Tests: factor out setupEnvironment in Test.Helpers.

This avoids code duplication between Command and Old.

test/Tests/Command.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE TupleSections #-}
 {- |
    Module      : Tests.Command
    Copyright   : © 2006-2021 John MacFarlane
@@ -19,9 +18,8 @@ import qualified Data.ByteString as BS
 import qualified Data.Text as T
 import Data.List (isSuffixOf)
 import System.Directory
-import qualified System.Environment as Env
 import System.Exit
-import System.FilePath (takeDirectory, (</>))
+import System.FilePath ((</>))
 import System.IO (hPutStr, stderr)
 import System.IO.Unsafe (unsafePerformIO)
 import System.Process
@@ -38,16 +36,7 @@ execTest :: String    -- ^ Path to test executable
          -> String    -- ^ Input text
          -> IO (ExitCode, String)  -- ^ Exit code and actual output
 execTest testExePath cmd inp = do
-  mldpath   <- Env.lookupEnv "LD_LIBRARY_PATH"
-  mdyldpath <- Env.lookupEnv "DYLD_LIBRARY_PATH"
-  mpdd <- Env.lookupEnv "pandoc_datadir"
-  let env' = ("PATH",takeDirectory testExePath) :
-             ("TMP",".") :
-             ("LANG","en_US.UTF-8") :
-             ("HOME", "./") :
-             maybe [] ((:[]) . ("pandoc_datadir",)) mpdd ++
-             maybe [] ((:[]) . ("LD_LIBRARY_PATH",)) mldpath ++
-             maybe [] ((:[]) . ("DYLD_LIBRARY_PATH",)) mdyldpath
+  env' <- setupEnvironment testExePath
   let pr = (shell (pandocToEmulate True cmd)){ env = Just env' }
   (ec, out', err') <- readCreateProcessWithExitCode pr inp
   -- filter \r so the tests will work on Windows machines

test/Tests/Helpers.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE TupleSections #-}
 {-# LANGUAGE FlexibleInstances    #-}
 {- |
    Module      : Tests.Helpers
@@ -13,6 +14,7 @@ Utility functions for the test suite.
 -}
 module Tests.Helpers ( test
                      , TestResult(..)
+                     , setupEnvironment
                      , showDiff
                      , (=?>)
                      , purely
@@ -25,6 +27,8 @@ import Data.Algorithm.Diff
 import qualified Data.Map as M
 import Data.Text (Text, unpack)
 import System.Exit
+import System.FilePath (takeDirectory)
+import qualified System.Environment as Env
 import Test.Tasty
 import Test.Tasty.HUnit
 import Text.Pandoc.Builder (Blocks, Inlines, doc, plain)
@@ -57,6 +61,25 @@ test fn name (input, expected) =
            dashes "" = replicate 72 '-'
            dashes x  = replicate (72 - length x - 5) '-' ++ " " ++ x ++ " ---"
 
+-- | Set up environment for pandoc command tests.
+setupEnvironment :: FilePath -> IO [(String, String)]
+setupEnvironment testExePath = do
+  mldpath   <- Env.lookupEnv "LD_LIBRARY_PATH"
+  mdyldpath <- Env.lookupEnv "DYLD_LIBRARY_PATH"
+  mpdd <- Env.lookupEnv "pandoc_datadir"
+  -- Note that Cabal sets the pandoc_datadir environment variable
+  -- to point to the source directory, since otherwise getDataFilename
+  -- will look in the data directory into which pandoc will be installed
+  -- (but has not yet been).  So when we spawn a new process with
+  -- pandoc, we need to make sure this environment variable is set.
+  return $ ("PATH",takeDirectory testExePath) :
+           ("TMP",".") :
+           ("LANG","en_US.UTF-8") :
+           ("HOME", "./") :
+           maybe [] ((:[]) . ("pandoc_datadir",)) mpdd ++
+           maybe [] ((:[]) . ("LD_LIBRARY_PATH",)) mldpath ++
+           maybe [] ((:[]) . ("DYLD_LIBRARY_PATH",)) mdyldpath
+
 data TestResult = TestPassed
                 | TestError ExitCode
                 | TestFailed String FilePath [Diff String]

test/Tests/Old.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE TupleSections #-}
 {- |
    Module      : Tests.Old
    Copyright   : © 2006-2021 John MacFarlane
@@ -15,7 +14,6 @@ module Tests.Old (tests) where
 import Data.Algorithm.Diff
 import System.Exit
 import System.FilePath ((<.>), (</>))
-import qualified System.Environment as Env
 import System.Environment.Executable (getExecutablePath)
 import Text.Pandoc.Process (pipeProcess)
 import Test.Tasty (TestTree, testGroup)
@@ -319,16 +317,7 @@ testWithNormalize normalizer pandocPath testname opts inp norm =
     (compareValues norm options) updateGolden
   where getExpected = normalizer <$> readFile' norm
         getActual   = do
-              mldpath   <- Env.lookupEnv "LD_LIBRARY_PATH"
-              mdyldpath <- Env.lookupEnv "DYLD_LIBRARY_PATH"
-              mpdd <- Env.lookupEnv "pandoc_datadir"
-              let env  = ("TMP",".") :
-                         ("LANG","en_US.UTF-8") :
-                         ("HOME", "./") :
-                         maybe [] ((:[]) . ("pandoc_datadir",)) mpdd ++
-                         maybe [] ((:[]) . ("LD_LIBRARY_PATH",)) mldpath ++
-                         maybe [] ((:[]) . ("DYLD_LIBRARY_PATH",)) mdyldpath
-
+              env <- setupEnvironment pandocPath
               (ec, out) <- pipeProcess (Just env) pandocPath
                              ("--emulate":options) mempty
               if ec == ExitSuccess