Feat: UI testing automation with playwright (#12749)

### What problem does this PR solve?

This PR helps automate the testing of the ui interface using pytest
Playwright

### Type of change

- [x] New Feature (non-breaking change which adds functionality)
- [x] Other (please describe): test automation infrastructure

---------

Co-authored-by: Liu An <asiro@qq.com>

test/playwright/e2e/test_next_apps_chat.py

@@ -0,0 +1,126 @@
+import pytest
+from playwright.sync_api import expect
+
+from test.playwright.helpers.flow_context import FlowContext
+from test.playwright.helpers._auth_helpers import ensure_authed
+from test.playwright.helpers.flow_steps import flow_params, require
+from test.playwright.helpers._next_apps_helpers import (
+    RESULT_TIMEOUT_MS,
+    _fill_and_save_create_modal,
+    _goto_home,
+    _nav_click,
+    _open_create_from_list,
+    _select_first_dataset_and_save,
+    _send_chat_and_wait_done,
+    _unique_name,
+    _wait_for_url_or_testid,
+)
+
+
+def step_01_ensure_authed(ctx: FlowContext, step, snap):
+    with step("ensure logged in"):
+        ensure_authed(
+            ctx.page,
+            ctx.login_url,
+            ctx.active_auth_context,
+            ctx.auth_click,
+            seeded_user_credentials=ctx.seeded_user_credentials,
+        )
+    ctx.state["logged_in"] = True
+    snap("authed")
+
+
+def step_02_open_chat_list(ctx: FlowContext, step, snap):
+    require(ctx.state, "logged_in")
+    page = ctx.page
+    with step("open chat list"):
+        _goto_home(page, ctx.base_url)
+        _nav_click(page, "nav-chat")
+        expect(page.locator("[data-testid='chats-list']")).to_be_visible(
+            timeout=RESULT_TIMEOUT_MS
+        )
+    snap("chat_list_open")
+
+
+def step_03_open_create_modal(ctx: FlowContext, step, snap):
+    require(ctx.state, "logged_in")
+    page = ctx.page
+    with step("open create chat modal"):
+        _open_create_from_list(page, "chats-empty-create", "create-chat")
+    ctx.state["chat_modal_open"] = True
+    snap("chat_create_modal")
+
+
+def step_04_create_chat(ctx: FlowContext, step, snap):
+    require(ctx.state, "chat_modal_open")
+    page = ctx.page
+    chat_name = _unique_name("qa-chat")
+    ctx.state["chat_name"] = chat_name
+    with step("create chat app"):
+        _fill_and_save_create_modal(page, chat_name)
+        chat_detail = page.locator("[data-testid='chat-detail']")
+        try:
+            _wait_for_url_or_testid(page, r"/next-chat/", "chat-detail", timeout_ms=5000)
+        except AssertionError:
+            list_root = page.locator("[data-testid='chats-list']")
+            expect(list_root).to_be_visible(timeout=RESULT_TIMEOUT_MS)
+            card = list_root.locator(f"text={chat_name}").first
+            expect(card).to_be_visible(timeout=RESULT_TIMEOUT_MS)
+            card.click()
+        expect(chat_detail).to_be_visible(timeout=RESULT_TIMEOUT_MS)
+    ctx.state["chat_created"] = True
+    snap("chat_created")
+
+
+def step_05_select_dataset(ctx: FlowContext, step, snap):
+    require(ctx.state, "chat_created")
+    page = ctx.page
+    with step("select dataset"):
+        _select_first_dataset_and_save(page, timeout_ms=RESULT_TIMEOUT_MS)
+    ctx.state["chat_dataset_selected"] = True
+    snap("chat_dataset_saved")
+
+
+def step_06_ask_question(ctx: FlowContext, step, snap):
+    require(ctx.state, "chat_dataset_selected")
+    page = ctx.page
+    with step("ask question"):
+        _send_chat_and_wait_done(page, "what is ragflow", timeout_ms=60000)
+    snap("chat_stream_done")
+
+
+STEPS = [
+    ("01_ensure_authed", step_01_ensure_authed),
+    ("02_open_chat_list", step_02_open_chat_list),
+    ("03_open_create_modal", step_03_open_create_modal),
+    ("04_create_chat", step_04_create_chat),
+    ("05_select_dataset", step_05_select_dataset),
+    ("06_ask_question", step_06_ask_question),
+]
+
+
+@pytest.mark.p1
+@pytest.mark.auth
+@pytest.mark.parametrize("step_fn", flow_params(STEPS))
+def test_chat_create_select_dataset_and_receive_answer_flow(
+    step_fn,
+    flow_page,
+    flow_state,
+    base_url,
+    login_url,
+    active_auth_context,
+    step,
+    snap,
+    auth_click,
+    seeded_user_credentials,
+):
+    ctx = FlowContext(
+        page=flow_page,
+        state=flow_state,
+        base_url=base_url,
+        login_url=login_url,
+        active_auth_context=active_auth_context,
+        auth_click=auth_click,
+        seeded_user_credentials=seeded_user_credentials,
+    )
+    step_fn(ctx, step, snap)