Hello Peter,
I've always felt the current behaviour of assertQuerysetEqual was weird and
always wondered why it was not implement the way you suggest.
I think you're approach is clever and I can't think of a way it would break
backward compatibility except if .values_list('charfield', flat=True) is
used.
I'd suggest we go even further and raise a deprecation warning when falling
back to repr because of the first item is an instance of str so
we can eventually remove this weird behaviour entirely.
Cheers,
Simon
Le mardi 4 février 2020 11:35:16 UTC-5, Peter Inglesby a écrit :
>
> Hi folks,
>
> I always find the behaviour of assertQuerysetEqual surprising,
> particularly when I pass it two querysets that I expect to be the same, or
> when the second argument is a list of model instances.
>
> Under the covers, assertQuerysetEqual(xs, ys) is roughly equivalent to
> assert [repr(x) for x in xs] == ys, and an optional transform parameter can
> be passed in to be used instead of repr().
>
> So assertQuerysetEqual(qs1, qs2) is never going to do the right thing and
> there's always ten seconds of head scratching while I look at something
> like:
>
> AssertionError: Lists differ: ['<AMP: 10347111000001100>', '<AMP:
> 4814811000001108>'] != [<AMP: 10347111000001100>, <AMP: 4814811000001108>]
>
> I know that I can use assertCountEqual from the standard library, and I
> think at the very minimum this should be mentioned in the docs for
> assertQuerysetEqual.
>
> However, I'd like to go further and propose a change to
> assertQuerysetEqual so that if no transform argument is passed, and the
> second argument is not a list of strings, then transform is set to the
> identity function.
>
> As far as I can tell, this would not introduce a meaningful backwards
> incompatibility.
>
> I'm willing to do the work to add code and documentation etc.
>
> All the best,
>
> Peter.
>
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