Add test for #10717

The test checks that if you change directory when running a test
executable that you can still access datafiles.

Author: mpickering

cabal-testsuite/PackageTests/DataDirSetupTest/Setup.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain

cabal-testsuite/PackageTests/DataDirSetupTest/cabal.test.hs

@@ -0,0 +1,5 @@
+import Test.Cabal.Prelude
+
+main = setupAndCabalTest $ do
+    setup_build ["--enable-tests"]
+    setup "test" ["--show-details=streaming"]

cabal-testsuite/PackageTests/DataDirSetupTest/datadir-test.cabal

@@ -0,0 +1,27 @@
+cabal-version:      2.4
+name:               datadir-test
+version:            0.1.0.0
+synopsis:           Test for datadir environment variable
+license:            BSD-3-Clause
+author:             Cabal Test Suite
+maintainer:         [email protected]
+build-type:         Simple
+
+data-files:
+    testdata/sample.txt
+
+library
+    exposed-modules:     MyLib
+    build-depends:       base >=4.7 && <5
+    other-modules: Paths_datadir_test
+    hs-source-dirs:      src
+    default-language:    Haskell2010
+
+test-suite datadir-test
+    type:               exitcode-stdio-1.0
+    main-is:            DataDirTest.hs
+    hs-source-dirs:     test
+    build-depends:      base >=4.7 && <5,
+                        datadir-test,
+                        directory
+    default-language:   Haskell2010

cabal-testsuite/PackageTests/DataDirSetupTest/src/MyLib.hs

@@ -0,0 +1,6 @@
+module MyLib (getDataFileName) where
+
+import qualified Paths_datadir_test as Paths
+
+getDataFileName :: FilePath -> IO FilePath
+getDataFileName = Paths.getDataFileName

cabal-testsuite/PackageTests/DataDirSetupTest/test/DataDirTest.hs

@@ -0,0 +1,48 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+module Main where
+
+import Control.Monad (when)
+import System.Directory (createDirectory, doesFileExist, getCurrentDirectory, setCurrentDirectory)
+import System.Environment (getEnv)
+import System.Exit (exitFailure, exitSuccess)
+import System.IO (hPutStrLn, stderr)
+import MyLib (getDataFileName)
+import Control.Exception
+
+main :: IO ()
+main = do
+    -- Print the datadir environment variable
+    dataDirEnv <- getEnv "datadir_test_datadir"
+    putStrLn $ "datadir_test_datadir: " ++ dataDirEnv
+
+    -- Get path to our test data file
+    dataFilePath <- getDataFileName "testdata/sample.txt"
+    putStrLn $ "Data file path: " ++ dataFilePath
+
+    -- Check that we can access the file
+    fileExists <- doesFileExist dataFilePath
+    putStrLn $ "File exists: " ++ show fileExists
+
+    -- Create a subdirectory and change into it
+    currentDir <- getCurrentDirectory
+    putStrLn $ "Current directory: " ++ currentDir
+    createDirectory "subdir" `catch` \(_ :: SomeException) -> pure ()
+    setCurrentDirectory "subdir"
+    newDir <- getCurrentDirectory
+    putStrLn $ "New directory: " ++ newDir
+
+    -- Try to access the data file again after changing directory
+    dataFilePathAfterCd <- getDataFileName "testdata/sample.txt"
+    putStrLn $ "Data file path after cd: " ++ dataFilePathAfterCd
+
+    fileExistsAfterCd <- doesFileExist dataFilePathAfterCd
+    putStrLn $ "File exists after cd: " ++ show fileExistsAfterCd
+
+    -- Exit with error if we can't find the file
+    when (not fileExistsAfterCd) $ do
+        hPutStrLn stderr "ERROR: Could not find data file after changing directory!"
+        hPutStrLn stderr $ "datadir_test_datadir was set to: " ++ dataDirEnv
+        exitFailure
+
+    putStrLn "SUCCESS: Data file found correctly even after changing directory!"
+    exitSuccess

cabal-testsuite/PackageTests/DataDirSetupTest/testdata/sample.txt

@@ -0,0 +1 @@
+This is test data for the datadir test.