crates/policy had zero property tests: the wildcard Action/Resource matching
and Deny-first evaluation in Policy::is_allowed — the algebra authorization
safety rests on — were guarded only by example-based tests.
Add crates/policy/tests/policy_eval_proptest.rs with three generated-input
invariants (pure evaluation, no IO or global state, parallel-safe):
- explicit_deny_anywhere_denies: a Deny matching the request denies it no
matter how many broad Allow statements co-exist or at which index the Deny
sits; a built-in sanity assertion first proves the Allows alone would permit,
so the Deny is what flips the decision.
- wildcard_superset_implies_concrete_match: any request allowed by an
exact-action/exact-resource policy is also allowed after widening to s3:* on
bucket/* and to * on arn:aws:s3:::*, checked both on the built grant and on
random probe requests (implication form).
- empty_policy_denies_everything: a statement-less policy and Policy::default()
deny every non-owner request.
Statements are built from JSON exactly as production policies arrive via
PutPolicy. Generated names avoid wildcard metacharacters so the only wildcards
in play are the ones the properties introduce deliberately. proptest joins
crates/policy dev-deps following the filemeta/ecstore precedent.
Refs: backlog#1151 (sec-9)
Zhengchao An