Enhancement: Add tests for TestCase

tests/_files/TestWithDifferentOutput.php

@@ -0,0 +1,39 @@
+<?php declare(strict_types=1);
+/*
+ * This file is part of PHPUnit.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+use PHPUnit\Framework\TestCase;
+
+final class TestWithDifferentOutput extends TestCase
+{
+    public function testThatDoesNotGenerateOutput(): void
+    {
+        $this->assertTrue(true);
+    }
+
+    public function testThatExpectsOutputRegex(): void
+    {
+        $this->expectOutputRegex('.*');
+
+        print 'Hello!';
+    }
+
+    public function testThatExpectsOutputString(): void
+    {
+        $this->expectOutputString('Hello!');
+
+        print 'Hello!';
+    }
+
+    public function testThatGeneratesOutput(): void
+    {
+        print 'Hello!';
+
+        $this->assertTrue(true);
+    }
+}

tests/unit/Framework/TestCaseTest.php

@@ -1086,6 +1086,42 @@ public function testHasFailedReturnsFalseWhenTestHasEmittedWarning(): void
         $this->assertFalse($test->hasFailed());
     }
 
+    public function testHasOutputReturnsFalseWhenTestDoesNotGenerateOutput(): void
+    {
+        $test = new \TestWithDifferentOutput('testThatDoesNotGenerateOutput');
+
+        $test->run();
+
+        $this->assertFalse($test->hasOutput());
+    }
+
+    public function testHasOutputReturnsFalseWhenTestExpectsOutputRegex(): void
+    {
+        $test = new \TestWithDifferentOutput('testThatExpectsOutputRegex');
+
+        $test->run();
+
+        $this->assertFalse($test->hasOutput());
+    }
+
+    public function testHasOutputReturnsFalseWhenTestExpectsOutputString(): void
+    {
+        $test = new \TestWithDifferentOutput('testThatExpectsOutputString');
+
+        $test->run();
+
+        $this->assertFalse($test->hasOutput());
+    }
+
+    public function testHasOutputReturnsTrueWhenTestGeneratesOutput(): void
+    {
+        $test = new \TestWithDifferentOutput('testThatGeneratesOutput');
+
+        $test->run();
+
+        $this->assertTrue($test->hasOutput());
+    }
+
     /**
      * @return array<string, array>
      */