3 files changed, 73 insertions, 3 deletions

diff --git a/test/controllers/admin_controller_test.rb b/test/controllers/admin_controller_test.rb
index 9bbf29b..d6005ba 100644
--- a/test/controllers/admin_controller_test.rb
+++ b/test/controllers/admin_controller_test.rb
@@ -1,8 +1,17 @@
 require 'test_helper'
 
 class AdminControllerTest < ActionController::TestCase
-  # Replace this with your real tests.
-  test "the truth" do
-    assert true
+  test "current drafts includes nodes with only an autosave" do
+    node = Node.root.children.create!(:slug => "admin_autosave_only")
+    node.lock_for_editing!(User.find_by_login("aaron"))
+    node.autosave!({title: "in progress"}, User.find_by_login("aaron"))
+    node.save_draft!(User.find_by_login("aaron"))
+    node.publish_draft!
+    node.lock_for_editing!(User.find_by_login("aaron"))
+    node.autosave!({title: "editing again"}, User.find_by_login("aaron"))
+
+    login_as :quentin
+    get :index
+    assert_includes assigns(:drafts), node
   end
 end
diff --git a/test/controllers/revisions_controller_test.rb b/test/controllers/revisions_controller_test.rb
index caca6bf..162e6f1 100644
--- a/test/controllers/revisions_controller_test.rb
+++ b/test/controllers/revisions_controller_test.rb
@@ -100,4 +100,43 @@ class RevisionsControllerTest < ActionController::TestCase
     assert_response :success
     assert_select ".diff_column", 2
   end
+
+  test "diffing head against draft by name" do
+    login_as :quentin
+    @node.find_or_create_draft(@user)
+    @node.draft.update(:body => "draft body")
+
+    post(:diff, params: { :node_id => @node.id, :start_revision => "head", :end_revision => "draft" })
+    assert_response :success
+  end
+
+  test "diffing a layer pair that no longer exists redirects with a flash" do
+    login_as :quentin
+    post(:diff, params: { :node_id => @node.id, :start_revision => "draft", :end_revision => "autosave" })
+    assert_redirected_to node_path(@node)
+    assert flash[:error].present?
+  end
+
+  test "diffing by name shows a clear comparison label instead of a misleading revision picker" do
+    login_as :quentin
+    @node.find_or_create_draft(@user)
+
+    post(:diff, params: { :node_id => @node.id, :start_revision => "head", :end_revision => "draft" })
+    assert_response :success
+    assert_select "strong", "Head"
+    assert_select "strong", "Draft"
+    assert_select "select[name=?]", "start_revision", :count => 0
+  end
+
+  test "pair-switcher buttons carry their params as real hidden fields, not a query string" do
+    login_as :quentin
+    @node.find_or_create_draft(@user)
+    @node.lock_for_editing!(@user)
+    @node.autosave!({ :body => "unsaved" }, @user)
+
+    post(:diff, params: { :node_id => @node.id, :start_revision => "head", :end_revision => "draft" })
+    assert_response :success
+    assert_select "form.computation input[type=hidden][name=start_revision]"
+    assert_select "form.computation input[type=hidden][name=end_revision]"
+  end
 end
diff --git a/test/models/node_test.rb b/test/models/node_test.rb
index 2138c19..9e71dec 100644
--- a/test/models/node_test.rb
+++ b/test/models/node_test.rb
@@ -473,4 +473,26 @@ class NodeTest < ActiveSupport::TestCase
       node.publish_draft!
     end
   end
+
+  test "available_layer_pairs matches the six-state table" do
+    node = Node.root.children.create!(:slug => "layer_pairs_test")
+    user = @user1 || User.find_by_login("aaron")
+
+    assert_equal [[:draft, :autosave]], (node.lock_for_editing!(user); node.autosave!({title: "v1"}, user); node.available_layer_pairs) # state F
+
+    node.save_draft!(user)
+    node.publish_draft!
+    assert_equal [], node.available_layer_pairs # state A
+
+    node.lock_for_editing!(user)
+    node.autosave!({title: "v2"}, user)
+    assert_equal [[:head, :autosave]], node.available_layer_pairs # state B
+
+    node.save_draft!(user)
+    assert_equal [[:head, :draft]], node.available_layer_pairs # state C
+
+    node.lock_for_editing!(user)
+    node.autosave!({title: "v3"}, user)
+    assert_equal [[:head, :draft], [:draft, :autosave]], node.available_layer_pairs # state D
+  end
 end