Add example tests

tests/Feature/UserTest.php

@@ -0,0 +1,32 @@
+<?php
+
+use TestProject\User;
+
+$makeUser = fn () => new User(18, 'John');
+
+test('class constructor')
+    ->expect($makeUser)
+    ->name->toBe('John')
+    ->age->toBe(18)
+    ->favorite_movies->toBeEmpty();
+
+test('tellName')
+    ->expect($makeUser)
+    ->tellName()->toBeString()->toContain('John');
+
+test('tellAge')
+    ->expect($makeUser)
+    ->tellAge()->toBeString()->toContain('18');
+
+test('addFavoriteMovie')
+    ->expect($makeUser)
+    ->addFavoriteMovie('Avengers')
+    ->toBeTrue()
+    ->favorite_movies->toContain('Avengers')->toHaveLength(1);
+
+test('removeFavoriteMovie')
+    ->expect($makeUser)
+    ->addFavoriteMovie('Avengers')->toBeTrue()
+    ->addFavoriteMovie('Justice League')->toBeTrue()
+    ->removeFavoriteMovie('Avengers')->toBeTrue()
+    ->favorite_movies->not->toContain('Avengers')->toHaveLength(1);