Support unit tests written in Clarity - #[test]

[lgalabru]

A non negligible amount of developers want to write their tests in clarity.
I wonder if this is something we could support "simply" by introducing a #[test] command processor.
It could look like:

(define-public (increment-counter (step uint))
    (+ step (data-var-get counter)))

;; #[test]
(define-public (test-increment)
    (asserts! (is-eq u1 (increment-counter u1)) (err u1001)))

I think we would still be using js/ts for coordinating / structuring the test execution, but at least the logic would be written in clarity - developers would be calling something like:

describe("Counter contract tests", () => {
  it("ensures counter is counting", () => {
    const { result, events } = simnet.assertPublicFn(
      "counter",
      "test-increment",
      [Cl.uint(1)],
      deployer,
    );
  });
});

So when deploying such contracts, I think the #[test] directive would exclude the subsequent clarity statement from the contract?

[hugocaillard]

@lgalabru What do you think about the clarunit approach? https://www.npmjs.com/package/@stacks/clarunit
(Similar ideas)

[lgalabru]

Oh nice, that probably works. I guess with this present proposal, clarity testing clarity would become a first class citizen.
We can keep this issue open for a few week and passively collect feedbacks / demands?