add DateFormatter and Calculator tests

src/DateFormatter.php

@@ -9,11 +9,11 @@ class DateFormatter
     /**
      * Get current part of the day
      *
+     * @param DateTime $dateTime
      * @return string
      */
-    public function getPartOfDay() : string
+    public function getPartOfDay(DateTime $dateTime) : string
     {
-        $dateTime    = new DateTime();
         $currentHour = $dateTime->format('G');
 
         if ($currentHour >= 0 && $currentHour < 6)

tests/CalculatorTest.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace IW\Tests\Workshop;
+
+use IW\Workshop\Calculator;
+use PHPUnit\Framework\TestCase;
+
+class CalculatorTest extends TestCase
+{
+    protected static $calculator;
+
+    /**
+     * @dataProvider additionProvider
+     */
+    public function testAdd(float $a, float $b, float $expected)
+    {
+        $this->assertEquals($expected, self::$calculator->add($a, $b));
+    }
+
+    public function additionProvider(): array
+    {
+        return [
+            [0, 0, 0],
+            [-1, 1, 0],
+            [40, 2, 42],
+            [PHP_INT_MIN, PHP_INT_MAX, 0]
+        ];
+    }
+
+    /**
+     * @dataProvider divisionProvider
+     */
+    public function testDivide(float $a, float $b, float $expected)
+    {
+        $this->assertEquals($expected, self::$calculator->divide($a, $b));
+        $this->expectException(\InvalidArgumentException::class);
+
+        self::$calculator->divide(1, 0);
+    }
+
+    public function divisionProvider(): array
+    {
+        return [
+            [1, 1, 1],
+            [0, 1, 0]
+        ];
+    }
+
+    protected function setUp()
+    {
+        parent::setUp();
+        self::$calculator = new Calculator();
+    }
+}

tests/DateFormatterTest.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace IW\Tests\Workshop;
+
+use IW\Workshop\DateFormatter;
+use PHPUnit\Framework\TestCase;
+
+class DateFormatterTest extends TestCase
+{
+
+    protected static $dateFormatter;
+
+    public function testGetPartOfDay()
+    {
+        $sampleData = [
+            [new \DateTime("2022-01-01T00:00:00+01:00"), "Night"],
+            [new \DateTime("2022-01-01T08:00:00+01:00"), "Morning"],
+            [new \DateTime("2022-01-01T14:00:00+01:00"), "Afternoon"],
+            [new \DateTime("2022-01-01T22:00:00+01:00"), "Evening"]
+        ];
+
+        array_map(function (array $line) {
+            $this->assertEquals(self::$dateFormatter->getPartOfDay($line[0]), $line[1]);
+        }, $sampleData);
+    }
+
+    protected function setUp()
+    {
+        parent::setUp();
+        self::$dateFormatter = new DateFormatter();
+    }
+}