FIX: Prevent proofreading when there is no content (#779)

assets/javascripts/initializers/ai-helper.js

@@ -1,10 +1,23 @@
 import { withPluginApi } from "discourse/lib/plugin-api";
+import i18n from "discourse-common/helpers/i18n";
 import ModalDiffModal from "../discourse/components/modal/diff-modal";
 
 function initializeProofread(api) {
   api.addComposerToolbarPopupMenuOption({
     action: (toolbarEvent) => {
       const modal = api.container.lookup("service:modal");
+      const composer = api.container.lookup("service:composer");
+      const toasts = api.container.lookup("service:toasts");
+
+      if (composer.model.reply?.length === 0) {
+        toasts.error({
+          duration: 3000,
+          data: {
+            message: i18n("discourse_ai.ai_helper.proofread.no_content_error"),
+          },
+        });
+        return;
+      }
 
       modal.show(ModalDiffModal, {
         model: {

config/locales/client.en.yml

@@ -241,7 +241,6 @@ en:
           one: "This model is currently used by the %{settings} setting. If misconfigured, the feature won't work as expected."
           other: "This model is currently used by the following settings: %{settings}. If misconfigured, features won't work as expected. "
 
-
         preconfigured_llms: "Select your LLM"
         preconfigured:
           none: "Configure manually..."
@@ -331,6 +330,8 @@ en:
             prompt: "This post contains non-captioned images. Would you like to enable automatic AI captions on image uploads? (This can be changed in your preferences later)"
             confirm: "Enable"
             cancel: "Don't ask again"
+        proofread:
+          no_content_error: "Unable to proofread text, please add some content to proofread."
 
       reviewables:
         model_used: "Model used:"

spec/system/ai_helper/ai_proofreading_spec.rb

@@ -10,6 +10,7 @@ RSpec.describe "AI Composer Proofreading Features", type: :system, js: true do
   end
 
   let(:composer) { PageObjects::Components::Composer.new }
+  let(:toasts) { PageObjects::Components::Toasts.new }
 
   it "proofreads selected text using the composer toolbar" do
     visit "/new-topic"
@@ -41,4 +42,16 @@ RSpec.describe "AI Composer Proofreading Features", type: :system, js: true do
       expect(composer.composer_input.value).to eq("hello world")
     end
   end
+
+  it "does not trigger proofread modal if composer is empty" do
+    visit "/new-topic"
+
+    # Simulate AI response
+    DiscourseAi::Completions::Llm.with_prepared_responses(["hello world"]) do
+      ai_toolbar = PageObjects::Components::SelectKit.new(".toolbar-popup-menu-options")
+      ai_toolbar.expand
+      ai_toolbar.select_row_by_name("Proofread Text")
+      expect(toasts).to have_error(I18n.t("js.discourse_ai.ai_helper.proofread.no_content_error"))
+    end
+  end
 end