Support stream_wrapper_register (#266)

Author: janedbal

README.md

@@ -115,6 +115,9 @@ parameters:
 #### Enum:
 - Detects usages caused by `BackedEnum::from`, `BackedEnum::tryFrom` and `UnitEnum::cases`
 
+#### StreamWrapper:
+- Detects usages caused by `stream_wrapper_register`
+
 Those providers are enabled by default, but you can disable them if needed.
 
 ## Excluding usages in tests:

rules.neon

@@ -99,6 +99,13 @@ services:
         arguments:
             enabled: %shipmonkDeadCode.usageProviders.nette.enabled%
 
+    -
+        class: ShipMonk\PHPStan\DeadCode\Provider\StreamWrapperUsageProvider
+        tags:
+            - shipmonk.deadCode.memberUsageProvider
+        arguments:
+            enabled: %shipmonkDeadCode.usageProviders.streamWrapper.enabled%
+
 
     -
         class: ShipMonk\PHPStan\DeadCode\Excluder\TestsUsageExcluder
@@ -199,6 +206,8 @@ parameters:
                 enabled: null
             nette:
                 enabled: null
+            streamWrapper:
+                enabled: true
         usageExcluders:
             tests:
                 enabled: false
@@ -255,6 +264,9 @@ parametersSchema:
             nette: structure([
                 enabled: schema(bool(), nullable())
             ])
+            streamWrapper: structure([
+                enabled: bool()
+            ])
         ])
         usageExcluders: structure([
             tests: structure([

src/Provider/StreamWrapperUsageProvider.php

@@ -0,0 +1,145 @@
+<?php declare(strict_types = 1);
+
+namespace ShipMonk\PHPStan\DeadCode\Provider;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Name;
+use PHPStan\Analyser\Scope;
+use ShipMonk\PHPStan\DeadCode\Graph\ClassMethodRef;
+use ShipMonk\PHPStan\DeadCode\Graph\ClassMethodUsage;
+use ShipMonk\PHPStan\DeadCode\Graph\UsageOrigin;
+use function in_array;
+
+/**
+ * See: https://php.net/manual/en/class.streamwrapper.php
+ */
+class StreamWrapperUsageProvider implements MemberUsageProvider
+{
+
+    private const STREAM_WRAPPER_METHODS = [
+        'dir_closedir',
+        'dir_opendir',
+        'dir_readdir',
+        'dir_rewinddir',
+        'mkdir',
+        'rename',
+        'rmdir',
+        'stream_cast',
+        'stream_close',
+        'stream_eof',
+        'stream_flush',
+        'stream_lock',
+        'stream_metadata',
+        'stream_open',
+        'stream_read',
+        'stream_seek',
+        'stream_set_option',
+        'stream_stat',
+        'stream_tell',
+        'stream_truncate',
+        'stream_write',
+        'unlink',
+        'url_stat',
+    ];
+
+    private bool $enabled;
+
+    public function __construct(
+        bool $enabled
+    )
+    {
+        $this->enabled = $enabled;
+    }
+
+    public function getUsages(
+        Node $node,
+        Scope $scope
+    ): array
+    {
+        if (!$this->enabled) {
+            return [];
+        }
+
+        if (!$node instanceof FuncCall) {
+            return [];
+        }
+
+        return $this->processFunctionCall($node, $scope);
+    }
+
+    /**
+     * @return list<ClassMethodUsage>
+     */
+    private function processFunctionCall(
+        FuncCall $node,
+        Scope $scope
+    ): array
+    {
+        $functionNames = $this->getFunctionNames($node, $scope);
+
+        if (in_array('stream_wrapper_register', $functionNames, true)) {
+            return $this->handleStreamWrapperRegister($node, $scope);
+        }
+
+        return [];
+    }
+
+    /**
+     * @return list<string>
+     */
+    private function getFunctionNames(
+        FuncCall $node,
+        Scope $scope
+    ): array
+    {
+        if ($node->name instanceof Name) {
+            return [$node->name->toString()];
+        }
+
+        $functionNames = [];
+        foreach ($scope->getType($node->name)->getConstantStrings() as $constantString) {
+            $functionNames[] = $constantString->getValue();
+        }
+
+        return $functionNames;
+    }
+
+    /**
+     * @return list<ClassMethodUsage>
+     */
+    private function handleStreamWrapperRegister(
+        FuncCall $node,
+        Scope $scope
+    ): array
+    {
+        $secondArg = $node->getArgs()[1] ?? null;
+        if ($secondArg === null) {
+            return [];
+        }
+
+        $argType = $scope->getType($secondArg->value);
+
+        $usages = [];
+        $classNames = [];
+        foreach ($argType->getConstantStrings() as $constantString) {
+            $classNames[] = $constantString->getValue();
+        }
+
+        foreach ($classNames as $className) {
+            foreach (self::STREAM_WRAPPER_METHODS as $methodName) {
+                $usages[] = new ClassMethodUsage(
+                    UsageOrigin::createRegular($node, $scope),
+                    new ClassMethodRef(
+                        $className,
+                        $methodName,
+                        false,
+                    ),
+                );
+            }
+        }
+
+        return $usages;
+    }
+
+}

tests/Rule/DeadCodeRuleTest.php

@@ -47,6 +47,7 @@
 use ShipMonk\PHPStan\DeadCode\Provider\PhpUnitUsageProvider;
 use ShipMonk\PHPStan\DeadCode\Provider\ReflectionBasedMemberUsageProvider;
 use ShipMonk\PHPStan\DeadCode\Provider\ReflectionUsageProvider;
+use ShipMonk\PHPStan\DeadCode\Provider\StreamWrapperUsageProvider;
 use ShipMonk\PHPStan\DeadCode\Provider\SymfonyUsageProvider;
 use ShipMonk\PHPStan\DeadCode\Provider\TwigUsageProvider;
 use ShipMonk\PHPStan\DeadCode\Provider\VendorUsageProvider;
@@ -863,6 +864,7 @@ public static function provideFiles(): Traversable
         yield 'provider-nette' => [__DIR__ . '/data/providers/nette.php'];
         yield 'provider-apiphpdoc' => [__DIR__ . '/data/providers/api-phpdoc.php', self::requiresPhp(8_01_00)];
         yield 'provider-enum' => [__DIR__ . '/data/providers/enum.php', self::requiresPhp(8_01_00)];
+        yield 'provider-stream-wrapper' => [__DIR__ . '/data/providers/stream-wrapper.php'];
 
         // excluders
         yield 'excluder-tests' => [[__DIR__ . '/data/excluders/tests/src/code.php', __DIR__ . '/data/excluders/tests/tests/code.php']];
@@ -1009,6 +1011,9 @@ private function getMemberUsageProviders(): array
                 self::getContainer()->getByType(ReflectionProvider::class),
                 $this->providersEnabled,
             ),
+            new StreamWrapperUsageProvider(
+                $this->providersEnabled,
+            ),
             new SymfonyUsageProvider(
                 $this->createContainerMockWithSymfonyConfig(),
                 $this->providersEnabled,

tests/Rule/data/providers/stream-wrapper.php

@@ -0,0 +1,14 @@
+<?php declare(strict_types = 1);
+
+namespace StreamWrapper;
+
+class MyStreamWrapper
+{
+    public function stream_open($path, $mode, $options, &$opened_path) {}
+    public function stream_read($count) {}
+    public function unrelated($path, $mode, $options, &$opened_path) {} // error: Unused StreamWrapper\MyStreamWrapper::unrelated
+}
+
+function testAll() {
+    stream_wrapper_register('myprotocol', MyStreamWrapper::class);
+}