cljs.test / clojure.test: known gaps in squint's implementation

This list captures behavior the squint (and cherry) cljs.test built-ins don't yet match against the canonical clojure.test / cljs.test. The ordering is rough priority — high-impact correctness gaps first, then extensibility gaps, then polish.

Correctness — likely to bite real users

1. Fixtures are global, not per-namespace ✅ DONE

~~set-each-fixtures! / set-once-fixtures! write into the single global env. Real clojure.test keys fixtures by namespace ((alter-meta! ns ...)). Today, two test namespaces each calling (use-fixtures :each ...) will clobber each other; whichever loaded last wins for every test.~~

Fixed: :each-fixtures and :once-fixtures are now {ns-str → vec} maps; core-deftest stashes :ns in the test fn's meta; test-var and run-tests look fixtures up by that ns. The 1-arg legacy setters target a nil-keyed bucket for back-compat. Regression tests in both the squint smoke suite and cherry's cross_platform_test.

2. run-tests doesn't reset counters per call ✅ DONE

~~(run-tests) auto-inits the env only when *current-env* is nil. A second (run-tests) in the same module reuses (and inflates) the existing counters. Tests that themselves invoke run-tests (squint and cherry's own runtime tests do this) emit summaries showing cumulative counts, not per-run counts.~~

Fixed: run-tests saves the caller's :report-counters, runs against fresh ones, restores on return. The returned summary map reflects only that run. Inner run-tests calls now show their own per-call summary instead of polluted cumulative totals. Regression tests in both repos.

3. Quoted-symbol emission breaks is reporting

The shared macro (:name '~name) would expand to cljs.core.symbol(...) under squint, which doesn't exist at runtime. We worked around it by storing :name as a string (and assert-expr uses (pr-str form)). Result: (:name (meta test-fn)) is a string, not a symbol — diverges from clojure.test's expectations and breaks code that calls namespace/name on it.

Fix sketch: fix squint's quote emission to route through squint_core.symbol (already a real fn) instead of the literal cljs.core.symbol. Then revert macros to symbol form for parity with cherry/cljs.test.

Extensibility — currently impossible to extend

4. assert-expr is hardcoded

Real clojure.test/assert-expr is a multimethod keyed on the head of the form inside (is ...). Users add new assertions by defmethod-ing it. Ours is a case over =, thrown?, thrown-with-msg?. No extension point.

Fix sketch: make assert-expr a multimethod (or a registry of {op-sym (fn [msg form] ...)}) that the macro consults. Squint can ship the existing four cases as default methods.

5. report is hardcoded too ✅ DONE

~~clojure.test/report is a multimethod keyed on :type; users add methods to extend reporting (e.g. cljs-test-display). Ours is a single case defn.~~

Fixed: report is now a defmulti dispatching on [*current-reporter* (:type m)], matching cljs.test. The built-in reporter lives under :cljs.test/default; unknown combinations fall through to a no-op :default method. test-var now also emits :begin-test-var / :end-test-var so reporters can bracket per-var output. Smoke test report-is-multimethod-test covers user-defined extensions.

6. test-var is a plain fn

clojure.test/test-var is a multimethod (:default impl is what everyone uses, but it's overridable). Same idea as report.

Coverage gaps — features that exist but are partial

7. :begin-test-ns / :end-test-ns are never emitted ✅ DONE

~~We support the report types in report's case, but run-tests never fires them. Real clojure.test brackets each ns it processes with these events; reporters use them to group output.~~

Fixed: run-vars-with-once-fixtures now brackets each ns's tests with :begin-test-ns / :end-test-ns reports, so (t/run-tests 'my.ns) prints Testing my.ns like cljs.test. Anonymous (nil-ns) groups are skipped. Smoke tests assert the lines appear.

8. No (t/async done body) form ✅ DONE

~~Real cljs.test async tests use (async done (do ... (done))). We use ^:async on the deftest plus a Promise-returning body. Functionally equivalent but different surface — code copied from a CLJS project won't run.~~

Added: core-async macro expands (async done body) to (js/Promise. (fn [done] body)). test-var already awaits any Promise-returning test fn, so no additional plumbing was needed — the ^:async form keeps working too. Regression tests in both repos.

9. Test discovery is registration-based, not metadata-based

clojure.test/run-tests walks ns-publics and filters by (:test (meta var)). We use a separate test-registry because squint has no var metadata at runtime. That works for tests defined via our deftest, but a user who manually attaches :test true to a defn won't be picked up.

Note: unclear this is fixable without a var registry — probably accept the divergence and document.

10. ~~successful? reads global counters~~ — non-issue

On re-read: successful? takes a counters map and reads :fail/:error from it. No global state involved. Removed.

Polish — cosmetic but worth fixing

11. Inner run-tests calls produce double summary output ✅ DONE

~~Two of cherry's cross_platform_test cases call run-tests inside test bodies (testing the runtime itself). Each emits its own :summary line, on top of the outer test run's summary.~~

Side-effect of #2: each inner run-tests now reports its own per-call summary with accurate counts (instead of cumulative pollution). Still multiple summary lines, but the lines are correct and informative — not noise. Closing.

12. :report-counters :summary increments needlessly

report calls (inc-report-counter! :type) unconditionally, including for :type :summary. Adds a meaningless counter to the env map.

13. No *test-out* redirection

Output goes hard-wired to js/console.log/js/console.error. Real cljs.test lets users rebind via *report-out* or per-method.

14. Cherry runtime and squint runtime drifted in subtle ways

Both implement the same surface but are separate .cljs files. Easy to fix one and forget the other. Could share via a .cljc if we factor out the few JS-vs-CLJS differences.