Open cache strategy API up for including user in cache key

... and possibly by extension also the `policy_class`.

lib/pundit.rb

@@ -10,7 +10,7 @@
 require "pundit/authorization"
 require "pundit/context"
 require "pundit/cache_store/null_store"
-require "pundit/cache_store/hash_store"
+require "pundit/cache_store/legacy_store"
 
 # @api private
 # To avoid name clashes with common Error naming when mixing in Pundit,

lib/pundit/authorization.rb

@@ -19,7 +19,7 @@ module Authorization
     def pundit
       @pundit ||= Pundit::Context.new(
         user: pundit_user,
-        policy_cache: Pundit::CacheStore::HashStore.new(policies)
+        policy_cache: Pundit::CacheStore::LegacyStore.new(policies)
       )
     end
 

lib/pundit/cache_store/hash_store.rb → lib/pundit/cache_store/legacy_store.rb

@@ -3,13 +3,14 @@
 module Pundit
   module CacheStore
     # @api private
-    class HashStore
+    class LegacyStore
       def initialize(hash = {})
         @store = hash
       end
 
-      def fetch(key)
-        @store[key] ||= yield
+      def fetch(user:, record:)
+        _ = user
+        @store[record] ||= yield
       end
     end
   end

lib/pundit/context.rb

@@ -84,7 +84,7 @@ def policy_scope!(scope)
     # @raise [InvalidConstructorError] if the policy constructor called incorrectly
     # @return [Object, nil] instance of policy class with query methods
     def policy(record)
-      cached_policy(record, &:policy)
+      cached_find(record, &:policy)
     end
 
     # Retrieves the policy for the given record. Raises if not found.
@@ -96,20 +96,22 @@ def policy(record)
     # @raise [InvalidConstructorError] if the policy constructor called incorrectly
     # @return [Object] instance of policy class with query methods
     def policy!(record)
-      cached_policy(record, &:policy!)
+      cached_find(record, &:policy!)
     end
 
     private
 
-    def cached_policy(record)
-      policy_cache.fetch(record) do
-        policy = yield policy_finder(record)
-        next unless policy
+    def cached_find(record)
+      policy_cache.fetch(user: user, record: record) do
+        klass = yield policy_finder(record)
+        next unless klass
+
+        model = pundit_model(record)
 
         begin
-          policy.new(user, pundit_model(record))
+          klass.new(user, model)
         rescue ArgumentError
-          raise InvalidConstructorError, "Invalid #<#{policy}> constructor is called"
+          raise InvalidConstructorError, "Invalid #<#{klass}> constructor is called"
         end
       end
     end