Implemented the FileOwners assessment including unit tests

Aurolieen/FileOwners.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Aurolieen;
+
+/**
+ * Assessment 1. File Owners
+ *
+ * Class FileOwners
+ * @package Aurolieen
+ */
+class FileOwners
+{
+    /**
+     * Groups the provided files by their owners.
+     *
+     * @param array $files Map containing file keys and owner values.
+     * @return array The input files grouped by their owners.
+     */
+    public function groupByOwners($files)
+    {
+        if (empty($files) || !is_array($files)) return [];
+        $grouped = [];
+        foreach ($files as $file => $owner)
+        {
+            if (!is_string($file) || !is_string($owner)) continue;
+            if (!key_exists($owner, $grouped)) $grouped[$owner] = [];
+            $grouped[$owner][] = $file;
+        }
+        return $grouped;
+    }
+}
+
+$files = [
+    "Input.txt" => "Randy",
+    "Code.py" => "Stan",
+    "Output.txt" => "Randy"
+];
+$fileOwners = new FileOwners;
+var_dump($fileOwners->groupByOwners($files));

Aurolieen/tests/FileOwnersTest.php

@@ -0,0 +1,102 @@
+<?php
+
+namespace Aurolieen\Tests;
+
+use Aurolieen\FileOwners;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Test suite for the FilerOwners assessment class.
+ *
+ * Class FileOwnersTest
+ * @package Aurolieen\Tests
+ */
+class FileOwnersTest extends TestCase
+{
+    protected $fileOwners;
+
+    /**
+     * Instantiates a FileOwners object on which the tests are executed.
+     */
+    public function setUp(): void
+    {
+        $this->fileOwners = new FileOwners();
+    }
+
+    /**
+     * Tests that the output is an array of files grouped by their owners using a random set of file/author combinations
+     * as input.
+     *
+     * @param array $input Well formed array of random files and owners.
+     * @dataProvider randomInputProvider
+     */
+    public function testRandomInput($input)
+    {
+        $output = $this->fileOwners->groupByOwners($input);
+        foreach ($input as $file => $owner)
+        {
+            $this->assertArrayHasKey($owner, $output);
+            $this->assertContains($file, $output[$owner]);
+        }
+    }
+
+    /**
+     * Tests that the output is empty when the input is empty.
+     */
+    public function testEmptyInput()
+    {
+        $this->assertEquals([], $this->fileOwners->groupByOwners([]));
+    }
+
+    /**
+     * Tests that any input elements that aren't strings are skipped.
+     *
+     * @param mixed $expected The expected output.
+     * @param mixed $input Invalid input.
+     * @dataProvider invalidInputProvider
+     */
+    public function testInvalidInput($expected, $input)
+    {
+        $this->assertEquals($expected, $this->fileOwners->groupByOwners($input));
+    }
+
+    /**
+     * Provides invalid input data.
+     *
+     * @return array Array of arrays containing invalid input / expected output combinations.
+     */
+    public function invalidInputProvider()
+    {
+        return [
+            [[], [1, 2, 3]],
+            [
+                ["Randy" => ["file.txt", ""]],
+                ["file.txt" => "Randy", "file2.txt" => null, "file3.txt" => 2, null => "Randy"]
+            ],
+            [[], 3]
+        ];
+    }
+
+    /**
+     * Provides valid random input data.
+     */
+    public function randomInputProvider()
+    {
+        $randomInputArrays = [];
+        for ($i = 0; $i < 5; $i++)
+        {
+            $randomInputArray = [];
+            $randJLength = rand(4, 10);
+            for ($j = 0; $j < $randJLength; $j++)
+            {
+                $file = substr(str_shuffle('abcdefghijklmnopqrstuvwxyz'), 0, rand(3,10));
+                $owner = substr(str_shuffle('abcdefghijklmnopqrstuvwxyz'), 0, rand(3,10));
+                $randomInputArray[$file] = $owner;
+            }
+            // Create a duplicate owner.
+            $randomInputArray[substr(str_shuffle('abcdefghijklmnopqrstuvwxyz'), 0, rand(3,10))] = reset($randomInputArray);
+            $randomInputArrays[] = [$randomInputArray];
+        }
+        return $randomInputArrays;
+    }
+}