tests: functional: Fix reloading error page during install/uninstall

- When an error page is shown during installation/uninstallation, no automatic
refresh of the page happens. Fix this by reloading the page when error is shown.

- When error page is shown, the document.readyState is "interactive" (meaning
that page load is completed but other resources such as images are being
loaded). So, checking for error page is never happening.

- Also when reloading an error page, WebDriverException may happen so use the
wait_for_page_update() utility to perform the page reloads.

Tests:

- Run functional tests for bepasty. When installing the app, stop apache web
server. Let an error page be shown. Then start the server again. Without the
patch, the error page is never reloaded. With the patch, the error page is
reloaded and tests succeed.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/tests/functional/__init__.py

@@ -208,6 +208,12 @@ def wait_for_page_update(browser, timeout=300, expected_url=None):
     WebDriverWait(browser, timeout).until(_PageLoaded(page_body, expected_url))
 
 
+def page_reload(browser):
+    """Reload the page."""
+    with wait_for_page_update(browser):
+        browser.visit(browser.url)
+
+
 def _get_site_url(site_name):
     if site_name.startswith('share'):
         site_name = site_name.replace('_', '/')
@@ -457,10 +463,10 @@ def install(browser, app_name):
         script = 'return (document.readyState == "complete") && ' \
             '(!Boolean(document.querySelector(".app-operation"))) &&' \
             '(!Boolean(document.querySelector(".app-just-installed")));'
-        if not browser.execute_script(script):
+        if browser.is_element_present_by_css('.neterror'):
+            page_reload(browser)
+        elif not browser.execute_script(script):
             time.sleep(0.1)
-        elif browser.is_element_present_by_css('.neterror'):
-            browser.visit(browser.url)
         elif browser.is_element_present_by_css('.alert-danger'):
             break
         elif (browser.is_element_present_by_css('.app-checking-availability')
@@ -500,10 +506,10 @@ def uninstall(browser, app_name):
     while True:
         script = 'return (document.readyState == "complete") && ' \
             '(!Boolean(document.querySelector(".app-operation")));'
-        if not browser.execute_script(script):
+        if browser.is_element_present_by_css('.neterror'):
+            page_reload(browser)
+        elif not browser.execute_script(script):
             time.sleep(0.1)
-        elif browser.is_element_present_by_css('.neterror'):
-            browser.visit(browser.url)
         elif browser.is_element_present_by_css('.alert-danger'):
             raise RuntimeError('Uninstall failed')
         else: