptionMessage('Invalid "kirby-plugin-path" option');
+
+        $this->initRootPackage()->setExtra([
+            'kirby-plugin-path' => false
+        ]);
+
+        $package = $this->pluginPackageFactory(self::SUPPORTED);
+        $this->installer->getInstallPath($package);
+    }
+
+    public function testGetInstallPathInvalidInstallerName()
+    {
+        $this->expectException('InvalidArgumentException');
+        $this->expectExceptionMessage('Invalid "installer-name" option in plugin superwoman/superplugin');
+
+        $this->initRootPackage()->setExtra([
+            'kirby-plugin-path' => 'data/plugins'
+        ]);
+
+        $package = $this->pluginPackageFactory(self::SUPPORTED);
+        $package->setExtra([
+            'installer-name' => true
+        ]);
+        $this->installer->getInstallPath($package);
+    }
+
     public function testInstallNoSupport()
     {
         $package = $this->pluginPackageFactory(self::VENDOR_DIR);