diff --git a/test.py b/test.py
index 9c9bfab5..1be714b0 100644
--- a/test.py
+++ b/test.py
@@ -186,6 +186,33 @@ def setUp(self):
     def tearDown(self):
         self.arg_lut_patcher.stop()
 
+    @patch("shared_utils.fixed_ranges")
+    @patch("shared_utils.single_fixed")
+    def test_process_enc_line(self, mock_single_fixed: Mock, mock_fixed_ranges: Mock):
+        """Test processing of encoding lines"""
+        # Setup mock return values
+        mock_fixed_ranges.findall.return_value = [(6, 2, "0x0D")]
+        mock_fixed_ranges.sub.return_value = "rd imm20"
+        mock_single_fixed.findall.return_value = []
+        mock_single_fixed.sub.return_value = "rd imm20"
+
+        # Create a mock for split() that returns the expected list
+        mock_split = Mock(return_value=["rd", "imm20"])
+        mock_single_fixed.sub.return_value = Mock(split=mock_split)
+
+        name, data = process_enc_line("lui rd imm20 6..2=0x0D", "rv_i")
+
+        self.logger = logging.getLogger()
+        self.logger.disabled = True
+        # Create a patch for arg_lut
+        self.arg_lut_patcher = patch.dict(
+            "shared_utils.arg_lut", {"rd": (11, 7), "imm20": (31, 12)}
+        )
+        self.arg_lut_patcher.start()
+
+    def tearDown(self):
+        self.arg_lut_patcher.stop()
+
     @patch("shared_utils.fixed_ranges")
     @patch("shared_utils.single_fixed")
     def test_process_enc_line(self, mock_single_fixed: Mock, mock_fixed_ranges: Mock):
@@ -226,7 +253,61 @@ def test_find_extension_file(self, mock_logging: Mock, mock_exists: Mock):
         with self.assertRaises(SystemExit):
             find_extension_file("rv32i", "/path/to/opcodes")
         mock_logging.assert_called_with("Extension rv32i not found.")
+        self.assertIn("rd", data["variable_fields"])
+        self.assertIn("imm20", data["variable_fields"])
+
+    @patch("os.path.exists")
+    @patch("shared_utils.logging.error")
+    def test_find_extension_file(self, mock_logging: Mock, mock_exists: Mock):
+        """Test extension file finding"""
+        # Test successful case - file exists in main directory
+        mock_exists.side_effect = [True, False]
+        result = find_extension_file("rv32i", "/path/to/opcodes")
+        self.assertEqual(result, "/path/to/opcodes/rv32i")
 
+        # Test successful case - file exists in unratified directory
+        mock_exists.side_effect = [False, True]
+        result = find_extension_file("rv32i", "/path/to/opcodes")
+        self.assertEqual(result, "/path/to/opcodes/unratified/rv32i")
+
+        # Test failure case - file doesn't exist anywhere
+        mock_exists.side_effect = [False, False]
+        with self.assertRaises(SystemExit):
+            find_extension_file("rv32i", "/path/to/opcodes")
+        mock_logging.assert_called_with("Extension rv32i not found.")
+
+    def test_process_standard_instructions(self):
+        """Test processing of standard instructions"""
+        lines = [
+            "add rd rs1 rs2 31..25=0 14..12=0 6..2=0x0C 1..0=3",
+            "sub rd rs1 rs2 31..25=0x20 14..12=0 6..2=0x0C 1..0=3",
+            "$pseudo add_pseudo rd rs1 rs2",  # Should be skipped
+            "$import rv32i::mul",  # Should be skipped
+        ]
+
+        instr_dict: InstrDict = {}
+        file_name = "rv32i"
+
+        with patch("shared_utils.process_enc_line") as mock_process_enc:
+            # Setup mock return values
+            mock_process_enc.side_effect = [
+                ("add", {"extension": ["rv32i"], "encoding": "encoding1"}),
+                ("sub", {"extension": ["rv32i"], "encoding": "encoding2"}),
+            ]
+
+            process_standard_instructions(lines, instr_dict, file_name)
+
+            # Verify process_enc_line was called twice (skipping pseudo and import)
+            self.assertEqual(mock_process_enc.call_count, 2)
+
+            # Verify the instruction dictionary was updated correctly
+            self.assertEqual(len(instr_dict), 2)
+            self.assertIn("add", instr_dict)
+            self.assertIn("sub", instr_dict)
+
+
+if __name__ == "__main__":
+    unittest.main()
     def test_process_standard_instructions(self):
         """Test processing of standard instructions"""
         lines = [