Implemented the Path assessment including unit tests

Aurolieen/Path.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Aurolieen;
+
+/**
+ * Assessment 4. Path
+ *
+ * @note I have omitted invalid input checks as per the instructions that the input will always be valid.
+ *
+ * Class Path
+ * @package Aurolieen
+ */
+class Path
+{
+    public $currentPath;
+    private $nodes = [];
+
+    /**
+     * Path constructor.
+     * Traverses the path pointer to the provided base path.
+     *
+     * @param string $path The base path.
+     */
+    function __construct($path)
+    {
+        $this->cd($path);
+    }
+
+    /**
+     * Moves the path pointer to the specified new location and updates the string representation of the current path.
+     *
+     * @param string $newPath New path to traverse to.
+     */
+    public function cd($newPath)
+    {
+        $newNodes = explode('/', $newPath);
+        foreach ($newNodes as $index => $node) {
+            switch ($node)
+            {
+                case '':                // If the index equals 0, reset to the root otherwise do nothing.
+                    if ($index === 0) $this->nodes = [];
+                    break;
+                case '..':              // Move up one node.
+                    array_pop($this->nodes);
+                    break;
+                default:                // Add a new node.
+                    array_push($this->nodes, $node);
+                    break;
+            }
+        }
+        $this->currentPath = '/' . implode('/', $this->nodes);
+    }
+}
+
+$path = new Path('/a/b/c/d');
+$path->cd('../x');
+echo $path->currentPath;

Aurolieen/tests/PathTest.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace Aurolieen\Tests;
+
+use Aurolieen\Path;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Test suite for the Path assessment class.
+ *
+ * Class PathTest
+ * @package Aurolieen\Tests
+ */
+class PathTest extends TestCase
+{
+    /**
+     * Tests that the constructor sets the currentPath attribute to the same string as the input path.
+     */
+    public function testBasePath()
+    {
+        $base = new Path('/a/b/c/d');
+        $this->assertEquals('/a/b/c/d', $base->currentPath);
+    }
+
+    /**
+     * Tests that absolute paths get appended to the current path.
+     *
+     * @depends testBasePath
+     */
+    public function testAbsolutePaths()
+    {
+        $base = new Path('/');
+        $base->cd('a/b/c/d');
+        $this->assertEquals('/a/b/c/d', $base->currentPath);
+        $base = new Path('/a/b/c/d');
+        $base->cd('x');
+        $this->assertEquals('/a/b/c/d/x', $base->currentPath);
+    }
+
+    /**
+     * Tests that relative paths traverse up the path when needed.
+     *
+     * @depends testBasePath
+     */
+    public function testRelativePaths()
+    {
+        $base = new Path('/');
+        $base->cd('a/b/../d');
+        $this->assertEquals('/a/d', $base->currentPath);
+        $base = new Path('/a/b/c/d');
+        $base->cd('../x');
+        $this->assertEquals('/a/b/c/x', $base->currentPath);
+        $base = new Path('/a/b/c/d');
+        $base->cd('../../../../x');
+        $this->assertEquals('/x', $base->currentPath);
+    }
+
+    /**
+     * Tests that some of the weirder valid paths produce the correct results.
+     *
+     * @depends testBasePath
+     */
+    public function testOddPaths()
+    {
+        $base = new Path('/');
+        $base->cd('///////////////////a');
+        $this->assertEquals('/a', $base->currentPath);
+        $base = new Path('/');
+        $base->cd('../x/../x/../a');
+        $this->assertEquals('/a', $base->currentPath);
+        $base = new Path('/');
+        $base->cd('a/..//..//a//b//cde');
+        $this->assertEquals('/a/b/cde', $base->currentPath);
+    }
+}