Review and rework tests asserting is not True for exists(pattern)

[tracywalker]

I believe it isn't always the best practice to assert that a pattern or text does not exist. For example:

expected = exists('Mozilla', FirefoxSettings.FIREFOX_TIMEOUT)
assert expected is not True, 'Mozilla doesn't appear history.

What if 'Mozilla' exists elsewhere? Narrowing the search region is probably acceptable. Another way may be to create new pattern containing context of where 'Mozilla' exists. The assert true that that pattern exists.

Searching the code I also found at least one instance of a test that used assert is not True for exists(pattern)similar(.9) Increasing the similarity above default is certainly not good practice for asserting a pattern/text is not present as it possible to report falsely.

I'm filing this to issue to review all of the tests that are using this practice and implement a more true and reliable method. The solutions will be made on a case by case basis as I don't think this is a one-size-fits-all situation.