Reorganize specs to make them easier to read

spec/pundit_spec.rb

@@ -43,15 +43,6 @@
       expect(Pundit.authorize(user, Post, :show?)).to eq(Post)
     end
 
-    it "can be given a different policy class" do
-      expect(Pundit.authorize(user, post, :create?, policy_class: PublicationPolicy)).to be_truthy
-    end
-
-    it "can be given a different policy class using namespaces" do
-      expect(PublicationPolicy).to receive(:new).with(user, comment).and_call_original
-      expect(Pundit.authorize(user, [:project, comment], :create?, policy_class: PublicationPolicy)).to be_truthy
-    end
-
     it "works with anonymous class policies" do
       expect(Pundit.authorize(user, article_tag, :show?)).to be_truthy
       expect { Pundit.authorize(user, article_tag, :destroy?) }.to raise_error(Pundit::NotAuthorizedError)
@@ -112,6 +103,29 @@
       end.to raise_error(Pundit::InvalidConstructorError, "Invalid #<WikiPolicy> constructor is called")
     end
 
+    context "when passed a policy class" do
+      it "uses the passed policy class" do
+        expect(Pundit.authorize(user, post, :create?, policy_class: PublicationPolicy)).to be_truthy
+      end
+
+      # This is documenting past behaviour.
+      it "doesn't cache the policy class" do
+        cache = {}
+
+        Pundit.authorize(user, post, :create?, policy_class: PublicationPolicy, cache: cache)
+        Pundit.authorize(user, post, :create?, policy_class: PublicationPolicy, cache: cache)
+
+        expect(PublicationPolicy.instances).to eq 2
+      end
+    end
+
+    context "when passed a policy class while simultaenously passing a namespace" do
+      it "uses the passed policy class" do
+        expect(PublicationPolicy).to receive(:new).with(user, comment).and_call_original
+        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