feat: Allow compatibility with other ShortUUID libraries (#104) (#107)

* refactor: Add should_sort arg to set_alphabet

* feat: add should_sort kwarg to Django Field

* refactor: changes should_sort kwarg name and default value

* docs: Update README.md

README.md

@@ -90,6 +90,16 @@ consistency:
 '0123abcdefgh'
 ```
 
+You can prevent the alphabet from being sorted by passing the `dont_sort_alphabet` 
+keyword argument to `set_alphabet()`. This option ensures compatibility with different 
+implementations of ShortUUID:
+
+```python
+>>> shortuuid.set_alphabet("aaaaabcdefgh1230123", dont_sort_alphabet=True)
+>>> shortuuid.get_alphabet()
+'abcdefgh1230'
+```
+
 If the default 22 digits are too long for you, you can get shorter IDs by just
 truncating the string to the desired length. The IDs won't be universally unique any
 longer, but the probability of a collision will still be very low.
@@ -168,6 +178,7 @@ class MyModel(models.Model):
         max_length=40,
         prefix="id_",
         alphabet="abcdefg1234",
+        dont_sort_alphabet=False
         primary_key=True,
     )
 

shortuuid/django_fields.py

@@ -14,6 +14,7 @@ class ShortUUIDField(models.CharField):
     def __init__(self, *args: Any, **kwargs: Any) -> None:
         self.length: int = kwargs.pop("length", 22)  # type: ignore
         self.prefix: str = kwargs.pop("prefix", "")  # type: ignore
+        self.dont_sort_alphabet: bool = kwargs.pop("dont_sort_alphabet", False)  # type: ignore
 
         if "max_length" not in kwargs:
             # If `max_length` was not specified, set it here.
@@ -26,7 +27,7 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
 
     def _generate_uuid(self) -> str:
         """Generate a short random string."""
-        return self.prefix + ShortUUID(alphabet=self.alphabet).random(
+        return self.prefix + ShortUUID(alphabet=self.alphabet, dont_sort_alphabet=self.dont_sort_alphabet).random(
             length=self.length
         )
 

shortuuid/main.py

@@ -40,11 +40,11 @@ def string_to_int(string: str, alphabet: List[str]) -> int:
 
 
 class ShortUUID(object):
-    def __init__(self, alphabet: Optional[str] = None) -> None:
+    def __init__(self, alphabet: Optional[str] = None, dont_sort_alphabet: Optional[bool] = False) -> None:
         if alphabet is None:
             alphabet = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ" "abcdefghijkmnopqrstuvwxyz"
 
-        self.set_alphabet(alphabet)
+        self.set_alphabet(alphabet, dont_sort_alphabet=dont_sort_alphabet)
 
     @property
     def _length(self) -> int:
@@ -110,11 +110,11 @@ def get_alphabet(self) -> str:
         """Return the current alphabet used for new UUIDs."""
         return "".join(self._alphabet)
 
-    def set_alphabet(self, alphabet: str) -> None:
+    def set_alphabet(self, alphabet: str, dont_sort_alphabet: bool=False) -> None:
         """Set the alphabet to be used for new UUIDs."""
         # Turn the alphabet into a set and sort it to prevent duplicates
         # and ensure reproducibility.
-        new_alphabet = list(sorted(set(alphabet)))
+        new_alphabet = list(dict.fromkeys(alphabet)) if dont_sort_alphabet else list(sorted(set(alphabet)))
         if len(new_alphabet) > 1:
             self._alphabet = new_alphabet
             self._alpha_len = len(self._alphabet)

shortuuid/test_shortuuid.py

@@ -115,6 +115,29 @@ def test_alphabet(self):
         self.assertRaises(ValueError, su1.set_alphabet, "1")
         self.assertRaises(ValueError, su1.set_alphabet, "1111111")
 
+    def test_unsorted_alphabet(self):
+        alphabet = "123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ"
+
+        su1 = ShortUUID(alphabet, dont_sort_alphabet=True)
+        su2 = ShortUUID()
+
+        self.assertEqual(alphabet, su1.get_alphabet())
+
+        su2.set_alphabet(alphabet, dont_sort_alphabet=True)
+        self.assertEqual(alphabet, su2.get_alphabet())
+
+        su2.set_alphabet(alphabet + "123abc", dont_sort_alphabet=True)
+        self.assertEqual(alphabet, su2.get_alphabet())
+
+        u = uuid4()
+        self.assertEqual(u, su1.decode(su1.encode(u)))
+
+        u = su1.uuid()
+        self.assertEqual(u, su1.encode(su1.decode(u)))
+
+        self.assertRaises(ValueError, su1.set_alphabet, "1")
+        self.assertRaises(ValueError, su1.set_alphabet, "1111111")
+
     def test_encoded_length(self):
         su1 = ShortUUID()
         self.assertEqual(su1.encoded_length(), 22)