Reduce duplication in Config#enabled

lib/paper_trail/config.rb

@@ -38,10 +38,10 @@ module PaperTrail
     end
     alias_method :track_associations?, :track_associations
 
-    # Indicates whether PaperTrail is on or off.
+    # Indicates whether PaperTrail is on or off. Default: true.
     def enabled
-      PaperTrail.paper_trail_store[:paper_trail_enabled].nil? ||
-        PaperTrail.paper_trail_store[:paper_trail_enabled]
+      value = PaperTrail.paper_trail_store.fetch(:paper_trail_enabled, true)
+      value.nil? ? true : value
     end
 
     def enabled= enable

spec/paper_trail/config_spec.rb

@@ -0,0 +1,52 @@
+require "rails_helper"
+
+module PaperTrail
+  RSpec.describe Config do
+    describe ".instance" do
+      it "returns the singleton instance" do
+        expect { described_class.instance }.to_not raise_error
+      end
+    end
+
+    describe ".new" do
+      it "raises NoMethodError" do
+        expect { described_class.new }.to raise_error(NoMethodError)
+      end
+    end
+
+    describe "#enabled" do
+      context "when paper_trail_enabled is true" do
+        it "returns true" do
+          store = double
+          allow(store).to receive(:fetch).
+            with(:paper_trail_enabled, true).
+            and_return(true)
+          allow(PaperTrail).to receive(:paper_trail_store).and_return(store)
+          expect(described_class.instance.enabled).to eq(true)
+        end
+      end
+
+      context "when paper_trail_enabled is false" do
+        it "returns false" do
+          store = double
+          allow(store).to receive(:fetch).
+            with(:paper_trail_enabled, true).
+            and_return(false)
+          allow(PaperTrail).to receive(:paper_trail_store).and_return(store)
+          expect(described_class.instance.enabled).to eq(false)
+        end
+      end
+
+      context "when paper_trail_enabled is nil" do
+        it "returns true" do
+          store = double
+          allow(store).to receive(:fetch).
+            with(:paper_trail_enabled, true).
+            and_return(nil)
+          allow(PaperTrail).to receive(:paper_trail_store).and_return(store)
+          expect(described_class.instance.enabled).to eq(true)
+        end
+      end
+    end
+  end
+end