diff --git a/backend/tests/test_ast_analyzer.py b/backend/tests/test_ast_analyzer.py
index 20fa05f..28f5862 100644
--- a/backend/tests/test_ast_analyzer.py
+++ b/backend/tests/test_ast_analyzer.py
@@ -21,6 +21,10 @@ def test_mutable_default_set():
     issues = _types("def f(x=set()): pass\ndef g(y={1, 2}): pass")
     assert "Mutable Default Argument" in issues
 
+def test_mutable_keyword_only_default_detected():
+    issues = _types("def f(*, options={}): pass")
+    assert "Mutable Default Argument" in issues
+
 def test_no_mutable_default_with_none():
     issues = _types("def f(x=None): pass")
     assert "Mutable Default Argument" not in issues
@@ -104,6 +108,10 @@ def test_unreachable_after_raise():
     code = "def f():\n    raise ValueError()\n    x = 1"
     assert "Unreachable Code" in _types(code)
 
+def test_unreachable_in_async_function_detected():
+    code = "async def f():\n    return 1\n    await other()"
+    assert "Unreachable Code" in _types(code)
+
 def test_reachable_code_not_flagged():
     code = "def f():\n    x = 1\n    return x"
     assert "Unreachable Code" not in _types(code)
@@ -192,6 +200,16 @@ def test_used_alias_not_flagged():
     issues = analyze(code)
     assert not any(i["type"] == "Unused Import" for i in issues)
 
+def test_used_from_import_alias_not_flagged():
+    code = "from pathlib import Path as P\nroot = P('.')\n"
+    issues = analyze(code)
+    assert not any(i["type"] == "Unused Import" for i in issues)
+
+def test_star_import_not_flagged_as_unused_import():
+    code = "from math import *\nvalue = sqrt(4)\n"
+    issues = analyze(code)
+    assert not any(i["type"] == "Unused Import" for i in issues)
+
 def test_too_many_returns_exact_boundary():
     # 3 returns = should NOT flag
     code = "def f(x):\n    if x==1: return 1\n    if x==2: return 2\n    return 3\n"