Each test is a shell script. Tests that share files (e.g., .cabal files) are
grouped under a common sub-directory of IntegrationTests. The framework
copies the whole group's directory before running each test, which allows tests
to reuse files, yet run independently. A group's tests are further divided into
should_run and should_fail directories, based on the expected exit status.
For example, the test
IntegrationTests/exec/should_fail/exit_with_failure_without_args.sh has access
to all files under exec and is expected to fail.
Tests can specify their expected output. For a test named x.sh, x.out
specifies stdout and x.err specifies stderr. Both files are optional.
The framework expects an exact match between lines in the file and output,
except for lines beginning with "RE:", which are interpreted as regular
expressions.
IntegrationTests.hs defines several environment variables:
CABAL - The path to the executable being tested.GHC_PKG - The path to ghc-pkg.CABAL_ARGS - A common set of arguments for running cabal.CABAL_ARGS_NO_CONFIG_FILE - CABAL_ARGS without --config-file.