Added deletion tests

cms/djangoapps/contentstore/features/upload.feature

@@ -5,7 +5,7 @@ Feature: Upload Files
         Given I have opened a new course in Studio
         And I go to the files and uploads page
         When I upload the file "test"
-        Then I see the file "test" was uploaded
+        Then I should see the file "test" was uploaded
         And The url for the file "test" is valid
 
     Scenario: Users can update files
@@ -13,7 +13,14 @@ Feature: Upload Files
         And I go to the files and uploads page
         When I upload the file "test"
         And I upload the file "test"
-        Then I see only one "test"
+        Then I should see only one "test"
+
+    Scenario: Users can delete uploaded files
+        Given I have opened a new course in studio
+        And I go to the files and uploads page
+        When I upload the file "test"
+        And I delete the file "test"
+        Then I should not see the file "test" was uploaded
 
     Scenario: Users can download files
         Given I have opened a new course in studio

cms/djangoapps/contentstore/features/upload.py

@@ -35,10 +35,13 @@ def upload_file(step, file_name):
     world.css_find(close_css).click()
 
 
-@step(u'I see the file "([^"]*)" was uploaded$')
-def check_upload(step, file_name):
+@step(u'I should( not)? see the file "([^"]*)" was uploaded$')
+def check_upload(step, do_not_see_file, file_name):
     index = get_index(file_name)
-    assert index != -1
+    if do_not_see_file:
+        assert index == -1
+    else:
+        assert index != -1
 
 
 @step(u'The url for the file "([^"]*)" is valid$')
@@ -47,7 +50,18 @@ def check_url(step, file_name):
     assert r.status_code == 200
 
 
-@step(u'I see only one "([^"]*)"$')
+@step(u'I delete the file "([^"]*)"$')
+def delete_file(step, file_name):
+    index = get_index(file_name)
+    assert index != -1
+    delete_css = ".remove-asset-button"
+    world.css_click(delete_css, index=index)
+
+    prompt_confirm_css = 'li.nav-item > a.action-primary'
+    world.css_click(prompt_confirm_css)
+
+
+@step(u'I should see only one "([^"]*)"$')
 def no_duplicate(step, file_name):
     names_css = '.name-col > a.filename'
     all_names = world.css_find(names_css)