Implemented Todo class

src/Todo.php

@@ -0,0 +1,56 @@
+<?php declare(strict_types=1);
+
+namespace MMK2410\MyTodoList;
+
+class Todo
+{
+    const ExceptionMsgInvalidTitle = "Empty task title not allowed";
+
+    private string $title;
+    private string $state;
+
+    public function __construct(string $title)
+    {
+        $this->validateTitle($title);
+        $this->title = $title;
+        $this->state = TodoStates::Todo;
+    }
+
+    public function getTitle(): string
+    {
+        return $this->title;
+    }
+
+    public function setTitle(string $title): void
+    {
+        $this->validateTitle($title);
+        $this->title = $title;
+    }
+
+    public function getStatus(): string
+    {
+        return $this->state;
+    }
+
+    public function setState(string $state): void
+    {
+        $this->validateState($state);
+        $this->state = $state;
+    }
+
+    private function validateTitle(string $title): void
+    {
+        if (empty($title)) {
+            throw new \InvalidArgumentException(self::ExceptionMsgInvalidTitle);
+        }
+    }
+
+    private function validateState(string $state): void
+    {
+        $reflect = new \ReflectionClass(TodoStates::class);
+        $constantFound = $reflect->getConstant($state);
+        if ($constantFound === FALSE) {
+            throw new \InvalidArgumentException("Invalid state tried to set.");
+        }
+    }
+}

tests/TodoTest.php

@@ -0,0 +1,67 @@
+<?php declare(strict_types=1);
+
+use MMK2410\MyTodoList\Todo;
+use MMK2410\MyTodoList\TodoStates;
+use PHPUnit\Framework\TestCase;
+
+class TodoTest extends TestCase
+{
+    public function testCreateTodo(): void
+    {
+        $title = "Some task";
+        $todo = new Todo($title);
+        $this->assertEquals(
+            $title,
+            $todo->getTitle(),
+            "Expected title '$title', but got '{$todo->getTitle()}'"
+        );
+    }
+
+    public function testDontCreateEmptyTodo(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage(Todo::ExceptionMsgInvalidTitle);
+        new Todo("");
+    }
+
+    public function testUpdateTitle(): void
+    {
+        $anotherTitle = "Another title";
+        $todo = new Todo("Some title");
+        $todo->setTitle($anotherTitle);
+        $this->assertEquals(
+            $anotherTitle,
+            $todo->getTitle(),
+            "Expected new title $anotherTitle, but got {$todo->getTitle()}"
+        );
+    }
+
+    public function testNewTodoState(): void
+    {
+        $todo = new Todo("stub");
+        $this->assertEquals(
+            TodoStates::Todo,
+            $todo->getStatus(),
+            "Expected todo state 'Todo', but got {$todo->getStatus()}"
+        );
+    }
+
+    public function testChangeTodoState(): void
+    {
+        $todo = new Todo("stub");
+        $todo->setState(TodoStates::Done);
+        $this->assertEquals(
+            TodoStates::Done,
+            $todo->getStatus(),
+            "Expected todo state 'Done', but got {$todo->getStatus()}"
+        );
+    }
+
+    public function testSetBogusTodoState(): void
+    {
+       $todo = new Todo("stub");
+       $this->expectException(\InvalidArgumentException::class);
+       $this->expectExceptionMessage("Invalid state tried to set.");
+       $todo->setState("bogus");
+    }
+}