adding __hash__ method to webelement so that one can put found elements in a python set for uniqueness

Fixes Issue #7011

Author: lukeis

py/selenium/webdriver/remote/webelement.py

@@ -14,6 +14,7 @@
 
 
 """WebElement implementation."""
+import hashlib
 import os
 import zipfile
 try:
@@ -382,6 +383,9 @@ def find_elements(self, by=By.ID, value=None):
         return self._execute(Command.FIND_CHILD_ELEMENTS,
                              {"using": by, "value": value})['value']
 
+    def __hash__(self):
+        return int(hashlib.md5(self._id.encode('utf-8')).hexdigest(), 16)
+
     def _upload(self, filename):
         fp = StringIO()
         zipped = zipfile.ZipFile(fp, 'w', zipfile.ZIP_DEFLATED)

py/test/selenium/webdriver/common/element_equality_tests.py

@@ -37,6 +37,13 @@ def testDifferentElementsAreNotEqual(self):
 
         self.assertNotEqual(body, div)
 
+    def testSameElementsFoundDifferentWaysShouldNotBeDuplicatedInASet(self):
+        self._loadSimplePage()
+        body = self.driver.find_element(By.TAG_NAME, "body")
+        xbody = self.driver.find_elements(By.XPATH, "//body")
+        s = set(xbody)
+        s.add(body)
+        self.assertEqual(1, len(s))
 
     def _pageURL(self, name):
         return "http://localhost:%d/%s.html" % (self.webserver.port, name)