query_params option for assert_path/3 does not handle array values correctly

[idlehands]

When calling assert_path as like this on working code:

assert_path(~p"/my-path/", query_params: %{"my_key" => ["1", "2"]}

the assertion is erroring with the following error:

Expected query params to be "my_key=12" but got "my_key[]=1&my_key[]=2"

Looking further into it, it looks like PhoenixTest.Utils.stringify_keys_and_values/1 is the culprit.

I propose a fix where when the value of the query params is a list, it returns the params in the url array style.

After connecting with German over this, I plan to put in a PR to address this.

[idlehands]

Ha! I was being optimistic. While that Utils function is part of the problem, the assert_query_params/2 function in PhoenixTest.Assertions will need some work as well. It's leveraging URI, which does not handle query params arrays, at all, let alone how Phoenix creates them.

[germsvel]

Thanks @idlehands! Yes, I think both the stringify_keys_and_values/1 and the usage of URI in assert_query_params/2 will have issues with lists in queries. But I agree this is something we should fix (honestly surprised we didn't think of it the first time around).

Thanks for planning on opening a PR! Let me know if I can help with anything.