added FileSystem::resolvePath() [Closes #308]

Author: dg

src/Utils/FileSystem.php

@@ -305,6 +305,19 @@ public static function joinPaths(string ...$paths): string
 	}
 
 
+	/**
+	 * Resolves a path against a base path. If the path is absolute, returns it directly, if it's relative, joins it with the base path.
+	 */
+	public static function resolvePath(string $basePath, string $path): string
+	{
+		return match (true) {
+			self::isAbsolute($path) => self::platformSlashes($path),
+			$path === '' => self::platformSlashes($basePath),
+			default => self::joinPaths($basePath, $path),
+		};
+	}
+
+
 	/**
 	 * Converts backslashes to slashes.
 	 */

tests/Utils/FileSystem.resolvePath.phpt

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+use Nette\Utils\FileSystem;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+test('absolute paths', function () {
+	$S = DIRECTORY_SEPARATOR;
+	Assert::same("{$S}abs{$S}path", FileSystem::resolvePath('/base/dir', '/abs/path'));
+	Assert::same("c:{$S}abs{$S}path", FileSystem::resolvePath('/base/dir', 'c:/abs/path'));
+	Assert::same('http://example.com', FileSystem::resolvePath('/base/dir', 'http://example.com'));
+	Assert::same("{$S}", FileSystem::resolvePath('base', '/'));
+});
+
+test('relative paths', function () {
+	$S = DIRECTORY_SEPARATOR;
+	Assert::same("base{$S}rel", FileSystem::resolvePath('base', 'rel'));
+	Assert::same("{$S}base{$S}rel", FileSystem::resolvePath('/base', 'rel'));
+	Assert::same("{$S}base{$S}dir{$S}file.txt", FileSystem::resolvePath('/base/dir/', 'file.txt'));
+});
+
+test('path normalization', function () {
+	$S = DIRECTORY_SEPARATOR;
+	Assert::same("{$S}base{$S}", FileSystem::resolvePath('/base/dir', '../'));
+	Assert::same("{$S}base{$S}other", FileSystem::resolvePath('/base/dir/', '../other'));
+	Assert::same("{$S}..{$S}other", FileSystem::resolvePath('/base/', '../../other'));
+	Assert::same("base{$S}dir", FileSystem::resolvePath('base/./dir/../', 'dir'));
+});
+
+test('special cases', function () {
+	$S = DIRECTORY_SEPARATOR;
+	Assert::same('base', FileSystem::resolvePath('base', ''));
+	Assert::same("base{$S}dir", FileSystem::resolvePath('base/dir', ''));
+	Assert::same('', FileSystem::resolvePath('', ''));
+});