Add support for #[test_case] crate

[NicolasWent]

Hello,

When I use test_case crate with insta, I get wrong test name results and the tests are not passing when I don't modify the code and re-run them

Minimal reproducing example:

Cargo.toml:

[package]
name = "insta-suggestion"
version = "0.1.0"
edition = "2021"

[dependencies]
test-case = "3.3"
insta = { version = "1.41", features = ["yaml"] }

lib.rs:

use insta::assert_yaml_snapshot;
use test_case::test_case;

pub fn to_upper_case(text: &str) -> String {
    text.to_uppercase()
}

#[test_case("Hello World" ; "test_hello_world")]
#[test_case("Insta is fun" ; "test_insta_is_fun")]
fn test_function(text: &str) {
    let res = to_upper_case(text);
    assert_yaml_snapshot!(res);
}

What happens

Running cargo test will create two files: insta_suggestion__function-2.snap.new and insta_suggestion__function.snap.new

If I re-run cargo test, it will fail everytime

Expected output

The two files created should have the right name with "test_hello_world" and "test_insta_is_fun" instead of "test_function"

Aditionaly, if we re-run cargo test without changing anything, the tests shouldn't fail

Why this would be a good features

Pros

insta seems to be a crate designed to write tests faster, test_case also. It would be amazing to combine both and be able to write lots of tests very fast

Cons

Some features, specially with the @"" keyword or the vscode extension will be hard to work with

[CommanderStorm]

cannot reproduce using the example above. Did you review/accept the snapshots?

[CommanderStorm]

from insta's POV, the naming of the testcase correct. The functionon gets expanded to this, with test_case specific logic in a different scope. The function here is called multiple times => this is why you are seeing function-N as the snapshot name.

[CommanderStorm]

Discussions about interop between the crates is here:

• https://github.com/frondeus/test-case/issues/37#issuecomment-1518404846

=> using insta::with_settings seems like the best way that the community has come up with to tag this if using the function-N naming for testcases does not work for you.

[NicolasWent]

Thanks a lot

Yes I forgot to do cargo insta review sorry I am new to insta :'(

It works after cargo insta review :)

Could you show me an example of using it to rename my tests correctly?

[NicolasWent]

After using test case and insta in a bigger project I am getting the issue that the tests are getting "shuffled" like running multiple times cargo test ask me to review snapshots that were already reviewed

[CommanderStorm]

Could you show me an example of using it to rename my tests correctly

An example how suffixes can be set can be found here:

• https://github.com/frondeus/test-case/issues/37#issuecomment-1546910157

The same way also holds for the other settings.

[CommanderStorm]

tests are getting "shuffled" like running multiple times cargo test ask me to review snapshots that were already reviewed

What commands are you running and how are your test-cases structured? If for example the call-order is non-deterministic, using call numbers as a suffix won't work reliably.