add mapping policy

spec/policies/mapping_policy_spec.rb

@@ -3,5 +3,92 @@ require 'rails_helper'
 RSpec.describe MappingPolicy, type: :policy do
   subject { described_class }
 
-  pending 'Implement some mapping tests!'
+  context 'unauthenticated' do
+    context 'commons' do
+      let(:map) { create(:map, permission: :commons) }
+      let(:topic) { create(:topic, permission: :commons) }
+      let(:mapping) { create(:mapping, mappable: topic, map: map) }
+
+      permissions :show? do
+        it 'permits access' do
+          expect(subject).to permit(nil, mapping)
+        end
+      end
+      permissions :create?, :update?, :destroy? do
+        it 'denies access' do
+          expect(subject).to_not permit(nil, mapping)
+        end
+      end
+    end
+
+    context 'private' do
+      let(:map) { create(:map, permission: :private) }
+      let(:topic) { create(:topic, permission: :private) }
+      let(:mapping) { create(:mapping, mappable: topic, map: map) }
+
+      permissions :show?, :create?, :update?, :destroy? do
+        it 'denies access' do
+          expect(subject).to_not permit(nil, mapping)
+        end
+      end
+    end
+  end
+
+  #
+  # Now begin the logged-in tests
+  #
+
+  context 'logged in' do
+    let(:user) { create(:user) }
+
+    context 'commons' do
+      let(:owner) { create(:user) }
+      let(:topic) { create(:topic, permission: :commons, user: owner) }
+      let(:map) { create(:map, permission: :commons, user: owner) }
+      let(:mapping) { create(:mapping, mappable: topic, map: map) }
+
+      permissions :show?, :create?, :update?, :destroy? do
+        it 'permits access' do
+          expect(subject).to permit(user, mapping)
+        end
+      end
+    end
+
+    context 'public' do
+      let(:owner) { create(:user) }
+      let(:topic) { create(:topic, permission: :public, user: owner) }
+      let(:map) { create(:map, permission: :public, user: owner) }
+      let(:mapping) { create(:mapping, mappable: topic, map: map) }
+
+      permissions :show? do
+        it 'permits access' do
+          expect(subject).to permit(user, mapping)
+        end
+      end
+      permissions :create?, :update?, :destroy? do
+        it 'denies access' do
+          expect(subject).to_not permit(user, mapping)
+        end
+        it 'permits access to owner' do
+          expect(subject).to permit(owner, mapping)
+        end
+      end
+    end
+
+    context 'private' do
+      let(:owner) { create(:user) }
+      let(:topic) { create(:topic, permission: :private, user: owner) }
+      let(:map) { create(:map, permission: :public, user: owner) }
+      let(:mapping) { create(:mapping, mappable: topic, map: map) }
+
+      permissions :show?, :create?, :update?, :destroy? do
+        it 'denies access' do
+          expect(subject).to_not permit(user, mapping)
+        end
+        it 'permits access to owner' do
+          expect(subject).to permit(owner, mapping)
+        end
+      end
+    end
+  end
 end