adding basic tests for smbus

tests/mock_smbus2.py

@@ -0,0 +1,24 @@
+from smbus2 import i2c_msg
+
+from .context import sgp30
+
+def add_crc(l):
+    return l + [sgp30.Crc8().hash(l)]
+
+answers = {
+    (0x36, 0x82): add_crc([0,0]) ,#GET_SERIAL
+    (0x20, 0x15): add_crc([0,0]) ,#GET_FEATURES
+    (0x20, 0x03): None ,#IAQ_INIT
+    (0x20, 0x08): [1, 144, 76, 0, 6, 39] ,#IAQ_MEASURE
+    (0x20, 0x32): add_crc([0xD4,0x00]),#IAQ_SELFTEST
+    (0x20, 0x15): add_crc([0x00,0x00])*2 ,#GET_BASELINE  Invalid, should be more realistic data..
+    (0x20, 0x1e): None,#SET_BASELINE
+}
+class MockSMBus:
+    def __init__(s):
+        s.status=None
+
+    def i2c_rdwr(s,*msgs):
+            print(i2c_msg.read)
+        
+    

tests/test_sgp.py

@@ -0,0 +1,11 @@
+from .context import sgp30
+
+from mock_smbus2 import MockSMBus
+import unittest
+class BasicTestSuite(unittest.TestCase):
+    """Basic test cases."""
+    def setUp(self):
+        self.bus = MockSMBus()
+    def test_init(self):
+        b=sgp30.sgp30.Sgp30(self.bus)
+        b.init_sgp()