How to install library with tests

[ivanperez-keera]

I'm using GHC 9.4.8 and cabal 3.8.

I'm trying to install copilot-language-3.17 from hackage with tests.

The obvious way cabal install copilot-language --enable-tests results in an error message:

Error: cabal: --enable-tests was specified, but tests can't be enabled in a remote package

What is currently the way to install a package with tests enabled?

[Mikolaj]

I think you can't. I'm not sure why. Perhaps because tests are permitted to assume they are run in a checked in repo, with data files at the repo location, not the installed location, etc.

I imagine cabal get foo; unpack; cabal test might work, if there's enough of the repo contained in the Hackage package.

Or, if the test is self-contained, standalone and user-facing, perhaps turn it into an executable component, for the user to install and run.

[Mikolaj]

for the user to install and run.

Actually, don't install, just run (cabal run). But you probably want to test the library you installed. I'm afraid, regardless if that's cabal install or cabal run, the executable will not use the installed library, but will have a library statically linked in. I think that's the case with tests, too. Unless you use v1-test, if that's a thing. Or if the executable is in another package and built with v1.

BTW, the commandline you provided won't install the library. It's only used to install executables. You probably want --lib or cabal-env (or v1, but it's mostly unmaintained) or a makefile or a shell script (which can also ensure tests are built against the installed library).

[mpickering]

Do you want to run the tests during the install process or also install the test executables?

[ivanperez-keera]

I want to make sure I run the tests.

Ideally, I'd like to do what used to happen with:

$ cabal v1-install --enable-tests --only-dependencies
$ cabal v1-test

[gbaz]

I think this would need to be a feature request for v2-install that it have a flag to run test-suites as part of installation -- I don't see another way for this to work exactly as desired.

note that even in v1-install this didn't actually occur -- rather, the tests would get run on the downloaded package and entirely independently the package would get installed -- it would just so happen that produced binary artifacts would be reused between the two. the equivalent in v2 is what mikolaj suggested -- cabal get foo; unpack; cabal test; cabal install;. This sequence just makes it more explicit that the testing and the installation are actually independent.

[ulysses4ever]

Relevant prior discussion:

• cabal v2-install ignores flag --run-tests #7267

[ivanperez-keera]

Running cabal test results in:

Resolving dependencies...
No tests to run for the package copilot-libraries-3.17

[gbaz]

right. copilot-libraries doesn't have any tests. its also a library and not an executable.

is the ask that i can cabal v2-install lib foo and then all dependencies of foo have their tests run?

[ivanperez-keera]

copilot-libraries doesn't have any tests

I'm an idiot and you're right. I meant to try copilot-language. That one I cannot install with cabal install --only-dependencies --enable-tests, but I can test with cabal test.