When we perform database queries in tests after the process running the
browser has started, we sometimes get failures in our test suite due to
both the tests and the browser accessing the database at the same time.
Furthermore, using `Poll.all` results in a database query, and doing so
after the process running the browser has started might result in
failures when running our test suite.
Links acting like buttons have a few disadvantages.
First, screen readers will announce them as "links". Screen reader users
usually associate links with "things that get you somewhere" and buttons
with "things that perform an action". So when something like "Delete,
link" is announced, they'll probably think this is a link which will
take them to another page where they can delete a record.
Furthermore, the URL of the link for the "destroy" action might be the
same as the URL for the "show" action (only one is accessed with a
DELETE request and the other one with a GET request). That means screen
readers could announce the link like "Delete, visited link", which is
very confusing.
They also won't work when opening links in a new tab, since opening
links in a new tab always results in a GET request to the URL the link
points to.
Finally, submit buttons work without JavaScript enabled, so they'll work
even if the JavaScript in the page hasn't loaded (for whatever reason).
For all these reasons (and probably many more), using a button to send
forms is IMHO superior to using links.
There's one disadvantage, though. Using `button_to` we create a <form>
tag, which means we'll generate invalid HTML if the table is inside
another form. If we run into this issue, we need to use `button_tag`
with a `form` attribute and then generate a form somewhere else inside
the HTML (with `content_for`).
Note we're using `button_to` with a block so it generates a <button>
tag. Using it in a different way the text would result in an <input />
tag, and input elements can't have pseudocontent added via CSS.
The following code could be a starting point to use the `button_tag`
with a `form` attribute. One advantage of this approach is screen
readers wouldn't announce "leaving form" while navigating through these
buttons. However, it doesn't work in Internet Explorer.
```
ERB:
<% content_for(:hidden_content, form_tag(path, form_options) {}) %>
<%= button_tag text, button_options %>
Ruby:
def form_id
path.gsub("/", "_")
end
def form_options
{ id: form_id, method: options[:method] }
end
def button_options
html_options.except(:method).merge(form: form_id)
end
Layout:
<%= content_for :hidden_content %> # Right before the `</body>`
```
System tests are about user experience, so instead of checking the slug
has been updated in the database, we check whether the page can be
accessed using the slug.
Note the budget group test is a bit different because the name of the
group isn't present in the budget group page.
JavaScript is used by about 98% of web users, so by testing without it
enabled, we're only testing that the application works for a very
reduced number of users.
We proceeded this way in the past because CONSUL started using Rails 4.2
and truncating the database between JavaScript tests with database
cleaner, which made these tests terribly slow.
When we upgraded to Rails 5.1 and introduced system tests, we started
using database transactions in JavaScript tests, making these tests much
faster. So now we can use JavaScript tests everywhere without critically
slowing down our test suite.
System tests are used to test the application from the user's point of
view. To test for specific exceptions, particularly regarding
authorization permissions, controller tests fit better.
Another option would be to test the page displayed shows a certain text,
like "Internal server error". I'm choosing controller tests because
they're faster and we're basically testing the same scenario many times
and we've already got a test checking what happens when users access a
page raising an exception.
Tests are easier to read now. Besides, since we changed the inputs in
the admin section so they don't use jQuery but an HTML date field,
formatting with %d/%m/%Y might not work depending on the browser's
locale.
We were repeating the same code over and over (with a few variants) to
setup tests which require an administrator. We can use a tag and
simplify the code.
There were places where we had two links pointing to the same place; one
link would be the name/title of a record, and one link would be under
the "actions" column.
This is confusing, since users would probably expect these links to
point to different places (which is what happens in other tables in the
admin section) and might try to click one of them and then the other
one and be surprised when they found out both of them go to the same
page.
