Replace Trix with Lexxy

test/test_helpers/rich_text_editor_helper.rb

@@ -0,0 +1,56 @@
+# Drives the rich text editor in the composer. Encapsulates all editor-specific
+# selectors and interactions so tests describe behavior, not the editor's DOM.
+module RichTextEditorHelper
+  # Rails' built-in helper drives Trix; this drives Lexxy
+  def fill_in_rich_text_area(id, with:)
+    find("lexxy-editor##{id}").execute_script("this.value = arguments[0]", with)
+  end
+
+  def composer_editor
+    find("#composer lexxy-editor .lexxy-editor__content")
+  end
+
+  def type_in_composer(text)
+    composer_editor.click
+    composer_editor.send_keys(text)
+  end
+
+  def press_in_composer(*keys)
+    composer_editor.send_keys(*keys)
+  end
+
+  # The rich text button is only displayed for fine-pointer devices, a media
+  # query headless Chrome doesn't satisfy, so click it directly.
+  def toggle_rich_text_toolbar
+    page.execute_script("document.querySelector('#composer .composer__rich-text-btn').click()")
+  end
+
+  # Waits for the suggestion to appear, then commits the selected one with Tab.
+  def pick_mention(name)
+    assert_selector ".lexxy-prompt-menu__item", text: name
+    composer_editor.send_keys :tab
+  end
+
+  def paste_in_composer(text)
+    composer_editor.click
+
+    page.execute_script(<<~JS, text)
+      const content = document.querySelector("#composer lexxy-editor .lexxy-editor__content")
+      const event = new ClipboardEvent("paste", { bubbles: true, cancelable: true, clipboardData: new DataTransfer() })
+      event.clipboardData.setData("text/plain", arguments[0])
+      content.dispatchEvent(event)
+    JS
+  end
+
+  def assert_composer_text(text)
+    assert_selector "#composer lexxy-editor .lexxy-editor__content", text: text
+  end
+
+  def assert_composer_empty
+    assert_no_selector "#composer lexxy-editor .lexxy-editor__content", text: /./
+  end
+
+  def assert_edit_editor_text(text)
+    assert_selector ".message__body-content--editing lexxy-editor", text: text
+  end
+end