Mark file resource functions as having side effects

Fixes phpstan/phpstan#5461

resources/functionMetadata.php

@@ -816,7 +816,14 @@
 	'explode' => ['hasSideEffects' => false],
 	'expm1' => ['hasSideEffects' => false],
 	'extension_loaded' => ['hasSideEffects' => false],
+	'fclose' => ['hasSideEffects' => true],
 	'fdiv' => ['hasSideEffects' => false],
+	'feof' => ['hasSideEffects' => true],
+	'fflush' => ['hasSideEffects' => true],
+	'fgetc' => ['hasSideEffects' => true],
+	'fgetcsv' => ['hasSideEffects' => true],
+	'fgets' => ['hasSideEffects' => true],
+	'fgetss' => ['hasSideEffects' => true],
 	'file_exists' => ['hasSideEffects' => false],
 	'fileatime' => ['hasSideEffects' => false],
 	'filectime' => ['hasSideEffects' => false],
@@ -837,13 +844,25 @@
 	'finfo::buffer' => ['hasSideEffects' => false],
 	'finfo::file' => ['hasSideEffects' => false],
 	'floatval' => ['hasSideEffects' => false],
+	'flock' => ['hasSideEffects' => true],
 	'floor' => ['hasSideEffects' => false],
 	'fmod' => ['hasSideEffects' => false],
+	'fopen' => ['hasSideEffects' => true],
+	'fpassthru' => ['hasSideEffects' => true],
+	'fputcsv' => ['hasSideEffects' => true],
+	'fputs' => ['hasSideEffects' => true],
+	'fread' => ['hasSideEffects' => true],
+	'fscanf' => ['hasSideEffects' => true],
+	'fseek' => ['hasSideEffects' => true],
+	'fstat' => ['hasSideEffects' => true],
+	'ftell' => ['hasSideEffects' => true],
 	'ftok' => ['hasSideEffects' => false],
+	'ftruncate' => ['hasSideEffects' => true],
 	'func_get_arg' => ['hasSideEffects' => false],
 	'func_get_args' => ['hasSideEffects' => false],
 	'func_num_args' => ['hasSideEffects' => false],
 	'function_exists' => ['hasSideEffects' => false],
+	'fwrite' => ['hasSideEffects' => true],
 	'gc_enabled' => ['hasSideEffects' => false],
 	'gc_status' => ['hasSideEffects' => false],
 	'gd_info' => ['hasSideEffects' => false],

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -514,6 +514,8 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-4743.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-5017.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-2760.php');
+
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/file-resource-functions.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/file-resource-functions.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace FileResourceFunctions;
+
+use function PHPStan\Testing\assertType;
+
+class Bug5461
+{
+
+	public function run(): void
+	{
+		$fh = fopen('foo.txt', 'r');
+		if ($fh === false) {
+			throw new \InvalidArgumentException('Could not open file');
+		}
+
+		while (!feof($fh)) {
+			$data = (string)fread($fh, 1024);
+			assertType('bool', feof($fh));
+		}
+
+		fclose($fh);
+	}
+
+}
+
+class MoreTests
+{
+
+	/**
+	 * @param resource $fh
+	 */
+	public function test1($fh): void
+	{
+		if (fread($fh, 4) === 'data') {
+			assertType('string|false', fread($fh, 4));
+		}
+	}
+
+	public function test2(): void
+	{
+		if (fopen('foo.txt', 'r') === false) {
+			assertType('resource|false', fopen('foo.txt', 'r'));
+		}
+	}
+
+	/**
+	 * @param resource $fh
+	 */
+	public function test3($fh): void
+	{
+		if (ftell($fh) === 0) {
+			fseek($fh, 10);
+			assertType('int|false', ftell($fh));
+		}
+	}
+
+}