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CHAPTER 10
Input Validation and Test Organisation
Over the next few chapters we’ll talk about testing and implementing validation of user
inputs. We’ll also take the opportunity to do a little tidying up—both in our application
code, and also in our tests.
Validation FT: Preventing Blank Items
As our first few users start using the site, we’ve noticed they sometimes make mistakes
that mess up their lists, like accidentally submitting blank list items, or accidentally
inputting two identical items to a list. Computers aremeant to help stop us frommaking
silly mistakes, so let’s see if we can get our site to help.
Here’s the outline of an FT:
functional_tests/tests.py (ch10l001).
def
test_cannot_add_empty_list_items
(
self
):
# Edith goes to the home page and accidentally tries to submit
# an empty list item. She hits Enter on the empty input box
# The home page refreshes, and there is an error message saying
# that list items cannot be blank
# She tries again with some text for the item, which now works
# Perversely, she now decides to submit a second blank list item
# She receives a similar warning on the list page
# And she can correct it by filling some text in
self
.
fail
(
'write me!'
)
That’s all very well, but before we go any further—our functional tests file is beginning
to get a little crowded. Let’s split it out into several files, in which each has a single test
method.
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