add tests for covers attribute

tests/Features/Covers.php

@@ -0,0 +1,46 @@
+<?php
+
+use Pest\Factories\Attributes\Covers;
+
+$runCounter = 0;
+
+class TestCoversClass1 {}
+class TestCoversClass2 {}
+
+it('uses the correct PHPUnit attribute for class', function () {
+    $attributes = (new ReflectionClass($this))->getAttributes();
+
+    expect($attributes[0]->getName())->toBe('PHPUnit\Framework\Attributes\CoversClass');
+    expect($attributes[0]->getArguments()[0])->toBe('P\Tests\Features\TestCoversClass1');
+})->coversClass(TestCoversClass1::class);
+
+it('uses the correct PHPUnit attribute for function', function () {
+    $attributes = (new ReflectionClass($this))->getAttributes();
+
+    expect($attributes[1]->getName())->toBe('PHPUnit\Framework\Attributes\CoversFunction');
+    expect($attributes[1]->getArguments()[0])->toBe('foo');
+})->coversFunction('foo');
+
+it('uses the correct PHPUnit attribute for nothing', function () {
+    $attributes = (new ReflectionClass($this))->getAttributes();
+
+    expect($attributes[2]->getName())->toBe('PHPUnit\Framework\Attributes\CoversNothing');
+})->coversNothing();
+
+it('removes duplicated attributes', function () {
+    $attributes = (new ReflectionClass($this))->getAttributes();
+
+    expect($attributes)->toHaveCount(7); // 3 classes, 3 functions, 1 nothing
+
+    expect($attributes[3]->getName())->toBe('PHPUnit\Framework\Attributes\CoversClass');
+    expect($attributes[3]->getArguments()[0])->toBe('P\Tests\Features\TestCoversClass2');
+    expect($attributes[4]->getName())->toBe('PHPUnit\Framework\Attributes\CoversClass');
+    expect($attributes[4]->getArguments()[0])->toBe('Pest\Factories\Attributes\Covers');
+    expect($attributes[5]->getName())->toBe('PHPUnit\Framework\Attributes\CoversFunction');
+    expect($attributes[5]->getArguments()[0])->toBe('bar');
+    expect($attributes[6]->getName())->toBe('PHPUnit\Framework\Attributes\CoversFunction');
+    expect($attributes[6]->getArguments()[0])->toBe('baz');
+})
+    ->coversClass(TestCoversClass2::class, TestCoversClass1::class, Covers::class)
+    ->coversNothing()
+    ->coversFunction('bar', 'foo', 'baz');