diff --git a/examples/global.php b/examples/global.php
new file mode 100644
index 00000000..e94162fb
--- /dev/null
+++ b/examples/global.php
@@ -0,0 +1,5 @@
+<?php
+$a = 1234;
+$b = "hello";
+$_POST['key'] = random_int(1, PHP_INT_MAX);
+var_dump($GLOBALS);
diff --git a/phpunit/code/globals-array-access.php b/phpunit/code/globals-array-access.php
new file mode 100644
index 00000000..45116f52
--- /dev/null
+++ b/phpunit/code/globals-array-access.php
@@ -0,0 +1,6 @@
+<?php
+function main()
+{
+    $GLOBALS['test_key'] = 'hello';
+    var_dump($GLOBALS['test_key']);
+}
diff --git a/phpunit/code/optimizer-undefined-var.php b/phpunit/code/optimizer-undefined-var.php
new file mode 100644
index 00000000..e5e09a01
--- /dev/null
+++ b/phpunit/code/optimizer-undefined-var.php
@@ -0,0 +1,5 @@
+<?php
+function main()
+{
+    var_dump(in_array($key, $array));
+}
diff --git a/phpunit/src/CompactTest.php b/phpunit/src/CompactTest.php
new file mode 100644
index 00000000..deca2d9f
--- /dev/null
+++ b/phpunit/src/CompactTest.php
@@ -0,0 +1,35 @@
+<?php
+
+use PhpAot\Php\CompilerTest;
+use PhpAot\Php\Exception\TestError;
+
+class CompactTest extends \BaseTest
+{
+    public function testCompactThisOutsideClass(): void
+    {
+        $this->exec(
+            'Cannot use compact("this") outside of class method',
+            'compact-this-outside-class.php'
+        );
+    }
+
+    public function testCompactThisInsideClass(): void
+    {
+        $testFile = __DIR__ . '/../code/compact-this-inside-class.php';
+        $compiler = CompilerTest::create(ROOT_PATH);
+        $compiler->addFiles([$testFile]);
+        $compiler->prepareFile($testFile);
+        $compiler->convertFile($testFile);
+
+        $this->assertTrue(true); // 无异常即通过
+    }
+
+    public function testCompactThisMixedContext(): void
+    {
+        // compact('this') 在类方法内可通过，在普通函数内应 fatal
+        $this->exec(
+            'Cannot use compact("this") outside of class method',
+            'compact_no_this.php'
+        );
+    }
+}
diff --git a/phpunit/src/CountGlobalsTest.php b/phpunit/src/CountGlobalsTest.php
new file mode 100644
index 00000000..6a67f3ff
--- /dev/null
+++ b/phpunit/src/CountGlobalsTest.php
@@ -0,0 +1,33 @@
+<?php
+
+use PhpAot\Php\CompilerTest;
+
+/**
+ * 从 count-globals.php 拆解的测试用例：
+ *  - 优化器路径中未定义变量检测
+ *  - $GLOBALS 数组访问形式正常编译
+ */
+class CountGlobalsTest extends \BaseTest
+{
+    public function testOptimizerUndefinedVar()
+    {
+        // in_array($key, $array) 走优化器路径 (FuncCallOptimizer)
+        // 优化器检测到 $key 未定义后应回退到传统路径并给出明确错误
+        $this->exec(
+            'Undefined variable `$key`',
+            'optimizer-undefined-var.php'
+        );
+    }
+
+    public function testGlobalsArrayAccessAllowed()
+    {
+        // $GLOBALS['key'] 数组访问形式应正常通过编译
+        $testFile = __DIR__ . '/../code/globals-array-access.php';
+        $compiler = CompilerTest::create(ROOT_PATH);
+        $compiler->addFiles([$testFile]);
+        $compiler->prepareFile($testFile);
+        $compiler->convertFile($testFile);
+
+        $this->assertTrue(true); // 无异常即通过
+    }
+}