This naming was introduced in 2016 without explanation [1]. I find it
confusing because:
- It's reminiscent of "_app", which is a Python convention indicating
the variable is internal, so maybe avoid using it.
- It suggests there's some other "app" fixture I should be using (there
isn't, though).
The Python style guide describes using an underscore suffix to avoid
clashes with inbuilt names [1], which is sort of applicable if we need
to import the "app" module [2]. However, we can also avoid clashes by
choosing a different name, without the strange underscore.
[1]: 3b1d521c10
[2]: 78824f54fd/tests/app/main/views/test_forgot_password.py (L5)
We strip most whitespace as of:
https://github.com/alphagov/notifications-admin/pull/1701
However we are still getting some bad email addresses through, for
example one that had a leading zero-width space character. This means
that the user sees a validation error; really we should just deal with
the mess for them.
So this commit also includes characters without Unicode character
property "WSpace=Y" (which includes zero-width space) to those which are
stripped from form submissions.
List taken from here: https://en.wikipedia.org/wiki/Whitespace_character
See issue and discussion here: https://bugs.python.org/issue13391
