cljs.test file-and-line detection is not useful in browser testing

Question

cljs.test reports using do-report, which adds file and line information computed from javascript stack traces. In chrome at least, these stack traces are not useful:

`
"Error

at http://localhost:3449/js/cljs/test.js:261:69
at cljs$test$do_report (http://localhost:3449/js/cljs/test.js:268:3)
at http://localhost:3449/js/test/test_tests.js:491:21
at test.test_tests.test_has_fails.cljs$lang$test (http://localhost:3449/js/test/test_tests.js:502:4)
at http://localhost:3449/js/cljs/test.js:384:42
at http://localhost:3449/js/cljs/test.js:387:4
at cljs$test$run_block (http://localhost:3449/js/cljs/test.js:320:13)
..."

`

The file-and-line stack trace parser doesn't parse this correctly, resulting in a message like this:

FAIL in (test-function) (at http:384:42)

Note the lack of a useful file/namespace reference, and that the line number refers to the compiled javascript rather than the source clojurescript.

Answer 1

_Comment made by: sfnelson_

Prior to the release of cljs.test my company maintained an internal port of clojure.test that did better reporting than cljs.test's by adding source metadata from {{&form}} to the {{do-report}} calls generated by {{assert-expr}}. This approach was great for internal use but might not be suitable for cljs.test as it could reduce portability of {{assert-expr}} between clojure and clojurescript. Another approach could be dynamically bind source metadata in the body generated by {{try-expr}}. I'd be willing to implement and contribute code if you can provide some indication of your preferred approach.

Our version of {{assert-expr}} also injected a 'reporter function', {{(function(a,b,c){a.apply(b.c)})}}, which we would invoke from report, e.g. {{(reporter (.-debug js/console) js/console args)}}. This causes the clickable link on the right hand side of chrome's console output to link to the source map location of the test expression, rather than the report function.

Answer 2

Comment made by: dnolen

The correct thing to do here is to move the browser REPL stacktrace parsing into a shared library i.e. {{.cljc}} that can be loaded into either environment to handle browser difference.

Answer 3

Reference: https://clojure.atlassian.net/browse/CLJS-1255 (reported by alex+import)