As Greg pointed out, HSpec does have an option to output just the failed tests. I looked at the example on the Chell project home page and converted the example tests into these hspec style specs:
import Test.Hspec (Specs, descriptions, describe, it) import Test.Hspec.Runner (hHspecWithFormat) import Test.Hspec.Formatters (failed_examples) import Test.Hspec.HUnit import Test.HUnit import System.IO (stdout)
-- some functions to test equal = (==) greater = (>) equalWithin = undefined equalLines = (==)
specs :: IO Specs specs = descriptions [ describe "number comparison module" [ it "can check for equality" (assertBool "1 should equal 1" $ equal 1 1), it "can compare order" (assertBool "2 should be greater than 1" $ greater 2 1), it "can compare eqauality with floating point numbers" (assertBool "1.0001 should be close enough to 1.0" $ equalWithin 1.0001 1.0 0.01) ], describe "text comparison module" [ it "can compare strings for equality" (let str1 = "foo\nbar\nbaz" :: String str2 = "foo\nbar\nqux" :: String in assertBool "foo\\nbar\\nbaz shouldn't equal foo\\nbar\\nqux" $ equalLines str1 str2) ]]
main = hHspecWithFormat (failed_examples True) stdout specs
And when run, got the following output in red text since it's only reporting failures: ] x can compare eqauality with floating point numbers FAILED [1] ] x can compare strings for equality FAILED [2] ] ] 1) number comparison module can compare eqauality with floating point numbers FAILED ] Prelude.undefined ] ] 2) text comparison module can compare strings for equality FAILED ] foo\nbar\nbaz shouldn't equal foo\nbar\nqux ] ] Finished in 0.0000 seconds ] ] 4 examples, 2 failures You can write provide your own formatter if that's not what you'd like to see. You also don't have to use the HUnit assertion text either; you could use the following function to make your specs even more like your Chell example, at the cost of losing the extra output description:
assert = assertBool ""
Hspec uses HUnit TestCases and assertions but also supports QuickCheck properties almost exactly the same way Chell does. The hspec project homepage (https://github.com/trystan/hspec) has more examples, including the specs for hspec itself.
Trystan Spangler
From: "John Millikin"
I am confused also, as to both what output you don't like that motivated chell and what exactly hspec silences :) Suffice to say I am able to get a small relevant error message on failure with hspec. I am adding the hspec maintainer to this e-mail- he can answer any of your questions.
The output I didn't like wasn't coming from HUnit, it was coming from the test aggregator I used (test-framework). It prints one line per test case run, whether it passed or failed. That means every time I ran my test suite, it would print *thousands* of lines to the terminal. Any failure immediately scrolled up and out of sight, so I'd have to either Ctrl-C and hunt it down, or wait for the final report when all the tests had finished running. Chell does the same thing as test-framework (aggregates tests into suites, runs them, reports results), but does so quietly. It only reports failed and aborted tests.