working on a fix for ticket #212

Stephen Blackheath [to cabal-devel] rubbernecking.trumpet.stephen at
Wed May 13 17:59:58 EDT 2009


I have done the same thing!  I posted a patch that includes a simple
test harness using the test-framework package, which allows QuickCheck
and HUnit tests to be mixed.  Would you consider using that instead,
because my tests are HUnit-based?

It is not integrated with 'cabal test', though.  Here's my patch:

Duncan Coutts is evaluating this patch for me at the moment.


Laszlo Nagy wrote:
> Hi All,
> Trying to create unit test suite.. work in progress. Comments are more
> than welcome!
> As an easy start, I wrote unit tests with QuickCheck on the following files:
>  Distribution/License.hs
>  Distribution/Package.hs
>  Distribution/Compiler.hs
>  Distribution/System.hs
>  Distribution/ModuleName.hs
>  Distribution/PackageDescription.hs
> I wrote simple properties like this, for all data type
>> prop_parse x = x == parse $ display x
> I did merged the existing QuickCheck test cases into one file. I found
> it easier to reuse the generator functions for different types.
> My findings:
>  - The System.Platform did not passed parse tests. The reason: both
> System.OS and System.Arch allowed the dash character in the name. But
> System.Platform text representation was concatenate the two strings
> separated by a dash. So I just simple removed the dash from them.
> Solved! ;)
> - VersionRange does not passes parse tests, iff more than two ranges
> is present. As far as I could see, the parse method is wired to handle
> only two ranges. Not corrected, because found no good solution. Need
> help on this!
> - Package.Dependency also not passes parse tests. (It is depend on
> VersionRange success.)
> - Compat.ReadR gather property is obsolete and does not compile. Can't
> figure it out how could I rewrite it. Need help!
> - PackageDescription does not passes simple parse test. I guess the
> problem is with the test itself! ;) I used showPackageDescription
> method to generate string representation of this type and parse it
> back. I could not judge it is an expected behaviour or a bug. Need
> some explanation.
> My problem is mainly how to run these tests? As unit tests they are
> pure, does not manipulate any files on disks, does not open socket or
> anything. (Michael Feathers use the unit test word as strict as this.)
> So, I expected to run them by anyone, who could compile the sources.
> #1 'cabal test' could be the best way to exercise them. But the user
> hook is so complicated for a simple 'compile and run'. Found others
> ignoring the arguments and call System.Cmd, execute _the compiler_.
> The compiler name is wired and dependencies also not visible enough,
> not to mention the extension handling. Basically compile by hand is
> against cabal! :) (Pro: the best way to invoke; Con: very hard to do)
> #2 Create testing flag in the cabal file, which enable an executable
> to be build. (Xmonad guys doing this way.) It compiles easy, developer
> need not worry about different compilers. Running the test can be done
> by hand (or darcs) or the test user hook can execute it. If the main
> product is a library, then it does not link against that, since the
> library is not installed. Instead developers specify the source dir
> and it recompiles the tested sources. (Pro: easy to do; Cons: does not
> test against library)
> #3 Create another cabal file. Roughly speaking it is same as #2. In my
> opinion it is suite best for functional tests. (Pro: easy to do; Cons:
> testing target must be installed first)
> #4 Use the QuickCheck script. Based naming convention this script runs
> through the sources, 'grep' the properties, and exec an interpreter to
> run them. (Pro: easy; Cons: interpreter name is wired in the script)
> #5 As a proposed long term solution: I might add a new parameter to
> the 'executable' region describe the target is a unit test. Compile
> (and run) it only on 'cabal test' invocation. (Con: It does not exists
> and might be hard to implement :))
> Thanks for any help!
> Regards,
> Laszlo
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