Add remaining test files

tests/test_utils.py

@@ -0,0 +1,19 @@
+import pytest
+from src.utils import ShellParser
+
+class TestShellParser:
+    def test_tokenize_simple(self):
+        tokens = ShellParser.tokenize("echo hello")
+        assert "echo" in tokens
+
+    def test_extract_variables(self):
+        vars = ShellParser.extract_variables("echo $VAR1 and $VAR2")
+        assert "VAR1" in vars and "VAR2" in vars
+
+    def test_is_safe_command(self):
+        is_safe, issues = ShellParser.is_safe("ls -la /tmp")
+        assert is_safe
+
+    def test_is_safe_dangerous(self):
+        is_safe, issues = ShellParser.is_safe("rm -rf $TARGET")
+        assert not is_safe