Fix: Pundit.authorize when passing a custom cache

We accidentally broke this interface when the internal cache interface changed a while back.

According to documentation, and how it worked in the past, it should accept a Hash-like interface.

.rubocop.yml

@@ -39,6 +39,9 @@ Layout/CaseIndentation:
 Layout/FirstArrayElementIndentation:
   EnforcedStyle: consistent
 
+Layout/FirstHashElementIndentation:
+  EnforcedStyle: consistent
+
 Layout/EndAlignment:
   EnforcedStyleAlignWith: variable
 

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Fixed
+
+- Using a hash as custom cache in `Pundit.authorize` now works as documented. (#838)
+
 ## 2.4.0 (2024-08-26)
 
 ## Changed

lib/pundit.rb

@@ -74,7 +74,8 @@ class << self
     # @see Pundit::Context#authorize
     def authorize(user, record, query, policy_class: nil, cache: nil)
       context = if cache
-        Context.new(user: user, policy_cache: cache)
+        policy_cache = CacheStore::LegacyStore.new(cache)
+        Context.new(user: user, policy_cache: policy_cache)
       else
         Context.new(user: user)
       end

spec/pundit_spec.rb

@@ -125,6 +125,18 @@
         expect(Pundit.authorize(user, [:project, comment], :create?, policy_class: PublicationPolicy)).to be_truthy
       end
     end
+
+    context "when passed an explicit cache" do
+      it "uses the hash assignment interface on the cache" do
+        custom_cache = CustomCache.new
+
+        Pundit.authorize(user, post, :update?, cache: custom_cache)
+
+        expect(custom_cache.to_h).to match({
+          post => kind_of(PostPolicy)
+        })
+      end
+    end
   end
 
   describe ".policy_scope" do

spec/support/lib/custom_cache.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class CustomCache
+  def initialize
+    @store = {}
+  end
+
+  def to_h
+    @store
+  end
+
+  def [](key)
+    @store[key]
+  end
+
+  def []=(key, value)
+    @store[key] = value
+  end
+end