Fixed flakey check box by making a css_check function that behaves like css_click

As a result, changed inputfield to return the css, and all of the element.fill() to css_fill

common/djangoapps/terrain/ui_helpers.py

@@ -90,6 +90,38 @@ def css_click(css_selector, index=0, attempts=5, success_condition=lambda:True):
 
 
 @world.absorb
+def css_check(css_selector, index=0, attempts=5, success_condition=lambda: True):
+    """
+    Checks a check box based on a CSS selector, retrying if it initially fails.
+
+    This function handles errors that may be thrown if the component cannot be clicked on.
+    However, there are cases where an error may not be thrown, and yet the operation did not
+    actually succeed. For those cases, a success_condition lambda can be supplied to verify that the check worked.
+
+    This function will return True if the check worked (taking into account both errors and the optional
+    success_condition).
+    """
+    assert is_css_present(css_selector)
+    attempt = 0
+    result = False
+    while attempt < attempts:
+        try:
+            world.css_find(css_selector)[index].check()
+            if success_condition():
+                result = True
+                break
+        except WebDriverException:
+            # Occasionally, MathJax or other JavaScript can cover up
+            # an element temporarily.
+            # If this happens, wait a second, then try again
+            world.wait(1)
+            attempt += 1
+        except:
+            attempt += 1
+    return result
+
+
+@world.absorb
 def css_click_at(css, x=10, y=10):
     '''
     A method to click at x,y coordinates of the element

lms/djangoapps/courseware/features/problems_setup.py

@@ -142,34 +142,34 @@ def answer_problem(problem_type, correctness):
 
     elif problem_type == "multiple choice":
         if correctness == 'correct':
-            inputfield('multiple choice', choice='choice_2').check()
+            world.css_check(inputfield('multiple choice', choice='choice_2'))
         else:
-            inputfield('multiple choice', choice='choice_1').check()
+            world.css_check(inputfield('multiple choice', choice='choice_1'))
 
     elif problem_type == "checkbox":
         if correctness == 'correct':
-            inputfield('checkbox', choice='choice_0').check()
-            inputfield('checkbox', choice='choice_2').check()
+            world.css_check(inputfield('checkbox', choice='choice_0'))
+            world.css_check(inputfield('checkbox', choice='choice_2'))
         else:
-            inputfield('checkbox', choice='choice_3').check()
+            world.css_check(inputfield('checkbox', choice='choice_3'))
 
     elif problem_type == 'radio':
         if correctness == 'correct':
-            inputfield('radio', choice='choice_2').check()
+            world.css_check(inputfield('radio', choice='choice_2'))
         else:
-            inputfield('radio', choice='choice_1').check()
+            world.css_check(inputfield('radio', choice='choice_1'))
 
     elif problem_type == 'string':
         textvalue = 'correct string' if correctness == 'correct' else 'incorrect'
-        inputfield('string').fill(textvalue)
+        world.css_fill(inputfield('string'), textvalue)
 
     elif problem_type == 'numerical':
         textvalue = "pi + 1" if correctness == 'correct' else str(random.randint(-2, 2))
-        inputfield('numerical').fill(textvalue)
+        world.css_fill(inputfield('numerical'), textvalue)
 
     elif problem_type == 'formula':
         textvalue = "x^2+2*x+y" if correctness == 'correct' else 'x^2'
-        inputfield('formula').fill(textvalue)
+        world.css_fill(inputfield('formula'), textvalue)
 
     elif problem_type == 'script':
         # Correct answer is any two integers that sum to 10
@@ -181,8 +181,8 @@ def answer_problem(problem_type, correctness):
         if correctness == 'incorrect':
             second_addend += random.randint(1, 10)
 
-        inputfield('script', input_num=1).fill(str(first_addend))
-        inputfield('script', input_num=2).fill(str(second_addend))
+        world.css_fill(inputfield('script', input_num=1), str(first_addend))
+        world.css_fill(inputfield('script', input_num=2), str(second_addend))
 
     elif problem_type == 'code':
         # The fake xqueue server is configured to respond
@@ -281,7 +281,7 @@ def add_problem_to_course(course, problem_type, extraMeta=None):
 
 
 def inputfield(problem_type, choice=None, input_num=1):
-    """ Return the <input> element for *problem_type*.
+    """ Return the css element for *problem_type*.
     For example, if problem_type is 'string', return
     the text field for the string problem in the test course.
 
@@ -299,7 +299,7 @@ def inputfield(problem_type, choice=None, input_num=1):
     assert world.is_css_present(sel)
 
     # Retrieve the input element
-    return world.browser.find_by_css(sel)
+    return sel
 
 
 def assert_checked(problem_type, choices):
@@ -312,7 +312,7 @@ def assert_checked(problem_type, choices):
 
     all_choices = ['choice_0', 'choice_1', 'choice_2', 'choice_3']
     for this_choice in all_choices:
-        element = inputfield(problem_type, choice=this_choice)
+        element = world.css_find(inputfield(problem_type, choice=this_choice))
 
         if this_choice in choices:
             assert element.checked
@@ -321,5 +321,5 @@ def assert_checked(problem_type, choices):
 
 
 def assert_textfield(problem_type, expected_text, input_num=1):
-    element = inputfield(problem_type, input_num=input_num)
+    element = world.css_find(inputfield(problem_type, input_num=input_num))
     assert element.value == expected_text