Improve test_filter_jobs by skipping result sets without linux and windows platforms (#2832)

tests/jenkins/pages/treeherder.py

@@ -296,7 +296,7 @@ class TreeherderPage(Base):
 
         @property
         def builds(self):
-            return [self.Build(self.page, root=el) for el in self.find_elements(*self._platform_locator)]
+            return [self.Build(self.page, root=el) for el in self.find_elements(*self._platform_locator) if el.is_displayed()]
 
         @property
         def datestamp(self):

tests/jenkins/tests/test_filter_jobs.py

@@ -3,16 +3,24 @@ import pytest
 from pages.treeherder import TreeherderPage
 
 
+def platforms(result_set):
+    parts = []
+    for build in result_set.builds:
+        parts.extend(build.platform_name.lower().split())
+    return set(parts)
+
+
+def linux_and_windows(result_set):
+    return {'linux', 'windows'}.issubset(platforms(result_set))
+
+
 @pytest.mark.nondestructive
 def test_filter_jobs(base_url, selenium):
     """Open resultset page and filter for platform"""
     page = TreeherderPage(selenium, base_url).open()
-    platform = u'Linux'
-
-    page.filter_by(platform)
-    assert platform in page.result_sets[0].builds[0].platform_name
-
-    page.clear_filter()
-    platform2 = u'Windows'
-    page.filter_by(platform2)
-    assert platform not in page.result_sets[0].builds[0].platform_name
+    # select the first result set with linux and windows platforms
+    result_set = next(r for r in page.result_sets if linux_and_windows(r))
+    assert {'linux', 'windows'}.issubset(platforms(result_set))
+    page.filter_by('linux')
+    assert 'linux' in platforms(result_set)
+    assert 'windows' not in platforms(result_set)