Add native return types where possible

.php-cs-fixer.php

@@ -71,7 +71,6 @@
         'random_api_migration' => true,
         'ternary_to_null_coalescing' => true,
         //'declare_strict_types' => true,
-        //'void_return' => true,
     ])
     ->setUsingCache(true)
     ->setRiskyAllowed(true)

phpstan/config.neon

@@ -31,15 +31,11 @@ parameters:
         - '~^Undefined variable: \$vendorDir$~'
         - '~^Undefined variable: \$baseDir$~'
 
-        # variable defined in eval
-        - '~^Undefined variable: \$res$~'
-
         # we don't have different constructors for parent/child
         - '~^Unsafe usage of new static\(\)\.$~'
 
         # Ignore some irrelevant errors in test files
-        - '~Method Composer\\Test\\[^:]+::(setUp(BeforeClass)?|tearDown(AfterClass)?|test[^(]+)\(\) has no return type specified.~'
-        - '~Method Composer\\Test\\[^:]+::(data\w+|provide\w+|\w+?Provider)\(\) has no return type specified.~'
+        - '~Method Composer\\Test\\[^:]+::(data\w+|provide\w+|\w+?Provider)\(\) (has no return type specified.|return type has no value type specified in iterable type array.)~'
 
         # PHPUnit assertions as instance methods
         - '~Dynamic call to static method PHPUnit\\Framework\\Assert::\w+\(\)~'

src/Composer/Autoload/AutoloadGenerator.php

@@ -290,7 +290,7 @@ public function dump(Config $config, InstalledRepositoryInterface $localRepo, Ro
         $mainAutoload = $rootPackage->getAutoload();
         if ($rootPackage->getTargetDir() && !empty($mainAutoload['psr-0'])) {
             $levels = substr_count($filesystem->normalizePath($rootPackage->getTargetDir()), '/') + 1;
-            $prefixes = implode(', ', array_map(function ($prefix) {
+            $prefixes = implode(', ', array_map(function ($prefix): string {
                 return var_export($prefix, true);
             }, array_keys($mainAutoload['psr-0'])));
             $baseDirFromTargetDirCode = $filesystem->findShortestPathCode($targetDir, $basePath, true);
@@ -441,7 +441,7 @@ public static function autoload(\$class)
      * @param array<string, true> $scannedFiles
      * @return array<class-string, string>
      */
-    private function addClassMapCode(Filesystem $filesystem, $basePath, $vendorPath, $dir, $excluded, $namespaceFilter, $autoloadType, array $classMap, array &$ambiguousClasses, array &$scannedFiles)
+    private function addClassMapCode(Filesystem $filesystem, $basePath, $vendorPath, $dir, $excluded, $namespaceFilter, $autoloadType, array $classMap, array &$ambiguousClasses, array &$scannedFiles): array
     {
         foreach ($this->generateClassMap($dir, $excluded, $namespaceFilter, $autoloadType, true, $scannedFiles) as $class => $path) {
             $pathCode = $this->getPathCode($filesystem, $basePath, $vendorPath, $path).",\n";
@@ -464,7 +464,7 @@ private function addClassMapCode(Filesystem $filesystem, $basePath, $vendorPath,
      * @param array<string, true> $scannedFiles
      * @return array<class-string, string>
      */
-    private function generateClassMap($dir, $excluded, $namespaceFilter, $autoloadType, $showAmbiguousWarning, array &$scannedFiles)
+    private function generateClassMap($dir, $excluded, $namespaceFilter, $autoloadType, $showAmbiguousWarning, array &$scannedFiles): array
     {
         if ($excluded) {
             // filter excluded patterns here to only use those matching $dir
@@ -554,7 +554,7 @@ public function parseAutoloads(array $packageMap, PackageInterface $rootPackage,
     {
         $rootPackageMap = array_shift($packageMap);
         if (is_array($filteredDevPackages)) {
-            $packageMap = array_filter($packageMap, function ($item) use ($filteredDevPackages) {
+            $packageMap = array_filter($packageMap, function ($item) use ($filteredDevPackages): bool {
                 return !in_array($item[0]->getName(), $filteredDevPackages, true);
             });
         } elseif ($filteredDevPackages) {
@@ -808,7 +808,7 @@ protected function getPlatformCheck(array $packageMap, $checkPlatform, array $de
 
         ksort($requiredExtensions);
 
-        $formatToPhpVersionId = function (Bound $bound) {
+        $formatToPhpVersionId = function (Bound $bound): int {
             if ($bound->isZero()) {
                 return 0;
             }
@@ -1229,7 +1229,7 @@ protected function parseAutoloadsType(array $packageMap, $type, RootPackageInter
                         $updir = null;
                         $path = Preg::replaceCallback(
                             '{^((?:(?:\\\\\\.){1,2}+/)+)}',
-                            function ($matches) use (&$updir) {
+                            function ($matches) use (&$updir): string {
                                 if (isset($matches[1])) {
                                     // undo preg_quote for the matched string
                                     $updir = str_replace('\\.', '.', $matches[1]);
@@ -1300,7 +1300,7 @@ protected function filterPackageMap(array $packageMap, RootPackageInterface $roo
             }
         }
 
-        $add = function (PackageInterface $package) use (&$add, $packages, &$include, $replacedBy) {
+        $add = function (PackageInterface $package) use (&$add, $packages, &$include, $replacedBy): void {
             foreach ($package->getRequires() as $link) {
                 $target = $link->getTarget();
                 if (isset($replacedBy[$target])) {
@@ -1318,7 +1318,7 @@ protected function filterPackageMap(array $packageMap, RootPackageInterface $roo
 
         return array_filter(
             $packageMap,
-            function ($item) use ($include) {
+            function ($item) use ($include): bool {
                 $package = $item[0];
                 foreach ($package->getNames() as $name) {
                     if (isset($include[$name])) {

src/Composer/Autoload/ClassMapGenerator.php

@@ -38,7 +38,7 @@ class ClassMapGenerator
      * @param string                     $file The name of the class map file
      * @return void
      */
-    public static function dump($dirs, $file)
+    public static function dump($dirs, $file): void
     {
         $maps = array();
 
@@ -61,7 +61,7 @@ public static function dump($dirs, $file)
      * @return array<class-string, string> A class map array
      * @throws \RuntimeException When the path is neither an existing file nor directory
      */
-    public static function createMap($path, $excluded = null, IOInterface $io = null, $namespace = null, $autoloadType = null, &$scannedFiles = array())
+    public static function createMap($path, $excluded = null, IOInterface $io = null, $namespace = null, $autoloadType = null, &$scannedFiles = array()): array
     {
         $basePath = $path;
         if (is_string($path)) {
@@ -157,7 +157,7 @@ public static function createMap($path, $excluded = null, IOInterface $io = null
      * @param  ?IOInterface             $io            IO object
      * @return array<int, class-string> valid classes
      */
-    private static function filterByNamespace($classes, $filePath, $baseNamespace, $namespaceType, $basePath, $io)
+    private static function filterByNamespace($classes, $filePath, $baseNamespace, $namespaceType, $basePath, $io): array
     {
         $validClasses = array();
         $rejectedClasses = array();
@@ -215,7 +215,7 @@ private static function filterByNamespace($classes, $filePath, $baseNamespace, $
      * @throws \RuntimeException
      * @return array<int, class-string> The found classes
      */
-    private static function findClasses($path)
+    private static function findClasses($path): array
     {
         $extraTypes = self::getExtraTypes();
 
@@ -296,7 +296,7 @@ private static function findClasses($path)
     /**
      * @return string
      */
-    private static function getExtraTypes()
+    private static function getExtraTypes(): string
     {
         static $extraTypes = null;
 

src/Composer/Autoload/PhpFileCleaner.php

@@ -51,7 +51,7 @@ class PhpFileCleaner
      * @param string[] $types
      * @return void
      */
-    public static function setTypeConfig($types)
+    public static function setTypeConfig($types): void
     {
         foreach ($types as $type) {
             self::$typeConfig[$type[0]] = array(
@@ -78,7 +78,7 @@ public function __construct($contents, $maxMatches)
     /**
      * @return string
      */
-    public function clean()
+    public function clean(): string
     {
         $clean = '';
 
@@ -152,7 +152,7 @@ public function clean()
     /**
      * @return void
      */
-    private function skipToPhp()
+    private function skipToPhp(): void
     {
         while ($this->index < $this->len) {
             if ($this->contents[$this->index] === '<' && $this->peek('?')) {
@@ -168,7 +168,7 @@ private function skipToPhp()
      * @param string $delimiter
      * @return void
      */
-    private function skipString($delimiter)
+    private function skipString($delimiter): void
     {
         $this->index += 1;
         while ($this->index < $this->len) {
@@ -187,7 +187,7 @@ private function skipString($delimiter)
     /**
      * @return void
      */
-    private function skipComment()
+    private function skipComment(): void
     {
         $this->index += 2;
         while ($this->index < $this->len) {
@@ -203,7 +203,7 @@ private function skipComment()
     /**
      * @return void
      */
-    private function skipToNewline()
+    private function skipToNewline(): void
     {
         while ($this->index < $this->len) {
             if ($this->contents[$this->index] === "\r" || $this->contents[$this->index] === "\n") {
@@ -217,7 +217,7 @@ private function skipToNewline()
      * @param string $delimiter
      * @return void
      */
-    private function skipHeredoc($delimiter)
+    private function skipHeredoc($delimiter): void
     {
         $firstDelimiterChar = $delimiter[0];
         $delimiterLength = \strlen($delimiter);
@@ -260,7 +260,7 @@ private function skipHeredoc($delimiter)
      * @param string $char
      * @return bool
      */
-    private function peek($char)
+    private function peek($char): bool
     {
         return $this->index + 1 < $this->len && $this->contents[$this->index + 1] === $char;
     }
@@ -270,7 +270,7 @@ private function peek($char)
      * @param ?array<int, string> $match
      * @return bool
      */
-    private function match($regex, array &$match = null)
+    private function match($regex, array &$match = null): bool
     {
         return Preg::isMatch($regex, $this->contents, $match, 0, $this->index);
     }

src/Composer/Command/AboutCommand.php

@@ -24,7 +24,7 @@ class AboutCommand extends BaseCommand
     /**
      * @return void
      */
-    protected function configure()
+    protected function configure(): void
     {
         $this
             ->setName('about')

src/Composer/Command/ArchiveCommand.php

@@ -41,7 +41,7 @@ class ArchiveCommand extends BaseCommand
     /**
      * @return void
      */
-    protected function configure()
+    protected function configure(): void
     {
         $this
             ->setName('archive')
@@ -168,7 +168,7 @@ protected function selectPackage(IOInterface $io, $packageName, $version = null)
         if (count($packages) > 1) {
             $package = reset($packages);
             $io->writeError('<info>Found multiple matches, selected '.$package->getPrettyString().'.</info>');
-            $io->writeError('Alternatives were '.implode(', ', array_map(function ($p) {
+            $io->writeError('Alternatives were '.implode(', ', array_map(function ($p): string {
                 return $p->getPrettyString();
             }, $packages)).'.');
             $io->writeError('<comment>Please use a more specific constraint to pick a different package.</comment>');

src/Composer/Command/BaseDependencyCommand.php

@@ -50,7 +50,7 @@ class BaseDependencyCommand extends BaseCommand
      * @param  bool            $inverted Whether to invert matching process (why-not vs why behaviour)
      * @return int             Exit code of the operation.
      */
-    protected function doExecute(InputInterface $input, OutputInterface $output, $inverted = false)
+    protected function doExecute(InputInterface $input, OutputInterface $output, $inverted = false): int
     {
         // Emit command event on startup
         $composer = $this->requireComposer();
@@ -90,7 +90,7 @@ protected function doExecute(InputInterface $input, OutputInterface $output, $in
         $needles = array($needle);
         if ($inverted) {
             foreach ($packages as $package) {
-                $needles = array_merge($needles, array_map(function (Link $link) {
+                $needles = array_merge($needles, array_map(function (Link $link): string {
                     return $link->getTarget();
                 }, $package->getReplaces()));
             }
@@ -136,7 +136,7 @@ protected function doExecute(InputInterface $input, OutputInterface $output, $in
      *
      * @return void
      */
-    protected function printTable(OutputInterface $output, $results)
+    protected function printTable(OutputInterface $output, $results): void
     {
         $table = array();
         $doubles = array();
@@ -172,7 +172,7 @@ protected function printTable(OutputInterface $output, $results)
      *
      * @return void
      */
-    protected function initStyles(OutputInterface $output)
+    protected function initStyles(OutputInterface $output): void
     {
         $this->colors = array(
             'green',
@@ -197,7 +197,7 @@ protected function initStyles(OutputInterface $output)
      *
      * @return void
      */
-    protected function printTree($results, $prefix = '', $level = 1)
+    protected function printTree($results, $prefix = '', $level = 1): void
     {
         $count = count($results);
         $idx = 0;
@@ -223,7 +223,7 @@ protected function printTree($results, $prefix = '', $level = 1)
      *
      * @return void
      */
-    private function writeTreeLine($line)
+    private function writeTreeLine($line): void
     {
         $io = $this->getIO();
         if (!$io->isDecorated()) {

src/Composer/Command/CheckPlatformReqsCommand.php

@@ -26,7 +26,7 @@ class CheckPlatformReqsCommand extends BaseCommand
     /**
      * @return void
      */
-    protected function configure()
+    protected function configure(): void
     {
         $this->setName('check-platform-reqs')
             ->setDescription('Check that platform requirements are satisfied.')
@@ -174,7 +174,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
      *
      * @return void
      */
-    protected function printTable(OutputInterface $output, $results)
+    protected function printTable(OutputInterface $output, $results): void
     {
         $rows = array();
         foreach ($results as $result) {

src/Composer/Command/ClearCacheCommand.php

@@ -25,7 +25,7 @@ class ClearCacheCommand extends BaseCommand
     /**
      * @return void
      */
-    protected function configure()
+    protected function configure(): void
     {
         $this
             ->setName('clear-cache')