Changes:

- remove underscore
- future proof hashed migrations

edgy/cli/templates/default/script.py.mako

@@ -5,9 +5,12 @@ Revises: ${down_revision | comma,n}
 Create Date: ${create_date}
 
 """
+<%
+    from edgy.utils.hashing import hash_to_identifier, hash_to_identifier_as_string
+%>
+from __future__ import annotations
 from alembic import op
 import sqlalchemy as sa
-from edgy.utils.hashing import hash_to_identifier
 ${imports if imports else ""}
 
 # revision identifiers, used by Alembic.
@@ -16,21 +19,24 @@ down_revision = ${repr(down_revision)}
 branch_labels = ${repr(branch_labels)}
 depends_on = ${repr(depends_on)}
 
+${hash_to_identifier_as_string}
+
 def upgrade(engine_name: str = "") -> None:
-    fn = globals().get(f"upgrade_{hash_to_identifier(engine_name)}")
+    # hash_to_identifier adds already an "_"
+    fn = globals().get(f"upgrade{hash_to_identifier(engine_name)}")
     if fn is not None:
         fn()
 
 
 def downgrade(engine_name: str = "") -> None:
-    fn = globals().get(f"downgrade_{hash_to_identifier(engine_name)}")
+    # hash_to_identifier adds already an "_"
+    fn = globals().get(f"downgrade{hash_to_identifier(engine_name)}")
     if fn is not None:
         fn()
 
 
 <%
     from edgy import monkay
-    from edgy.utils.hashing import hash_to_identifier
     db_names = monkay.settings.migrate_databases
 %>
 
@@ -39,13 +45,13 @@ def downgrade(engine_name: str = "") -> None:
 
 % for db_name in db_names:
 
-def ${f"upgrade_{hash_to_identifier(db_name or '')}"}():
+def ${f"upgrade{hash_to_identifier(db_name or '')}"}():
     # Migration of:
     # ${db_name or 'main database'}
     ${context.get(f"{db_name or ''}_upgrades", "pass")}
 
 
-def ${f"downgrade_{hash_to_identifier(db_name or '')}"}():
+def ${f"downgrade{hash_to_identifier(db_name or '')}"}():
     # Migration of:
     # ${db_name or 'main database'}
     ${context.get(f"{db_name or ''}_downgrades", "pass")}

edgy/cli/templates/plain/script.py.mako

@@ -5,6 +5,7 @@ Revises: ${down_revision | comma,n}
 Create Date: ${create_date}
 
 """
+from __future__ import annotations
 from alembic import op
 import sqlalchemy as sa
 ${imports if imports else ""}

edgy/cli/templates/url/script.py.mako

@@ -5,11 +5,14 @@ Revises: ${down_revision | comma,n}
 Create Date: ${create_date}
 
 """
+<%
+    from edgy.utils.hashing import hash_to_identifier, hash_to_identifier_as_string
+%>
+from __future__ import annotations
 from typing import TYPE_CHECKING, Optional
 
 from alembic import op
 import sqlalchemy as sa
-from edgy.utils.hashing import hash_to_identifier
 ${imports if imports else ""}
 
 if TYPE_CHECKING:
@@ -21,16 +24,22 @@ down_revision = ${repr(down_revision)}
 branch_labels = ${repr(branch_labels)}
 depends_on = ${repr(depends_on)}
 
+
+${hash_to_identifier_as_string}
+
+
 def upgrade(url: Optional["DatabaseURL"] = None) -> None:
     urlstring = "" if url is None else f"{url.username}:{url.netloc}"
-    fn = globals().get(f"upgrade_{hash_to_identifier(urlstring)}")
+    # hash_to_identifier adds already an "_"
+    fn = globals().get(f"upgrade{hash_to_identifier(urlstring)}")
     if fn is not None:
         fn()
 
 
 def downgrade(url: Optional["DatabaseURL"] = None) -> None:
     urlstring = "" if url is None else f"{url.username}:{url.netloc}"
-    fn = globals().get(f"downgrade_{hash_to_identifier(urlstring)}")
+    # hash_to_identifier adds already an "_"
+    fn = globals().get(f"downgrade{hash_to_identifier(urlstring)}")
     if fn is not None:
         fn()
 
@@ -53,13 +62,13 @@ def downgrade(url: Optional["DatabaseURL"] = None) -> None:
 
 % for db_name in db_names:
 
-def ${f"upgrade_{hash_to_identifier(url_for_name(db_name))}"}():
+def ${f"upgrade{hash_to_identifier(url_for_name(db_name))}"}():
     # Migration of:
     # ${url_for_name(db_name)} (${db_name or 'main database'})
     ${context.get(f"{db_name or ''}_upgrades", "pass")}
 
 
-def ${f"downgrade_{hash_to_identifier(url_for_name(db_name))}"}():
+def ${f"downgrade{hash_to_identifier(url_for_name(db_name))}"}():
     # Migration of:
     # ${url_for_name(db_name)} (${db_name or 'main database'})
     ${context.get(f"{db_name or ''}_downgrades", "pass")}

edgy/utils/hashing.py

@@ -1,9 +1,10 @@
+from __future__ import annotations
+
 from base64 import b32encode
 from hashlib import blake2b
-from typing import Union
 
 
-def hash_to_identifier(key: Union[str, bytes]) -> str:
+def hash_to_identifier(key: str | bytes) -> str:
     """
     A generic hasher for keys, which output stays a valid name for python
     and other languages.
@@ -16,4 +17,17 @@ def hash_to_identifier(key: Union[str, bytes]) -> str:
     if isinstance(key, str):
         key = key.encode()
     # prefix with _ for preventing a name starting with a number
+    # Note: the prefixing with underscore is expected by migrations
+    return f"_{b32encode(blake2b(key, digest_size=16).digest()).decode().rstrip('=')}"
+
+
+# for migrations
+# needs however either python 3.10 or from __future__ import annotations
+hash_to_identifier_as_string: str = """
+def hash_to_identifier(key: str | bytes) -> str:
+    from base64 import b32encode
+    from hashlib import blake2b
+    if isinstance(key, str):
+        key = key.encode()
     return f"_{b32encode(blake2b(key, digest_size=16).digest()).decode().rstrip('=')}"
+"""