Merge pull request #894 from plotly/remote-grid

Remote grid

dash/CHANGELOG.md

@@ -1,3 +1,9 @@
+## Unreleased
+
+### Fixed
+
+- [#829](https://github.com/plotly/dash/issues/829) Fixes the `--remote` pytest argument which was not effective in the code, adding a new argument `--remote-url` to support the selenium grid usage in the cloud.
+
 ## [1.2.0] - 2019-08-27
 ### Added
 - [#860](https://github.com/plotly/dash/pull/860) Adds a new arg `dev_tools_prune_errors` to `app.run_server` and `app.enable_dev_tools`. Default `True`, tracebacks only include user code and below. Set it to `False` for the previous behavior showing all the Dash and Flask parts of the stack.

dash/testing/browser.py

@@ -23,6 +23,7 @@
 )
 from dash.testing.dash_page import DashPageMixin
 from dash.testing.errors import DashAppLoadingError, BrowserError
+from dash.testing.consts import SELENIUM_GRID_DEFAULT
 
 
 logger = logging.getLogger(__name__)
@@ -32,21 +33,28 @@ class Browser(DashPageMixin):
     def __init__(
         self,
         browser,
+        remote=False,
+        remote_url=None,
         headless=False,
         options=None,
-        remote=None,
         download_path=None,
         percy_finalize=True,
         wait_timeout=10,
     ):
         self._browser = browser.lower()
+        self._remote_url = remote_url
+        self._remote = (
+            True
+            if remote_url and remote_url != SELENIUM_GRID_DEFAULT
+            else remote
+        )
         self._headless = headless
         self._options = options
         self._download_path = download_path
         self._wait_timeout = wait_timeout
         self._percy_finalize = percy_finalize
 
-        self._driver = until(lambda: self.get_webdriver(remote), timeout=1)
+        self._driver = until(self.get_webdriver, timeout=1)
         self._driver.implicitly_wait(2)
 
         self._wd_wait = WebDriverWait(self.driver, wait_timeout)
@@ -285,21 +293,11 @@ def open_new_tab(self, url=None):
             )
         )
 
-    def get_webdriver(self, remote):
+    def get_webdriver(self):
         try:
-            return (
-                getattr(self, "_get_{}".format(self._browser))()
-                if remote is None
-                else webdriver.Remote(
-                    command_executor=remote,
-                    desired_capabilities=getattr(
-                        DesiredCapabilities, self._browser.upper()
-                    ),
-                )
-            )
+            return getattr(self, "_get_{}".format(self._browser))()
         except WebDriverException:
             logger.exception("<<<Webdriver not initialized correctly>>>")
-            return None
 
     def _get_wd_options(self):
         options = (
@@ -333,8 +331,16 @@ def _get_chrome(self):
             },
         )
 
-        chrome = webdriver.Chrome(
-            options=options, desired_capabilities=capabilities
+        chrome = (
+            webdriver.Remote(
+                command_executor=self._remote_url,
+                options=options,
+                desired_capabilities=capabilities,
+            )
+            if self._remote
+            else webdriver.Chrome(
+                options=options, desired_capabilities=capabilities
+            )
         )
 
         # https://bugs.chromium.org/p/chromium/issues/detail?id=696481
@@ -372,8 +378,16 @@ def _get_firefox(self):
             "browser.helperApps.neverAsk.saveToDisk",
             "application/octet-stream",  # this MIME is generic for binary
         )
-        return webdriver.Firefox(
-            firefox_profile=fp, options=options, capabilities=capabilities
+        return (
+            webdriver.Remote(
+                command_executor=self._remote_url,
+                options=options,
+                desired_capabilities=capabilities,
+            )
+            if self._remote
+            else webdriver.Firefox(
+                firefox_profile=fp, options=options, capabilities=capabilities
+            )
         )
 
     @staticmethod

dash/testing/consts.py

@@ -0,0 +1 @@
+SELENIUM_GRID_DEFAULT = "http://localhost:4444/wd/hub"

dash/testing/plugin.py

@@ -1,5 +1,7 @@
 # pylint: disable=missing-docstring,redefined-outer-name
 import warnings
+from .consts import SELENIUM_GRID_DEFAULT
+
 
 try:
     import pytest
@@ -14,12 +16,10 @@
 except ImportError:
     warnings.warn("run `pip install dash[testing]` if you need dash.testing")
 
-WEBDRIVERS = {"Chrome", "Firefox", "Remote"}
+WEBDRIVERS = {"Chrome", "Firefox"}
 
 
 def pytest_addoption(parser):
-    # Add options to the pytest parser, either on the commandline or ini
-    # TODO add more options for the selenium driver.
     dash = parser.getgroup("Dash", "Dash Integration Tests")
 
     dash.addoption(
@@ -29,6 +29,19 @@ def pytest_addoption(parser):
         help="Name of the selenium driver to use",
     )
 
+    dash.addoption(
+        "--remote",
+        action="store_true",
+        help="instruct pytest to use selenium grid",
+    )
+
+    dash.addoption(
+        "--remote-url",
+        action="store",
+        default=SELENIUM_GRID_DEFAULT,
+        help="set a different selenium grid remote url if other than default",
+    )
+
     dash.addoption(
         "--headless",
         action="store_true",
@@ -99,6 +112,8 @@ def dashr_server():
 def dash_br(request, tmpdir):
     with Browser(
         browser=request.config.getoption("webdriver"),
+        remote=request.config.getoption("remote"),
+        remote_url=request.config.getoption("remote_url"),
         headless=request.config.getoption("headless"),
         options=request.config.hook.pytest_setup_options(),
         download_path=tmpdir.mkdir("download").strpath,
@@ -112,6 +127,8 @@ def dash_duo(request, dash_thread_server, tmpdir):
     with DashComposite(
         dash_thread_server,
         browser=request.config.getoption("webdriver"),
+        remote=request.config.getoption("remote"),
+        remote_url=request.config.getoption("remote_url"),
         headless=request.config.getoption("headless"),
         options=request.config.hook.pytest_setup_options(),
         download_path=tmpdir.mkdir("download").strpath,
@@ -125,6 +142,8 @@ def dashr(request, dashr_server, tmpdir):
     with DashRComposite(
         dashr_server,
         browser=request.config.getoption("webdriver"),
+        remote=request.config.getoption("remote"),
+        remote_url=request.config.getoption("remote_url"),
         headless=request.config.getoption("headless"),
         options=request.config.hook.pytest_setup_options(),
         download_path=tmpdir.mkdir("download").strpath,

tests/unit/test_browser.py

@@ -0,0 +1,44 @@
+import pytest
+from dash.testing.browser import Browser
+from dash.testing.consts import SELENIUM_GRID_DEFAULT
+
+
+@pytest.mark.parametrize("browser_type", ("Chrome", "Firefox"))
+def test_browser_smoke(browser_type, tmpdir):
+
+    browser = Browser(
+        browser=browser_type,
+        remote=False,
+        remote_url=SELENIUM_GRID_DEFAULT,
+        headless=True,
+        options=None,
+        download_path=tmpdir.mkdir("download").strpath,
+        percy_finalize=True,
+    )
+    assert browser.driver.name == browser_type.lower()
+
+
+def test_browser_use_remote_webdriver(tmpdir):
+    # test creation with remote=True
+    with pytest.raises(Exception):
+        Browser(
+            browser="Chrome",
+            remote=True,
+            remote_url=SELENIUM_GRID_DEFAULT,
+            headless=True,
+            options=None,
+            download_path=tmpdir.mkdir("download").strpath,
+            percy_finalize=True,
+        )
+
+    # test creation with remote_url other than default
+    with pytest.raises(Exception):
+        Browser(
+            browser="Chrome",
+            remote=False,
+            remote_url="http://token@any.selenium.grid:3333",
+            headless=True,
+            options=None,
+            download_path=tmpdir.mkdir("download").strpath,
+            percy_finalize=True,
+        )