fix(system): add check of component name and set default load phase i…

…n change_comp()

src/sysloss/system.py

@@ -222,6 +222,13 @@ def _chk_parent(self, parent: str):
 
         return True
 
+    def _chk_comp(self, comp: str):
+        """Check if component exists"""
+        if not comp in self._g.attrs["nodes"].keys():
+            raise ValueError('Component name "{}" not found!'.format(comp))
+
+        return True
+
     def _chk_name(self, name: str):
         """Check if component name is valid"""
         # check if name exists
@@ -371,13 +378,16 @@ def change_comp(self, name: str, *, comp):
         ------
         ValueError
             If trying to change a `source` component to a different type, or
+            if the target component does not exist or
             if the parent does not accept a connection to the new component.
 
         Examples
         --------
         >>> sys.change_comp("Buck", comp=LinReg("LDO", vo=1.8))
 
         """
+        # check that component exists
+        self._chk_comp(name)
         # if component name changes, check that it is unique
         if name != comp._params["name"]:
             self._chk_name(comp._params["name"])
@@ -401,6 +411,9 @@ def change_comp(self, name: str, *, comp):
         # replace node name in graph dict
         del [self._g.attrs["nodes"][name]]
         self._g.attrs["nodes"][comp._params["name"]] = eidx
+        # delete old phase config and set new default
+        del [self._g.attrs["phase_conf"][name]]
+        self._g.attrs["phase_conf"][comp._params["name"]] = {}
 
     def del_comp(self, name: str, *, del_childs: bool = True):
         """Delete component.

tests/unit/test_system.py

@@ -203,11 +203,16 @@ def test_case10():
     """Change component"""
     case10 = System("Case10 system", Source("24V system", vo=24.0, rs=12e-3))
     case10.add_comp("24V system", comp=Converter("Buck", vo=3.3, eff=0.80))
+    case10.add_comp("Buck", comp=PLoad("Load", pwr=0.5))
     case10.change_comp("Buck", comp=LinReg("LDO", vo=3.3))
     with pytest.raises(ValueError):
         case10.change_comp("LDO", comp=Source("5V", vo=5.0))
     with pytest.raises(ValueError):
         case10.change_comp("24V system", comp=LinReg("LDO2", vo=3.3))
+    with pytest.raises(ValueError):
+        case10.change_comp("Non-exist", comp=Source("5V", vo=5.0))
+    df = case10.solve()
+    assert len(df) == 4, "Case10 parameters row count"
 
 
 def test_case11():