Load plugins which modify install path early

doc/articles/plugins.md

@@ -323,6 +323,15 @@ hint to Composer that the plugin should be installed on its own before proceedin
 the rest of the package downloads. This slightly slows down the overall installation
 process however, so do not use it in plugins which do not absolutely require it.
 
+### plugin-modifies-install-path
+
+Some special plugins modify the install path of packages.
+
+As of Composer 2.2.9, you can specify `{"extra": {"plugin-modifies-install-path": true}}`
+in your composer.json to hint to Composer that the plugin should be activated as soon
+as possible to prevent any bad side-effects from Composer assuming packages are installed
+in another location than they actually are.
+
 ## Plugin Autoloading
 
 Due to plugins being loaded by Composer at runtime, and to ensure that plugins which

src/Composer/Plugin/PluginManager.php

@@ -477,7 +477,18 @@ public function uninstallPlugin(PluginInterface $plugin)
     private function loadRepository(RepositoryInterface $repo, $isGlobalRepo)
     {
         $packages = $repo->getPackages();
-        $sortedPackages = PackageSorter::sortPackages($packages);
+
+        $weights = array();
+        foreach ($packages as $package) {
+            if ($package->getType() === 'composer-plugin') {
+                $extra = $package->getExtra();
+                if ($package->getName() === 'composer/installers' || (isset($extra['plugin-modifies-install-path']) && $extra['plugin-modifies-install-path'] === true)) {
+                    $weights[$package->getName()] = -10000;
+                }
+            }
+        }
+
+        $sortedPackages = PackageSorter::sortPackages($packages, $weights);
         foreach ($sortedPackages as $package) {
             if (!($package instanceof CompletePackage)) {
                 continue;

src/Composer/Util/PackageSorter.php

@@ -23,9 +23,10 @@ class PackageSorter
      * Packages of equal weight are sorted alphabetically
      *
      * @param  PackageInterface[] $packages
+     * @param  array<string, int> $weights Pre-set weights for some packages to give them more (negative number) or less (positive) weight offsets
      * @return PackageInterface[] sorted array
      */
-    public static function sortPackages(array $packages)
+    public static function sortPackages(array $packages, array $weights = array())
     {
         $usageList = array();
 
@@ -41,7 +42,7 @@ public static function sortPackages(array $packages)
         }
         $computing = array();
         $computed = array();
-        $computeImportance = function ($name) use (&$computeImportance, &$computing, &$computed, $usageList) {
+        $computeImportance = function ($name) use (&$computeImportance, &$computing, &$computed, $usageList, $weights) {
             // reusing computed importance
             if (isset($computed[$name])) {
                 return $computed[$name];
@@ -53,7 +54,7 @@ public static function sortPackages(array $packages)
             }
 
             $computing[$name] = true;
-            $weight = 0;
+            $weight = isset($weights[$name]) ? $weights[$name] : 0;
 
             if (isset($usageList[$name])) {
                 foreach ($usageList[$name] as $user) {

tests/Composer/Test/Util/PackageSorterTest.php

@@ -127,6 +127,23 @@ public function sortingOrdersDependenciesHigherThanPackageDataProvider()
                     'foo/baz',
                 ),
             ),
+            'pre-weighted packages bumped to top incl their deps' => array(
+                array(
+                    $this->createPackage('foo/bar', array('foo/dep')),
+                    $this->createPackage('foo/bar2', array('foo/dep2')),
+                    $this->createPackage('foo/dep', array()),
+                    $this->createPackage('foo/dep2', array()),
+                ),
+                array(
+                    'foo/dep',
+                    'foo/bar',
+                    'foo/dep2',
+                    'foo/bar2',
+                ),
+                array(
+                    'foo/bar' => -1000
+                )
+            ),
         );
     }
 
@@ -135,10 +152,11 @@ public function sortingOrdersDependenciesHigherThanPackageDataProvider()
      *
      * @param Package[] $packages
      * @param string[]  $expectedOrderedList
+     * @param array<string, int> $weights
      */
-    public function testSortingOrdersDependenciesHigherThanPackage($packages, $expectedOrderedList)
+    public function testSortingOrdersDependenciesHigherThanPackage($packages, $expectedOrderedList, $weights = array())
     {
-        $sortedPackages = PackageSorter::sortPackages($packages);
+        $sortedPackages = PackageSorter::sortPackages($packages, $weights);
         $sortedPackageNames = array_map(function ($package) {
             return $package->getName();
         }, $sortedPackages);