From 2cd87ccbcd1ef68c8d6c48ff418eb2291290282c Mon Sep 17 00:00:00 2001
From: philippe <t4rk@outlook.com>
Date: Tue, 9 Aug 2022 12:02:35 -0400
Subject: [PATCH 1/2] Improve error message when using fixtures but testing not
 installed.

---
 dash/testing/plugin.py | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/dash/testing/plugin.py b/dash/testing/plugin.py
index 4265589259..20eb26dffe 100644
--- a/dash/testing/plugin.py
+++ b/dash/testing/plugin.py
@@ -1,10 +1,17 @@
 # pylint: disable=missing-docstring,redefined-outer-name
-from typing import Any
-
 import pytest
 from .consts import SELENIUM_GRID_DEFAULT
 
 
+# pylint: disable=too-few-public-methods
+class MissingDashTesting:
+    def __init__(self, **kwargs):
+        raise Exception(
+            "dash[testing] was not installed. "
+            "Please install to use the dash testing fixtures."
+        )
+
+
 try:
     from dash.testing.application_runners import (
         ThreadedRunner,
@@ -16,14 +23,14 @@
     from dash.testing.composite import DashComposite, DashRComposite, DashJuliaComposite
 except ImportError:
     # Running pytest without dash[testing] installed.
-    ThreadedRunner = Any
-    ProcessRunner = Any
-    RRunner = Any
-    JuliaRunner = Any
-    Browser = Any
-    DashComposite = Any
-    DashRComposite = Any
-    DashJuliaComposite = Any
+    ThreadedRunner = MissingDashTesting
+    ProcessRunner = MissingDashTesting
+    RRunner = MissingDashTesting
+    JuliaRunner = MissingDashTesting
+    Browser = MissingDashTesting
+    DashComposite = MissingDashTesting
+    DashRComposite = MissingDashTesting
+    DashJuliaComposite = MissingDashTesting
 
 
 def pytest_addoption(parser):

From de5cd9d7d640c8a39c7df3d0705ca77127b726b1 Mon Sep 17 00:00:00 2001
From: philippe <t4rk@outlook.com>
Date: Fri, 12 Aug 2022 14:39:34 -0400
Subject: [PATCH 2/2] Update changelog.

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 41c01cd93a..54bb6d4df9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 ### Fixed
 
 - [#2152](https://github.com/plotly/dash/pull/2152) Fix bug [#2128](https://github.com/plotly/dash/issues/2128) preventing rendering of multiple components inside a dictionary.
+- [#2187](https://github.com/plotly/dash/pull/2187) Fix confusing error message when trying to use pytest fixtures but `dash[testing]` is not installed.
 
 ## [2.6.1] - 2022-08-01