refactor: split in smaller functions

add protocol

app/pass_gen.py

@@ -1,17 +1,34 @@
-import string
 import random
+import string
+from typing import Protocol
 
 
 def generate_password(seed: int, length: int = 8, symbols: bool = False) -> str:
+    characters = _build_characters(symbols)
+
+    random_generator = _new_random_generator(seed)
+
+    return "".join(random_generator.sample(characters, length))
+
+
+class RandomSampler(Protocol):
+    def sample(self, population: str, k: int) -> list[str]:
+        ...  # pragma nocover
+
+
+def _new_random_generator(seed: int) -> RandomSampler:
+    return random.Random(seed)
+
+
+def _build_characters(symbols: bool) -> str:
     lowercase = string.ascii_lowercase
     uppercase = string.ascii_uppercase
     digits = string.digits
     punctuation = string.punctuation
 
-    letters = lowercase + uppercase + digits
+    characters = lowercase + uppercase + digits
+
     if symbols:
-        letters += punctuation
+        characters += punctuation
 
-    random_generator = random.Random(seed)
-
-    return "".join(random_generator.sample(letters, length))
+    return characters