FIX: saving preferences wasn't working (#93)

register_editable_user_custom_field is "singular" and only access one
"custom field" as a parameter.

the fix was to call register_editable_user_custom_field for each custom
fields this plugin uses.

also added a bunch of system specs to ensure the basics of the plugin
actually works.

Internal ref - t/161823

plugin.rb

@@ -29,7 +29,9 @@ after_initialize do
 
   add_to_serializer(:user, :see_signatures) { object.see_signatures }
 
-  register_editable_user_custom_field %i[see_signatures signature_url signature_raw]
+  register_editable_user_custom_field :see_signatures
+  register_editable_user_custom_field :signature_url
+  register_editable_user_custom_field :signature_raw
 
   allow_public_user_custom_field :signature_cooked
   allow_public_user_custom_field :signature_url

spec/system/image_signatures_spec.rb

@@ -0,0 +1,127 @@
+# frozen_string_literal: true
+
+RSpec.describe "Image signatures", type: :system do
+  fab!(:user)
+  fab!(:topic)
+  fab!(:post) { Fabricate(:post, topic:) }
+  let(:signature_image_url) { "https://example.com/signature.png" }
+
+  context "when signatures plugin is enabled" do
+    before do
+      enable_current_plugin
+      SiteSetting.signatures_enabled = true
+      SiteSetting.signatures_advanced_mode = false
+    end
+
+    context "when signatures are visible by default" do
+      before { SiteSetting.signatures_visible_by_default = true }
+
+      it "allows user to set an image signature and displays it below posts" do
+        sign_in(user)
+
+        visit "/my/preferences/profile"
+
+        expect(page).to have_content(I18n.t("js.signatures.enable_signatures"))
+        expect(page).to have_content(I18n.t("js.signatures.my_signature"))
+        expect(page).to have_field(placeholder: I18n.t("js.signatures.signature_placeholder"))
+
+        check I18n.t("js.signatures.show_signatures")
+        fill_in placeholder: I18n.t("js.signatures.signature_placeholder"), with: signature_image_url
+
+        click_button I18n.t("js.save")
+        expect(page).to have_content(I18n.t("js.saved"))
+
+        user.reload
+
+        post = Fabricate(:post, topic:, user:, raw: "This is a test post with signature")
+        
+        visit post.url
+
+        expect(page).to have_css("img.signature-img[src='#{signature_image_url}']")
+      end
+
+      it "does not show signatures when user has disabled them" do
+        sign_in(user)
+
+        user.custom_fields["signature_url"] = signature_image_url
+        user.custom_fields["see_signatures"] = false
+        user.save_custom_fields
+
+        post = Fabricate(:post, topic:, user:)
+
+        visit topic.url
+
+        expect(page).to have_no_css("img.signature-img")
+      end
+
+      it "shows signatures to other users when signatures_visible_by_default is true" do
+        user.custom_fields["signature_url"] = signature_image_url
+        user.save_custom_fields
+
+        post = Fabricate(:post, topic:, user:)
+
+        sign_in Fabricate(:user)
+
+        visit topic.url
+
+        expect(page).to have_css("img.signature-img[src='#{signature_image_url}']")
+      end
+    end
+
+    context "when signatures are not visible by default" do
+      before { SiteSetting.signatures_visible_by_default = false }
+
+      it "does not show signatures when user hasn't opted in" do
+        user.custom_fields["signature_url"] = signature_image_url
+        user.save_custom_fields
+
+        post = Fabricate(:post, topic:, user:)
+
+        sign_in Fabricate(:user)
+
+        visit topic.url
+
+        expect(page).to have_no_css("img.signature-img")
+      end
+
+      it "allows users to opt into seeing signatures" do
+        user.custom_fields["signature_url"] = signature_image_url
+        user.save_custom_fields
+
+        post = Fabricate(:post, topic:, user:)
+
+        sign_in Fabricate(:user)
+
+        visit "/my/preferences/profile"
+
+        check I18n.t("js.signatures.show_signatures")
+        click_button I18n.t("js.save")
+
+        visit topic.url
+
+        expect(page).to have_css("img.signature-img[src='#{signature_image_url}']")
+      end
+    end
+  end
+
+  context "when signatures plugin is disabled" do
+    before { SiteSetting.signatures_enabled = false }
+
+    it "does not show signatures or preferences" do
+      user.custom_fields["signature_url"] = signature_image_url
+      user.save_custom_fields
+
+      post = Fabricate(:post, topic:, user:)
+
+      sign_in(user)
+
+      visit topic.url
+
+      expect(page).to have_no_css("img.signature-img")
+
+      visit "/my/preferences/profile"
+
+      expect(page).to have_no_content(I18n.t("js.signatures.enable_signatures"))
+    end
+  end
+end