.vscode/settings.json

 {
-    "phpunit.phpunit": "demotp6/vendor/bin/phpunit",
+    "phpunit.phpunit": "demophpunit/vendor/bin/phpunit",
     "phpunit.php": "php",
     "phpunit.args": [
         "--colors",

demophpunit/composer.json

@@ -6,7 +6,7 @@
     },
     "autoload": {
         "psr-4": {
-            "Admin\\Demophpunit\\": "src/"
+            "app\\": "src/app"
         }
     },
     "authors": [
@@ -15,5 +15,7 @@
             "email": "1192129692@qq.com"
         }
     ],
-    "require": {}
+    "require": {
+        "monolog/monolog": "^3.5"
+    }
 }

demophpunit/src/Demo/DemoAa.php

-<?php
-namespace Admin\Demophpunit\Demo;
-class DemoAa
-{
-    public function Aaa() {
-        print("Aaaaaa");
-    }
-}

demophpunit/src/Demo/DemoBb.php

-<?php
-namespace Admin\Demophpunit\Demo;
-class DemoBb{
-    function Bbb() {
-        print("Bbbbbbb");
-    }
-}
\ No newline at end of file

demophpunit/src/Index/Ccc.php

-<?php
-namespace Admin\Demophpunit\Index;
-
-class Ccc{
-    function Ccc() {
-        print("Cccccc22222");
-    }
-}
\ No newline at end of file

demophpunit/src/app/User.php

+<?php
+namespace app;
+class User{
+    function say() {
+        print "hello";
+    }
+}
\ No newline at end of file

demophpunit/src/index.php

 <?php
-namespace Admin\Demophpunit;
-use Admin\Demophpunit\Demo\DemoAa;
-// [ 应用入口文件 ]
-// namespace think;
-
+use app\User;
+use Monolog\Level;
+use Monolog\Logger;
+use Monolog\Handler\StreamHandler;
 require __DIR__ . '/../vendor/autoload.php';
-$demo = new  DemoAa();
-$demo->Aaa();
-// print("aaaa");
\ No newline at end of file
+$user = new User();
+$user->say();
+
+
+// create a log channel
+$log = new Logger('name');
+$log->pushHandler(new StreamHandler('path/to/your.log', Level::Warning));
+
+// add records to the log
+$log->warning('Foo');
+$log->error('Bar');

demophpunit/tests/DemoTest.php

 <?php
+
 use PHPUnit\Framework\TestCase;
-use Admin\Demophpunit\Demo\DemoAa;
-use Admin\Demophpunit\Demo\DemoBb;
-use Admin\Demophpunit\Index\Ccc;
-use function PHPUnit\Framework\assertNull;
+use app\User;
+use Monolog\Level;
+use Monolog\Logger;
+use Monolog\Handler\StreamHandler;
+use function PHPUnit\Framework\assertTrue;
 
 class DemoTest extends TestCase
 {
+    function tearDown(): void
+    {
+        assertTrue(true);
+    }
     public function testAaa(){
-        $aa=new DemoAa();
-        $aa->Aaa();
-        $bb=new DemoBb;
-        $bb->Bbb();
-        $cc=new Ccc();
-        $cc->Ccc();
-        print("aaaaaa");
-        print("??????");
-        print("cccccc");
-        // phpinfo();
-        $this->assertEmpty("","???");
-        
+      $user=new User();
+      $user->say();
+    }
+
+    function testLog() {
+      // create a log channel
+      $log = new Logger('name');
+      $log->pushHandler(new StreamHandler('php://stdout', Level::Warning));
+
+      // add records to the log
+      $log->warning('Foo');
+      $log->error('Bar');
     }
 }