diff --git a/src/Composer/Installer/MetapackageInstaller.php b/src/Composer/Installer/MetapackageInstaller.php
index f5a2a43b6..936f72536 100644
--- a/src/Composer/Installer/MetapackageInstaller.php
+++ b/src/Composer/Installer/MetapackageInstaller.php
@@ -26,6 +26,7 @@ use Composer\DependencyResolver\Operation\UninstallOperation;
  */
 class MetapackageInstaller implements InstallerInterface
 {
+    /** @var IOInterface */
     private $io;
 
     public function __construct(IOInterface $io)
diff --git a/src/Composer/Installer/ProjectInstaller.php b/src/Composer/Installer/ProjectInstaller.php
index 5bae889dc..d03e97521 100644
--- a/src/Composer/Installer/ProjectInstaller.php
+++ b/src/Composer/Installer/ProjectInstaller.php
@@ -25,8 +25,11 @@ use Composer\Util\Filesystem;
  */
 class ProjectInstaller implements InstallerInterface
 {
+    /** @var string */
     private $installPath;
+    /** @var DownloadManager */
     private $downloadManager;
+    /** @var Filesystem */
     private $filesystem;
 
     public function __construct($installPath, DownloadManager $dm, Filesystem $fs)
diff --git a/src/Composer/Installer/SuggestedPackagesReporter.php b/src/Composer/Installer/SuggestedPackagesReporter.php
index 0e28e9d50..4db5931d3 100644
--- a/src/Composer/Installer/SuggestedPackagesReporter.php
+++ b/src/Composer/Installer/SuggestedPackagesReporter.php
@@ -29,7 +29,7 @@ class SuggestedPackagesReporter
     const MODE_BY_SUGGESTION = 4;
 
     /**
-     * @var array
+     * @var array<array{source: string, target: string, reason: string}>
      */
     protected $suggestedPackages = array();
 
diff --git a/src/Composer/Package/Version/StabilityFilter.php b/src/Composer/Package/Version/StabilityFilter.php
index d502da257..8eda2033b 100644
--- a/src/Composer/Package/Version/StabilityFilter.php
+++ b/src/Composer/Package/Version/StabilityFilter.php
@@ -30,7 +30,7 @@ class StabilityFilter
      * @param  string   $stability one of 'stable', 'RC', 'beta', 'alpha' or 'dev'
      * @return bool     true if any package name is acceptable
      */
-    public static function isPackageAcceptable(array $acceptableStabilities, array $stabilityFlags, $names, $stability)
+    public static function isPackageAcceptable(array $acceptableStabilities, array $stabilityFlags, array $names, $stability)
     {
         foreach ($names as $name) {
             // allow if package matches the package-specific stability flag
diff --git a/src/Composer/Platform/HhvmDetector.php b/src/Composer/Platform/HhvmDetector.php
index a13559e0d..7bf1beb2c 100644
--- a/src/Composer/Platform/HhvmDetector.php
+++ b/src/Composer/Platform/HhvmDetector.php
@@ -18,11 +18,14 @@ use Symfony\Component\Process\ExecutableFinder;
 
 class HhvmDetector
 {
-    private static $hhvmVersion;
+    /** @var string|false|null */
+    private static $hhvmVersion = null;
+    /** @var ?ExecutableFinder */
     private $executableFinder;
+    /** @var ?ProcessExecutor */
     private $processExecutor;
 
-    public function __construct(ExecutableFinder  $executableFinder = null, ProcessExecutor $processExecutor = null)
+    public function __construct(ExecutableFinder $executableFinder = null, ProcessExecutor $processExecutor = null)
     {
         $this->executableFinder = $executableFinder;
         $this->processExecutor = $processExecutor;
diff --git a/src/Composer/Platform/Runtime.php b/src/Composer/Platform/Runtime.php
index 1cb09e4b1..4e9caff57 100644
--- a/src/Composer/Platform/Runtime.php
+++ b/src/Composer/Platform/Runtime.php
@@ -25,7 +25,7 @@ class Runtime
     }
 
     /**
-     * @param  bool         $constant
+     * @param  string       $constant
      * @param  class-string $class
      * @return mixed
      */
diff --git a/src/Composer/Plugin/PreFileDownloadEvent.php b/src/Composer/Plugin/PreFileDownloadEvent.php
index e4921621e..1c07d5ca6 100644
--- a/src/Composer/Plugin/PreFileDownloadEvent.php
+++ b/src/Composer/Plugin/PreFileDownloadEvent.php
@@ -48,7 +48,7 @@ class PreFileDownloadEvent extends Event
     private $context;
 
     /**
-     * @var array
+     * @var mixed[]
      */
     private $transportOptions = array();
 
diff --git a/src/Composer/Plugin/PrePoolCreateEvent.php b/src/Composer/Plugin/PrePoolCreateEvent.php
index e5e46e708..baa4bc985 100644
--- a/src/Composer/Plugin/PrePoolCreateEvent.php
+++ b/src/Composer/Plugin/PrePoolCreateEvent.php
@@ -16,6 +16,7 @@ use Composer\EventDispatcher\Event;
 use Composer\Repository\RepositoryInterface;
 use Composer\DependencyResolver\Request;
 use Composer\Package\PackageInterface;
+use Composer\Package\BasePackage;
 
 /**
  * The pre command run event.
@@ -33,19 +34,23 @@ class PrePoolCreateEvent extends Event
      */
     private $request;
     /**
-     * @var array
+     * @var int[] array of stability => BasePackage::STABILITY_* value
+     * @phpstan-var array<string, BasePackage::STABILITY_*>
      */
     private $acceptableStabilities;
     /**
-     * @var array
+     * @var int[] array of package name => BasePackage::STABILITY_* value
+     * @phpstan-var array<string, BasePackage::STABILITY_*>
      */
     private $stabilityFlags;
     /**
-     * @var array
+     * @var array[] of package => version => [alias, alias_normalized]
+     * @phpstan-var array<string, array<string, array{alias: string, alias_normalized: string}>>
      */
     private $rootAliases;
     /**
-     * @var array
+     * @var string[]
+     * @phpstan-var array<string, string>
      */
     private $rootReferences;
     /**
@@ -58,8 +63,17 @@ class PrePoolCreateEvent extends Event
     private $unacceptableFixedPackages;
 
     /**
-     * @param string                $name         The event name
+     * @param string                $name                   The event name
      * @param RepositoryInterface[] $repositories
+     * @param int[]                 $acceptableStabilities  array of stability => BasePackage::STABILITY_* value
+     * @param int[]                 $stabilityFlags         array of package name => BasePackage::STABILITY_* value
+     * @param array[]               $rootAliases            array of package => version => [alias, alias_normalized]
+     * @param string[]              $rootReferences
+     *
+     * @phpstan-param array<string, BasePackage::STABILITY_*> $acceptableStabilities
+     * @phpstan-param array<string, BasePackage::STABILITY_*> $stabilityFlags
+     * @phpstan-param array<string, array<string, array{alias: string, alias_normalized: string}>> $rootAliases
+     * @phpstan-param array<string, string> $rootReferences
      */
     public function __construct($name, array $repositories, Request $request, array $acceptableStabilities, array $stabilityFlags, array $rootAliases, array $rootReferences, array $packages, array $unacceptableFixedPackages)
     {
@@ -92,7 +106,8 @@ class PrePoolCreateEvent extends Event
     }
 
     /**
-     * @return array
+     * @return int[] array of stability => BasePackage::STABILITY_* value
+     * @phpstan-return array<string, BasePackage::STABILITY_*>
      */
     public function getAcceptableStabilities()
     {
@@ -100,7 +115,8 @@ class PrePoolCreateEvent extends Event
     }
 
     /**
-     * @return array
+     * @return int[] array of package name => BasePackage::STABILITY_* value
+     * @phpstan-return array<string, BasePackage::STABILITY_*>
      */
     public function getStabilityFlags()
     {
@@ -117,7 +133,8 @@ class PrePoolCreateEvent extends Event
     }
 
     /**
-     * @return array
+     * @return string[]
+     * @phpstan-return array<string, string>
      */
     public function getRootReferences()
     {
diff --git a/src/Composer/Repository/ArtifactRepository.php b/src/Composer/Repository/ArtifactRepository.php
index 0ea1ef71c..02b593a0b 100644
--- a/src/Composer/Repository/ArtifactRepository.php
+++ b/src/Composer/Repository/ArtifactRepository.php
@@ -27,8 +27,11 @@ class ArtifactRepository extends ArrayRepository implements ConfigurableReposito
     /** @var LoaderInterface */
     protected $loader;
 
+    /** @var string */
     protected $lookup;
+    /** @var mixed[] */
     protected $repoConfig;
+    /** @var IOInterface */
     private $io;
 
     public function __construct(array $repoConfig, IOInterface $io)
diff --git a/src/Composer/Repository/ComposerRepository.php b/src/Composer/Repository/ComposerRepository.php
index 0aaf458db..930c4553d 100644
--- a/src/Composer/Repository/ComposerRepository.php
+++ b/src/Composer/Repository/ComposerRepository.php
@@ -44,43 +44,72 @@ use Composer\Util\Url;
  */
 class ComposerRepository extends ArrayRepository implements ConfigurableRepositoryInterface
 {
+    /**
+     * @var mixed[]
+     * @phpstan-var array{url: string, options?: mixed[], type?: 'composer', allow_ssl_downgrade?: bool}
+     */
     private $repoConfig;
+    /** @var mixed[] */
     private $options;
+    /** @var string */
     private $url;
+    /** @var string */
     private $baseUrl;
+    /** @var IOInterface */
     private $io;
     /** @var HttpDownloader */
     private $httpDownloader;
+    /** @var Loop */
     private $loop;
+    /** @var Cache */
     protected $cache;
-    protected $notifyUrl;
-    protected $searchUrl;
-    /** @var string|null a URL containing %package% which can be queried to get providers of a given name */
-    protected $providersApiUrl;
+    /** @var ?string */
+    protected $notifyUrl = null;
+    /** @var ?string */
+    protected $searchUrl = null;
+    /** @var ?string a URL containing %package% which can be queried to get providers of a given name */
+    protected $providersApiUrl = null;
+    /** @var bool */
     protected $hasProviders = false;
-    protected $providersUrl;
-    protected $listUrl;
+    /** @var ?string */
+    protected $providersUrl = null;
+    /** @var ?string */
+    protected $listUrl = null;
     /** @var bool Indicates whether a comprehensive list of packages this repository might provide is expressed in the repository root. **/
     protected $hasAvailablePackageList = false;
-    protected $availablePackages;
-    protected $availablePackagePatterns;
-    protected $lazyProvidersUrl;
+    /** @var ?array<string> */
+    protected $availablePackages = null;
+    /** @var ?array<string> */
+    protected $availablePackagePatterns = null;
+    /** @var ?string */
+    protected $lazyProvidersUrl = null;
+    /** @var ?array<string, array{sha256: string}> */
     protected $providerListing;
+    /** @var ArrayLoader */
     protected $loader;
+    /** @var bool */
     private $allowSslDowngrade = false;
+    /** @var ?EventDispatcher */
     private $eventDispatcher;
+    /** @var ?array<string, array{url: string, preferred: bool}> */
     private $sourceMirrors;
+    /** @var ?array<string, array{url: string, preferred: bool}> */
     private $distMirrors;
+    /** @var bool */
     private $degradedMode = false;
+    /** @var mixed[]|true */
     private $rootData;
-    private $hasPartialPackages;
-    private $partialPackagesByName;
+    /** @var bool */
+    private $hasPartialPackages = false;
+    /** @var ?array<string, PackageInterface> */
+    private $partialPackagesByName = null;
 
     /**
      * TODO v3 should make this private once we can drop PHP 5.3 support
      * @private
      * @var array list of package names which are fresh and can be loaded from the cache directly in case loadPackage is called several times
      *            useful for v2 metadata repositories with lazy providers
+     * @phpstan-var array<string, true>
      */
     public $freshMetadataUrls = array();
 
@@ -89,11 +118,13 @@ class ComposerRepository extends ArrayRepository implements ConfigurableReposito
      * @private
      * @var array list of package names which returned a 404 and should not be re-fetched in case loadPackage is called several times
      *            useful for v2 metadata repositories with lazy providers
+     * @phpstan-var array<string, true>
      */
     public $packagesNotFoundCache = array();
     /**
      * TODO v3 should make this private once we can drop PHP 5.3 support
      * @private
+     * @var VersionParser
      */
     public $versionParser;
 
diff --git a/src/Composer/Repository/CompositeRepository.php b/src/Composer/Repository/CompositeRepository.php
index ac1f2e149..8426364a5 100644
--- a/src/Composer/Repository/CompositeRepository.php
+++ b/src/Composer/Repository/CompositeRepository.php
@@ -23,13 +23,13 @@ class CompositeRepository implements RepositoryInterface
 {
     /**
      * List of repositories
-     * @var array
+     * @var RepositoryInterface[]
      */
     private $repositories;
 
     /**
      * Constructor
-     * @param array $repositories
+     * @param RepositoryInterface[] $repositories
      */
     public function __construct(array $repositories)
     {
@@ -169,8 +169,9 @@ class CompositeRepository implements RepositoryInterface
     public function removePackage(PackageInterface $package)
     {
         foreach ($this->repositories as $repository) {
-            /* @var $repository RepositoryInterface */
-            $repository->removePackage($package);
+            if ($repository instanceof WritableRepositoryInterface) {
+                $repository->removePackage($package);
+            }
         }
     }
 
diff --git a/src/Composer/Repository/FilesystemRepository.php b/src/Composer/Repository/FilesystemRepository.php
index 976eb957d..debdb7a89 100644
--- a/src/Composer/Repository/FilesystemRepository.php
+++ b/src/Composer/Repository/FilesystemRepository.php
@@ -28,9 +28,13 @@ use Composer\Util\Filesystem;
  */
 class FilesystemRepository extends WritableArrayRepository
 {
+    /** @var JsonFile */
     protected $file;
+    /** @var bool */
     private $dumpVersions;
+    /** @var ?RootPackageInterface */
     private $rootPackage;
+    /** @var Filesystem */
     private $filesystem;
 
     /**
diff --git a/src/Composer/Repository/FilterRepository.php b/src/Composer/Repository/FilterRepository.php
index 0582a0f54..8ce7be05f 100644
--- a/src/Composer/Repository/FilterRepository.php
+++ b/src/Composer/Repository/FilterRepository.php
@@ -22,9 +22,13 @@ use Composer\Package\BasePackage;
  */
 class FilterRepository implements RepositoryInterface
 {
-    private $only = array();
-    private $exclude = array();
+    /** @var ?string */
+    private $only = null;
+    /** @var ?string */
+    private $exclude = null;
+    /** @var bool */
     private $canonical = true;
+    /** @var RepositoryInterface */
     private $repo;
 
     public function __construct(RepositoryInterface $repo, array $options)
@@ -174,14 +178,6 @@ class FilterRepository implements RepositoryInterface
         return $result;
     }
 
-    /**
-     * {@inheritdoc}
-     */
-    public function removePackage(PackageInterface $package)
-    {
-        return $this->repo->removePackage($package);
-    }
-
     /**
      * {@inheritdoc}
      */
diff --git a/src/Composer/Repository/PackageRepository.php b/src/Composer/Repository/PackageRepository.php
index de6d31d4d..c5576cf7e 100644
--- a/src/Composer/Repository/PackageRepository.php
+++ b/src/Composer/Repository/PackageRepository.php
@@ -22,6 +22,7 @@ use Composer\Package\Loader\ValidatingArrayLoader;
  */
 class PackageRepository extends ArrayRepository
 {
+    /** @var mixed[] */
     private $config;
 
     /**
diff --git a/src/Composer/Repository/PathRepository.php b/src/Composer/Repository/PathRepository.php
index c1fc632da..7232e0368 100644
--- a/src/Composer/Repository/PathRepository.php
+++ b/src/Composer/Repository/PathRepository.php
@@ -77,7 +77,8 @@ class PathRepository extends ArrayRepository implements ConfigurableRepositoryIn
     private $url;
 
     /**
-     * @var array
+     * @var mixed[]
+     * @phpstan-var array{url: string, options?: array{symlink?: bool, relative?: bool, versions?: array<string, string>}}
      */
     private $repoConfig;
 
@@ -87,7 +88,7 @@ class PathRepository extends ArrayRepository implements ConfigurableRepositoryIn
     private $process;
 
     /**
-     * @var array
+     * @var array{symlink?: bool, relative?: bool, versions?: array<string, string>}
      */
     private $options;
 
diff --git a/src/Composer/Repository/PlatformRepository.php b/src/Composer/Repository/PlatformRepository.php
index 095c86a8a..5cd1ae27c 100644
--- a/src/Composer/Repository/PlatformRepository.php
+++ b/src/Composer/Repository/PlatformRepository.php
@@ -46,13 +46,15 @@ class PlatformRepository extends ArrayRepository
     /**
      * Defines overrides so that the platform can be mocked
      *
-     * Should be an array of package name => version number mappings
+     * Keyed by package name (lowercased)
      *
-     * @var array
+     * @var array<string, array{name: string, version: string}>
      */
     private $overrides = array();
 
+    /** @var Runtime */
     private $runtime;
+    /** @var HhvmDetector */
     private $hhvmDetector;
 
     public function __construct(array $packages = array(), array $overrides = array(), Runtime $runtime = null, HhvmDetector $hhvmDetector = null)
diff --git a/src/Composer/Repository/RepositorySet.php b/src/Composer/Repository/RepositorySet.php
index ae7e2cba8..d87a334b3 100644
--- a/src/Composer/Repository/RepositorySet.php
+++ b/src/Composer/Repository/RepositorySet.php
@@ -67,6 +67,10 @@ class RepositorySet
      */
     private $stabilityFlags;
 
+    /**
+     * @var ConstraintInterface[]
+     * @phpstan-var array<string, ConstraintInterface>
+     */
     private $rootRequires;
 
     /** @var bool */
@@ -86,6 +90,8 @@ class RepositorySet
      * @phpstan-param list<array{package: string, version: string, alias: string, alias_normalized: string}> $rootAliases
      * @param string[] $rootReferences an array of package name => source reference
      * @phpstan-param array<string, string> $rootReferences
+     * @param ConstraintInterface[] $rootRequires an array of package name => constraint from the root package
+     * @phpstan-param array<string, ConstraintInterface> $rootRequires
      */
     public function __construct($minimumStability = 'stable', array $stabilityFlags = array(), array $rootAliases = array(), array $rootReferences = array(), array $rootRequires = array())
     {
@@ -112,6 +118,10 @@ class RepositorySet
         $this->allowInstalledRepositories = $allow;
     }
 
+    /**
+     * @return ConstraintInterface[] an array of package name => constraint from the root package, platform requirements excluded
+     * @phpstan-return array<string, ConstraintInterface>
+     */
     public function getRootRequires()
     {
         return $this->rootRequires;
@@ -193,6 +203,12 @@ class RepositorySet
         return $result;
     }
 
+    /**
+     * @param  string   $packageName
+     *
+     * @return array[] an array with the provider name as key and value of array('name' => '...', 'description' => '...', 'type' => '...')
+     * @phpstan-return array<string, array{name: string, description: string, type: string}>
+     */
     public function getProviders($packageName)
     {
         $providers = array();
@@ -205,6 +221,13 @@ class RepositorySet
         return $providers;
     }
 
+    /**
+     * Check for each given package name whether it would be accepted by this RepositorySet in the given $stability
+     *
+     * @param  string[] $names
+     * @param  string   $stability one of 'stable', 'RC', 'beta', 'alpha' or 'dev'
+     * @return bool
+     */
     public function isPackageAcceptable($names, $stability)
     {
         return StabilityFilter::isPackageAcceptable($this->acceptableStabilities, $this->stabilityFlags, $names, $stability);
diff --git a/src/Composer/Repository/Vcs/BitbucketDriver.php b/src/Composer/Repository/Vcs/BitbucketDriver.php
index 96b4c3298..8bd47a7a2 100644
--- a/src/Composer/Repository/Vcs/BitbucketDriver.php
+++ b/src/Composer/Repository/Vcs/BitbucketDriver.php
@@ -20,16 +20,27 @@ use Composer\Util\Http\Response;
 
 abstract class BitbucketDriver extends VcsDriver
 {
+    /** @var string */
     protected $owner;
+    /** @var string */
     protected $repository;
-    protected $hasIssues;
+    /** @var bool */
+    protected $hasIssues = false;
+    /** @var ?string */
     protected $rootIdentifier;
+    /** @var array<string, string> Map of tag name to identifier */
     protected $tags;
+    /** @var array<string, string> Map of branch name to identifier */
     protected $branches;
+    /** @var string */
     protected $branchesUrl = '';
+    /** @var string */
     protected $tagsUrl = '';
+    /** @var string */
     protected $homeUrl = '';
+    /** @var string */
     protected $website = '';
+    /** @var string */
     protected $cloneHttpsUrl = '';
 
     /**
diff --git a/src/Composer/Repository/Vcs/FossilDriver.php b/src/Composer/Repository/Vcs/FossilDriver.php
index 8f73ffb5e..c4c468f40 100644
--- a/src/Composer/Repository/Vcs/FossilDriver.php
+++ b/src/Composer/Repository/Vcs/FossilDriver.php
@@ -23,10 +23,15 @@ use Composer\IO\IOInterface;
  */
 class FossilDriver extends VcsDriver
 {
+    /** @var array<string, string> Map of tag name to identifier */
     protected $tags;
+    /** @var array<string, string> Map of branch name to identifier */
     protected $branches;
-    protected $rootIdentifier;
-    protected $repoFile;
+    /** @var ?string */
+    protected $rootIdentifier = null;
+    /** @var ?string */
+    protected $repoFile = null;
+    /** @var string */
     protected $checkoutDir;
 
     /**
diff --git a/src/Composer/Repository/Vcs/GitDriver.php b/src/Composer/Repository/Vcs/GitDriver.php
index ea7803631..4fef3f702 100644
--- a/src/Composer/Repository/Vcs/GitDriver.php
+++ b/src/Composer/Repository/Vcs/GitDriver.php
@@ -25,9 +25,13 @@ use Composer\Config;
  */
 class GitDriver extends VcsDriver
 {
+    /** @var array<string, string> Map of tag name to identifier */
     protected $tags;
+    /** @var array<string, string> Map of branch name to identifier */
     protected $branches;
+    /** @var string */
     protected $rootIdentifier;
+    /** @var string */
     protected $repoDir;
 
     /**
diff --git a/src/Composer/Repository/Vcs/GitHubDriver.php b/src/Composer/Repository/Vcs/GitHubDriver.php
index b312edeac..e7d84a078 100644
--- a/src/Composer/Repository/Vcs/GitHubDriver.php
+++ b/src/Composer/Repository/Vcs/GitHubDriver.php
@@ -25,15 +25,25 @@ use Composer\Util\Http\Response;
  */
 class GitHubDriver extends VcsDriver
 {
+    /** @var string */
     protected $owner;
+    /** @var string */
     protected $repository;
+    /** @var array<string, string> Map of tag name to identifier */
     protected $tags;
+    /** @var array<string, string> Map of branch name to identifier */
     protected $branches;
+    /** @var string */
     protected $rootIdentifier;
+    /** @var mixed[] */
     protected $repoData;
-    protected $hasIssues;
+    /** @var bool */
+    protected $hasIssues = false;
+    /** @var bool */
     protected $isPrivate = false;
+    /** @var bool */
     private $isArchived = false;
+    /** @var array<int, array{type: string, url: string}>|false|null */
     private $fundingInfo;
 
     /**
diff --git a/src/Composer/Repository/Vcs/GitLabDriver.php b/src/Composer/Repository/Vcs/GitLabDriver.php
index 2bc0cf61c..8e9d9059d 100644
--- a/src/Composer/Repository/Vcs/GitLabDriver.php
+++ b/src/Composer/Repository/Vcs/GitLabDriver.php
@@ -29,28 +29,30 @@ use Composer\Util\Http\Response;
  */
 class GitLabDriver extends VcsDriver
 {
+    /**
+     * @var string
+     * @phpstan-var 'https'|'http'
+     */
     private $scheme;
+    /** @var string */
     private $namespace;
+    /** @var string */
     private $repository;
 
     /**
-     * @var array Project data returned by GitLab API
+     * @var mixed[] Project data returned by GitLab API
      */
     private $project;
 
     /**
-     * @var array Keeps commits returned by GitLab API
+     * @var array<string, mixed[]> Keeps commits returned by GitLab API
      */
     private $commits = array();
 
-    /**
-     * @var array List of tag => reference
-     */
+    /** @var array<string, string> Map of tag name to identifier */
     private $tags;
 
-    /**
-     * @var array List of branch => reference
-     */
+    /** @var array<string, string> Map of branch name to identifier */
     private $branches;
 
     /**
diff --git a/src/Composer/Repository/Vcs/HgDriver.php b/src/Composer/Repository/Vcs/HgDriver.php
index 9b6b68803..56e35ea30 100644
--- a/src/Composer/Repository/Vcs/HgDriver.php
+++ b/src/Composer/Repository/Vcs/HgDriver.php
@@ -24,9 +24,13 @@ use Composer\IO\IOInterface;
  */
 class HgDriver extends VcsDriver
 {
+    /** @var array<string, string> Map of tag name to identifier */
     protected $tags;
+    /** @var array<string, string> Map of branch name to identifier */
     protected $branches;
+    /** @var string */
     protected $rootIdentifier;
+    /** @var string */
     protected $repoDir;
 
     /**
diff --git a/src/Composer/Repository/Vcs/PerforceDriver.php b/src/Composer/Repository/Vcs/PerforceDriver.php
index 861b67038..76249fd54 100644
--- a/src/Composer/Repository/Vcs/PerforceDriver.php
+++ b/src/Composer/Repository/Vcs/PerforceDriver.php
@@ -23,7 +23,9 @@ use Composer\Util\Perforce;
  */
 class PerforceDriver extends VcsDriver
 {
+    /** @var string */
     protected $depot;
+    /** @var string */
     protected $branch;
     /** @var ?Perforce */
     protected $perforce = null;
diff --git a/src/Composer/Repository/Vcs/SvnDriver.php b/src/Composer/Repository/Vcs/SvnDriver.php
index ab3f95f16..9ea596115 100644
--- a/src/Composer/Repository/Vcs/SvnDriver.php
+++ b/src/Composer/Repository/Vcs/SvnDriver.php
@@ -28,15 +28,24 @@ use Composer\Downloader\TransportException;
  */
 class SvnDriver extends VcsDriver
 {
+    /** @var string */
     protected $baseUrl;
+    /** @var array<string, string> Map of tag name to identifier */
     protected $tags;
+    /** @var array<string, string> Map of branch name to identifier */
     protected $branches;
+    /** @var ?string */
     protected $rootIdentifier;
 
+    /** @var string|false */
     protected $trunkPath = 'trunk';
+    /** @var string */
     protected $branchesPath = 'branches';
+    /** @var string */
     protected $tagsPath = 'tags';
+    /** @var string */
     protected $packagePath = '';
+    /** @var bool */
     protected $cacheCredentials = true;
 
     /**
diff --git a/src/Composer/Repository/Vcs/VcsDriver.php b/src/Composer/Repository/Vcs/VcsDriver.php
index ae86e44a7..7e287e33c 100644
--- a/src/Composer/Repository/Vcs/VcsDriver.php
+++ b/src/Composer/Repository/Vcs/VcsDriver.php
@@ -33,7 +33,7 @@ abstract class VcsDriver implements VcsDriverInterface
     protected $url;
     /** @var string */
     protected $originUrl;
-    /** @var array */
+    /** @var array<string, mixed> */
     protected $repoConfig;
     /** @var IOInterface */
     protected $io;
@@ -43,7 +43,7 @@ abstract class VcsDriver implements VcsDriverInterface
     protected $process;
     /** @var HttpDownloader */
     protected $httpDownloader;
-    /** @var array */
+    /** @var array<string, mixed> */
     protected $infoCache = array();
     /** @var ?Cache */
     protected $cache;
diff --git a/src/Composer/Repository/VcsRepository.php b/src/Composer/Repository/VcsRepository.php
index 2456baaea..2740bb603 100644
--- a/src/Composer/Repository/VcsRepository.php
+++ b/src/Composer/Repository/VcsRepository.php
@@ -32,25 +32,41 @@ use Composer\Config;
  */
 class VcsRepository extends ArrayRepository implements ConfigurableRepositoryInterface
 {
+    /** @var string */
     protected $url;
+    /** @var ?string */
     protected $packageName;
+    /** @var bool */
     protected $isVerbose;
+    /** @var bool */
     protected $isVeryVerbose;
+    /** @var IOInterface */
     protected $io;
+    /** @var Config */
     protected $config;
+    /** @var VersionParser */
     protected $versionParser;
+    /** @var string */
     protected $type;
+    /** @var ?LoaderInterface */
     protected $loader;
+    /** @var array<string, mixed> */
     protected $repoConfig;
+    /** @var HttpDownloader */
     protected $httpDownloader;
+    /** @var ProcessExecutor */
     protected $processExecutor;
+    /** @var bool */
     protected $branchErrorOccurred = false;
+    /** @var array<string, class-string> */
     private $drivers;
     /** @var ?VcsDriverInterface */
     private $driver;
     /** @var ?VersionCacheInterface */
     private $versionCache;
+    /** @var string[] */
     private $emptyReferences = array();
+    /** @var array<'tags'|'branches', array<string, \Throwable>> */
     private $versionTransportExceptions = array();
 
     public function __construct(array $repoConfig, IOInterface $io, Config $config, HttpDownloader $httpDownloader, EventDispatcher $dispatcher = null, ProcessExecutor $process = null, array $drivers = null, VersionCacheInterface $versionCache = null)