boolean OR?

[jyn514]

I want to say something like this:

        let assert = Command::new("cargo").args(&["clean", "-p", "simple_project"])
            .current_dir("./tests/simple_project")
            .assert()
            .success()
            .or().stdout("package ID specification `simple_project` matched no packages");

But I don't see an or() function, or any function taking an arbitrary Predicate instead of a built-in assertion. In the meantime I can use https://doc.rust-lang.org/std/process/struct.Command.html#method.output, but it would be nice to have something built-in.

[epage]

As of right now, we can only handle predicates on one field at a time. I'm doubtful we'll be enabling ore complex ones.

In considering more complex expressions, one of the problems is the termination case, what causes us to evaluate all of it.

assert_cmd (at that time assert_cli) supported building expressions (before the execution happened). We simplified to being a thinner wrapping around Command but without us carrying any data because of that, we had to move the assertions to happen after the command runs. The problem we ran into was evaluating the expression. Its very easy to forget (though maybe we could play with must_use).

Then next problem is naming.

After that is how do we enable these arbitrary declarative-like logical conditions. Do we explicitly not support nested expressions? If we support them, what would the API look like?

With all of this, what is the ergonomics of the API compared to writing a more imperative logic.