fix: Fix errors when modifying register attributes when unsaved

lib/paneron/register/raw/register.rb

@@ -402,10 +402,14 @@ def data_set_path(data_set_name)
         end
 
         def metadata
-          @metadata ||= YAML.safe_load_file(
-            register_yaml_path,
-            permitted_classes: [Time, Date, DateTime],
-          )
+          @metadata ||= begin
+            YAML.safe_load_file(
+              register_yaml_path,
+              permitted_classes: [Time, Date, DateTime],
+            )
+          rescue Errno::ENOENT
+            self.class.metadata_template
+          end
         end
 
         def metadata=(metadata)

spec/raw_register_spec.rb

@@ -471,18 +471,30 @@
   end
 
   describe "#title=" do
-    it "updates the metadata title" do
-      expect do
-        raw_register.title = "new title"
-      end.to change { raw_register.metadata["title"] }.from("register").to("new title")
+    shared_examples_for "changes title" do |old_title|
+      it "updates the metadata title" do
+        expect do
+          raw_register.title = "new title"
+        end.to change { raw_register.metadata["title"] }.from(old_title).to("new title")
 
-      expect do
-        raw_register.title = "new title"
-      end.to_not(change { raw_register.metadata["title"] })
+        expect do
+          raw_register.title = "new title"
+        end.to_not(change { raw_register.metadata["title"] })
 
-      expect do
-        raw_register.title = "new title 2"
-      end.to change { raw_register.title }.from("new title").to("new title 2")
+        expect do
+          raw_register.title = "new title 2"
+        end.to change { raw_register.title }.from("new title").to("new title 2")
+      end
+    end
+
+    it_behaves_like "changes title", "register"
+
+    describe "for an unsaved register" do
+      let(:raw_register) do
+        described_class.new("./another/new/register")
+      end
+
+      it_behaves_like "changes title", ""
     end
   end
 end