tests: fix unit tests.

* Move old post archive tests to post version tests.

* Fix pool tests that assumed that multiple edits by the same user
  weren't merged.

* Fix references to `is_active` and `notes` on artist model.

test/unit/post_version_test.rb

@@ -65,12 +65,25 @@ class PostVersionTest < ActiveSupport::TestCase
       end
     end
 
+    context "that is tagged with a pool:<name> metatag" do
+      setup do
+        @pool = create(:pool)
+        @post = create(:post, tag_string: "tagme pool:#{@pool.id}")
+      end
+
+      should "create a version" do
+        assert_equal("tagme", @post.tag_string)
+        assert_equal("pool:#{@pool.id}", @post.pool_string)
+
+        assert_equal(1, @post.versions.size)
+        assert_equal("tagme", @post.versions.last.tags)
+      end
+    end
+
     context "that has been updated" do
       setup do
         PostVersion.sqs_service.stubs(:merge?).returns(false)
-        travel_to(1.minute.ago) do
-          @post = FactoryBot.create(:post, :tag_string => "aaa bbb ccc", :rating => "q", :source => "xyz")
-        end
+        @post = create(:post, created_at: 1.minute.ago, tag_string: "aaa bbb ccc", rating: "q", source: "xyz")
         @post.update(tag_string: "bbb ccc xxx", source: "")
       end
 
@@ -82,6 +95,57 @@ class PostVersionTest < ActiveSupport::TestCase
         assert_equal("", @version.source)
         assert_nil(@version.parent_id)
       end
+
+      should "not create a version if updating the post fails" do
+        @post.stubs(:set_tag_counts).raises(NotImplementedError)
+
+        assert_equal(2, @post.versions.size)
+        assert_raise(NotImplementedError) { @post.update(rating: "s") }
+        assert_equal(2, @post.versions.size)
+      end
+
+      should "should create a version if the rating changes" do
+        assert_difference("@post.versions.size", 1) do
+          @post.update(rating: "s")
+          assert_equal("s", @post.versions.max_by(&:id).rating)
+        end
+      end
+
+      should "should create a version if the source changes" do
+        assert_difference("@post.versions.size", 1) do
+          @post.update(source: "blah")
+          assert_equal("blah", @post.versions.max_by(&:id).source)
+        end
+      end
+
+      should "should create a version if the parent changes" do
+        assert_difference("@post.versions.size", 1) do
+          @parent = create(:post)
+          @post.update(parent_id: @parent.id)
+          assert_equal(@parent.id, @post.versions.max_by(&:id).parent_id)
+        end
+      end
+
+      should "should create a version if the tags change" do
+        assert_difference("@post.versions.size", 1) do
+          @post.update(tag_string: "blah")
+          assert_equal("blah", @post.versions.max_by(&:id).tags)
+        end
+      end
+    end
+
+    context "#undo" do
+      setup do
+        PostVersion.sqs_service.stubs(:merge?).returns(false)
+        @post = create(:post, tag_string: "1")
+        @post.update(tag_string: "1 2")
+        @post.update(tag_string: "2 3")
+      end
+
+      should "undo the changes" do
+        @post.versions[1].undo!
+        assert_equal("3", @post.reload.tag_string)
+      end
     end
   end
 end