test-suite semantics change makes my code infinite loop

[pnkfelix@…]

I was driving myself crazy trying to figure out why my Intel laptop was running my tests while my old Power Mac was taking forever to run them.

Eventually I realized it was because my Power Mac had downloaded a more recent version of Scheme Unit.

Consider the following:

#lang scheme

#;
(require (planet schematics/schemeunit:3) 
         (planet schematics/schemeunit:3/text-ui))
(require (planet "main.ss" ("schematics" "schemeunit.plt" 3 (= 3)))
         (planet "text-ui.ss" ("schematics" "schemeunit.plt" 3 (= 3))))

(define felixs-suite (test-suite ""))

(set! felixs-suite 
      (test-suite "snoc" 
                  felixs-suite
                  (test-case "test" (check-equal? 1 1))))

(run-tests felixs-suite)

I use the pattern above (in a more complicated manner but abstracted under a macro) to incrementally construct a set of test cases whose evaluation will be delayed until I invoke run-tests.

I can see in the Release Notes for version 3.4 that you say that you have changed things to allow "arbitrary expressions" in test suites. But I would claim that you have merely changed the set of allowable expressions, since my example worked better under the old semantics. The documentation should be improved to make this clearer.

---

In the meantime, can you tell me how you would achieve the effect I desire? (One way to think of the desired effect is like the Student Language's check-expect form, which delays invocation of the tests until the entire module body has been evaluated.)

[pnkfelix]

Just in case its not clear, there are actually two criteria that the above hack was trying to satisfy:

1. Adding test cases incrementally
2. All added tests are accumulated in a single test suite, where the one invocation of run-tests summarizes the results for all additions.

That second criteria is why the alternative design of building up a list of test suites and then doing (for-each run-tests suite-list would not suffice. If there were a procedure for turning a list of test suites into one single test suite, then the latter approach could be made to work, but I was not able to find such a procedure in the documentation.

[pnkfelix]

Ah. I figured out another work-around: force felixs-suite to be evaluated outside of the test-suite form.

#lang scheme
(require (planet schematics/schemeunit:3) 
         (planet schematics/schemeunit:3/text-ui))

(define felixs-suite (test-suite ""))

(set! felixs-suite 
      (let ((last-suite felixs-suite))
        (test-suite "snoc" 
                    last-suite
                    (test-case "test" (check-equal? 1 1)))))

(run-tests felixs-suite)

---

I still would like to know how you Scheme Unit experts would accomplish this effect, since I do not think my approach is particularly elegant. But now that my problem is solved, I regard this ticket as a documentation issue rather than one of functionality.

[schematics]

Thanks for reporting this. It's only by people telling me how they use SchemeUnit? that I can make it better. I'll add a programmatic API to construct test suites and test cases (i.e. make-test-suite, make-test-case etc.)

[schematics]

In the SchemeUnit? collection in the PLT trunk there are now make-test-case and make-test-suite functions. These will arrive in the Planet release as I get time to document and merge the changes across.