chore: Restore previous value if input value is auto-submitted

Author: gadenbuie

js/chat/chat.ts

@@ -239,15 +239,21 @@ class ChatInput extends LightElement {
     value: string,
     { submit = false, focus = false }: ChatInputSetInputOptions = {}
   ): void {
+    // Store previous value to restore post-submit (if submitting)
+    const oldValue = this.textarea.value;
+
     this.textarea.value = value;
 
     // Simulate an input event (to trigger the textarea autoresize)
     const inputEvent = new Event("input", { bubbles: true, cancelable: true });
     this.textarea.dispatchEvent(inputEvent);
 
     if (submit) {
-      this.#sendInput(focus);
-    } else if (focus) {
+      this.#sendInput(false);
+      if (oldValue) this.setInputValue(oldValue);
+    }
+
+    if (focus) {
       this.textarea.focus();
     }
   }

tests/playwright/shiny/components/chat/update_user_input/test_chat_update_user_input.py

@@ -31,11 +31,26 @@ def test_validate_chat_update_user_input(page: Page, local_app: ShinyAppProc) ->
 
     # Set the input and move focus ----
     set_and_focus.click()
-    chat.expect_user_input("Input was set and focused, but not submitted.")
+    set_msg = "Input was set and focused, but not submitted."
+    chat.expect_user_input(set_msg)
     expect(chat.loc_input_button).to_be_enabled()
     expect(chat.loc_input).to_be_focused()
 
     # Auto submit ----
+    submit.loc.focus()
+    submit.click()
+    chat.expect_user_input(set_msg) # User doesn't lose what they had written
+    chat.expect_latest_message("You said: This chat was sent on behalf of the user.")
+    expect(chat.loc_input_button).to_be_enabled()
+    expect(chat.loc_input).not_to_be_focused()
+
+    # Input remains cleared if previously clear (have to clear the input first)
+    chat.loc_input.focus()
+    while chat.loc_input.input_value():
+        chat.loc_input.press("Backspace")
+
+    chat.expect_user_input("")
+
     submit.loc.focus()
     submit.click()
     chat.expect_user_input("")