✅ Adding phpunit

composer.json

@@ -18,6 +18,11 @@
             "ShibuyaKosuke\\LaravelYasumi\\": "src/"
         }
     },
+    "autoload-dev": {
+        "psr-4": {
+            "ShibuyaKosuke\\LaravelYasumi\\Tests\\": "tests/"
+        }
+    },
     "extra": {
         "laravel": {
             "providers": [
@@ -27,5 +32,11 @@
                 "Holiday": "ShibuyaKosuke\\LaravelYasumi\\Facades\\Holiday"
             }
         }
+    },
+    "scripts": {
+        "test": "vendor/bin/phpunit"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^10.5"
     }
 }

phpunit.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" colors="true" bootstrap="vendor/autoload.php" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd" cacheDirectory=".phpunit.cache">
+  <coverage/>
+  <testsuites>
+    <testsuite name="Application Test Suite">
+      <directory>./tests</directory>
+    </testsuite>
+  </testsuites>
+  <php>
+    <env name="APP_ENV" value="testing"/>
+  </php>
+  <source>
+    <include>
+      <directory suffix=".php">./src</directory>
+    </include>
+  </source>
+</phpunit>

tests/HolidayTest.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShibuyaKosuke\LaravelYasumi\Tests;
+
+use Illuminate\Config\Repository;
+use Illuminate\Support\Carbon;
+use ShibuyaKosuke\LaravelYasumi\Holiday;
+
+class HolidayTest extends TestCase
+{
+    public function testCanGetHolidays(): void
+    {
+        $config = new Repository([
+            'yasumi' => [
+                'country' => 'Japan',
+                'locale' => 'ja_JP'
+            ]
+        ]);
+        $holiday = new Holiday($config);
+        $newYear = Carbon::make('2020-01-01');
+        $holidayResult = $holiday->get($newYear);
+        $this->assertEquals('元日', $holidayResult);
+    }
+}

tests/TestCase.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShibuyaKosuke\LaravelYasumi\Tests;
+
+abstract class TestCase extends \PHPUnit\Framework\TestCase
+{
+
+}