Test read_all throws exception when unavailable

Author: Gadgetoid

library/tests/test_setup.py

@@ -1,3 +1,6 @@
+import pytest
+
+
 def test_gas_setup(GPIO, smbus):
     from enviroplus import gas
     gas._is_setup = False
@@ -11,6 +14,9 @@ def test_gas_unavailable(GPIO, mocksmbus):
     gas._is_setup = False
     assert gas.available() == False
 
+    with pytest.raises(RuntimeError):
+        gas.read_all()
+
 
 def test_gas_available(GPIO, mocksmbus):
     from enviroplus import gas