This issue is in three parts:

no-transform directive always returns None

This directive has no arguments (either in current RFC 9111 or older RFC 2616)

from werkzeug.http import parse_cache_control_header

cc = parse_cache_control_header("no-transform")
print(f"{cc.no_transform=}")

Output:

cc.no_transform=None

Expected: boolean based on presence

min-fresh directive returns "*" if missing required argument

from werkzeug.http import parse_cache_control_header

cc = parse_cache_control_header("min-fresh")
print(f"{cc.min_fresh=}")

Output:

cc.min_fresh='*'

Expected: None since the argument is required and "*" doesn't have a semantic meaning for this directive.

type stubs are incorrect

• no_cache returns str not bool.
• bool properties never return None
• max_stale returns "*" in addition to int.
• RequestCacheControl immutability is not reflected.

Environment:

• Python version: N/A
• Werkzeug version: 3.0.2