Add update block ability with conditions

app/abilities/ability.rb

@@ -60,7 +60,10 @@ class Ability
           can [:index, :show, :resolve, :ignore, :reopen], Issue
           can :create, IssueComment
           can [:new, :create, :edit, :update, :destroy], Redaction
-          can [:new, :edit, :create, :update, :revoke, :revoke_all], UserBlock
+          can [:new, :create, :revoke, :revoke_all], UserBlock
+          can :update, UserBlock, :creator => user
+          can :update, UserBlock, :revoker => user
+          can :update, UserBlock, :active? => true
         end
 
         if user.administrator?

test/abilities/abilities_test.rb

@@ -95,6 +95,53 @@ class ModeratorAbilityTest < AbilityTest
       assert ability.can?(action, DiaryComment), "should be able to #{action} DiaryComment"
     end
   end
+
+  test "Active block update permissions" do
+    creator_user = create(:moderator_user)
+    other_moderator_user = create(:moderator_user)
+    block = create(:user_block, :creator => creator_user)
+
+    creator_ability = Ability.new creator_user
+    assert creator_ability.can?(:edit, block)
+    assert creator_ability.can?(:update, block)
+
+    other_moderator_ability = Ability.new other_moderator_user
+    assert other_moderator_ability.can?(:edit, block)
+    assert other_moderator_ability.can?(:update, block)
+  end
+
+  test "Expired block update permissions" do
+    creator_user = create(:moderator_user)
+    other_moderator_user = create(:moderator_user)
+    block = create(:user_block, :expired, :creator => creator_user)
+
+    creator_ability = Ability.new creator_user
+    assert creator_ability.can?(:edit, block)
+    assert creator_ability.can?(:update, block)
+
+    other_moderator_ability = Ability.new other_moderator_user
+    assert other_moderator_ability.cannot?(:edit, block)
+    assert other_moderator_ability.cannot?(:update, block)
+  end
+
+  test "Revoked block update permissions" do
+    creator_user = create(:moderator_user)
+    revoker_user = create(:moderator_user)
+    other_moderator_user = create(:moderator_user)
+    block = create(:user_block, :revoked, :creator => creator_user, :revoker => revoker_user)
+
+    creator_ability = Ability.new creator_user
+    assert creator_ability.can?(:edit, block)
+    assert creator_ability.can?(:update, block)
+
+    revoker_ability = Ability.new revoker_user
+    assert revoker_ability.can?(:edit, block)
+    assert revoker_ability.can?(:update, block)
+
+    other_moderator_ability = Ability.new other_moderator_user
+    assert other_moderator_ability.cannot?(:edit, block)
+    assert other_moderator_ability.cannot?(:update, block)
+  end
 end
 
 class AdministratorAbilityTest < AbilityTest