Useful new lint ideas

[wmanley]

Some ideas for lints inspired by code seen in the wild:

assert-true-has-no-effect

assert True

assert True statement has no effect. Remove this line or replace it with pass

assert True, "Things are fine"

assert True statement has no effect. Perhaps you meant logging.info("Things are fine")

assert-unnecessary-if

if stbt.match('abcd.png'):
    ...
else:
    assert False, "Didn't find abcd menu"

Unnecessary if statement. Consider rewriting with assert: assert stbt.match('abcd.png'), "Didn't find abcd menu"

But this code is fine:

if stbt.match('abcd.png'):
    ...
elif stbt.match('efgh.png'):
    ...
else:
    assert False, "Couldn't find menu"

return-unnecessary-if

This one is possibly more contentious:

if stbt.match('abcd.png'):
    return True
else:
    return False

This is preferred:

return bool(stbt.match('abcd.png'))

[drothlis]

slow-is-visible

Does is_visible use stbt.match_text or stbt.ocr as its first operation? You can often discard 90% of false-positives by doing a fast match operation first, for example:

return (stbt.match("image-that-is-present-in-this-and-some-other-screens.png") and 
        stbt.match_text("text that is only present in this screen"))

[wmanley]

Public FrameObject property returns MatchResult object

...or possibly another object that has a .frame member?

class Example(stbt.FrameObject):
    @property
    def is_good(self):
        return stbt.match("good.png")

Either explicitly make it a bool()

class Example(stbt.FrameObject):
    @property
    def is_good(self):
        return bool(stbt.match("good.png"))

or make the property private:

class Example(stbt.FrameObject):
    @property
    def _is_good(self):
        return stbt.match("good.png")