Fix 222 (#296)

* Added exceptions to packer and parser

* added exception tests

* improve style

* linter is annoying

* static analysis fix

* static analysis fix2

* static analysis fix3

* clean up the code

* update exceptions

* style1

* style2

can/packer_pyx.pyx

@@ -20,9 +20,11 @@ cdef class CANPacker:
     map[int, int] address_to_size
 
   def __init__(self, dbc_name):
-    self.packer = new cpp_CANPacker(dbc_name)
     self.dbc = dbc_lookup(dbc_name)
-
+    if not self.dbc:
+      raise RuntimeError("Can't lookup" + dbc_name)
+      
+    self.packer = new cpp_CANPacker(dbc_name)
     num_msgs = self.dbc[0].num_msgs
     for i in range(num_msgs):
       msg = self.dbc[0].msgs[i]

can/parser.py

@@ -1,2 +1,2 @@
-from opendbc.can.parser_pyx import CANParser  # pylint: disable=no-name-in-module, import-error
-assert CANParser
+from opendbc.can.parser_pyx import CANParser, CANDefine  # pylint: disable=no-name-in-module, import-error
+assert CANParser, CANDefine

can/parser_pyx.pyx

@@ -17,7 +17,6 @@ from collections import defaultdict
 
 cdef int CAN_INVALID_CNT = 5
 
-
 cdef class CANParser:
   cdef:
     cpp_CANParser *can
@@ -37,10 +36,11 @@ cdef class CANParser:
   def __init__(self, dbc_name, signals, checks=None, bus=0):
     if checks is None:
       checks = []
-
     self.can_valid = True
     self.dbc_name = dbc_name
     self.dbc = dbc_lookup(dbc_name)
+    if not self.dbc:
+      raise RuntimeError("Can't lookup" + dbc_name)
     self.vl = {}
     self.ts = {}
 
@@ -148,7 +148,9 @@ cdef class CANDefine():
   def __init__(self, dbc_name):
     self.dbc_name = dbc_name
     self.dbc = dbc_lookup(dbc_name)
-
+    if not self.dbc:
+      raise RuntimeError("Can't lookup" + dbc_name)
+      
     num_vals = self.dbc[0].num_vals
 
     address_to_msg_name = {}

can/tests/test_dbc_exceptions.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+import unittest
+
+from opendbc.can.parser import CANParser, CANDefine
+from opendbc.can.packer import CANPacker
+
+class TestCanParserPackerExceptions(unittest.TestCase):
+  def test_civic_exceptions(self):
+    dbc_file = "honda_civic_touring_2016_can_generated"
+    dbc_invalid = dbc_file + "abcdef"
+    signals = [
+      ("STEER_TORQUE", "STEERING_CONTROL", 0),
+      ("STEER_TORQUE_REQUEST", "STEERING_CONTROL", 0),
+    ]
+    checks = []
+    with self.assertRaises(RuntimeError):
+      CANParser(dbc_invalid, signals, checks, 0)
+    with self.assertRaises(RuntimeError):
+      CANPacker(dbc_invalid)
+    with self.assertRaises(RuntimeError):
+      CANDefine(dbc_invalid)
+
+    # Everything is supposed to work below
+    CANParser(dbc_file, signals, checks, 0)
+    CANPacker(dbc_file)
+    CANDefine(dbc_file)
+
+
+if __name__ == "__main__":
+  unittest.main()