added test for CommandLineParser

Author: Alexsey-VR

tests/CommandLineParserTest.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace Differ\tests;
+
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\CoversMethod;
+use Differ\CommandLineParser;
+
+#[CoversClass(CommandLineParser::class)]
+#[CoversMethod(CommandLineParser::class, 'setFileNames')]
+#[CoversMethod(CommandLineParser::class, 'getFileNames')]
+class CommandLineParserTest extends TestCase
+{
+    private $fixturesFileHandler;
+    private $fixturesData;
+
+    protected function setUp(): void
+    {
+        $this->fixturesFileHandler = fopen(__DIR__ . "/../fixtures/docopt.txt", "r");
+        $docoptInput = [];
+        while (($docoptInput[] = fgets($this->fixturesFileHandler, 4096)) !== false);
+        $this->fixturesData = implode("\n", $docoptInput);
+    }
+    
+    public function testFileNames()
+    {
+        $cmdLineParser = new CommandLineParser($this->fixturesData);
+
+        $fileNames = [
+            "FILE1" => __DIR__ . "/../file1.json",
+            "FILE2" => __DIR__ . "/../file2.json"
+        ];
+
+        $this->assertInstanceOf(CommandLineParser::class, $cmdLineParser->setFileNames($fileNames));
+
+        $this->assertEquals($fileNames, $cmdLineParser->setFileNames($fileNames)
+                                                      ->getFileNames());
+    }
+
+    public function testExecute()
+    {
+        $cmdLineParser = new CommandLineParser($this->fixturesData);
+
+        $stub = $this->createStub(CommandLineParser::class);
+
+        $this->assertInstanceOf(CommandLineParser::class, $cmdLineParser->execute($stub));
+    }
+
+    protected function tearDown(): void
+    {
+        fclose($this->fixturesFileHandler);
+    }
+}