Prevent double entries in the corresponding dictionaries

libcobblersignatures/models/osbreed.py

@@ -9,7 +9,9 @@ class OsBreed:
     described in the JSON specification.
     """
 
-    def __init__(self, name):
+    def __init__(self, name: str):
+        if not isinstance(name, str):
+            raise TypeError("The name of an OsBreed must be of type str!")
         self._name = name
         self._osversions = collections.OrderedDict()
 
@@ -112,6 +114,8 @@ def osversion_add(self, name: str, version: Osversion):
         :raises ValueError: If the Name is not a ``str`` and/or the Version is not an ``Osversion``.
         """
         if isinstance(name, str) and isinstance(version, Osversion):
+            if name in self.osversions:
+                raise ValueError("The name \"%s\" already exists for the OsBreed \"%s\"!" % (name, self.name))
             self.osversions[name] = version
         else:
             raise ValueError("Name must be str and Version must be Osversion.")

libcobblersignatures/signatures.py

@@ -198,6 +198,8 @@ def addosbreed(self, name: str):
 
         :param name: The name of the new breed. Must not exist in the currently loaded models.
         """
+        if name in [x.name for x in self.osbreeds]:
+            raise ValueError("Breed \"%s\" already in the list of breeds!" % name)
         self.osbreeds.append(OsBreed(name))
 
     def addosversion(self, breedindex: int, versionname: str, versiondata):