tests: Add a cabal new-build project

Author: rvl

test/shell-for/cabal.project

@@ -0,0 +1,2 @@
+packages: pkga
+          pkgb

test/shell-for/pkga/PkgA.hs

@@ -0,0 +1,16 @@
+module PkgA (decode) where
+
+import Control.Lens
+import Data.Text.Lens
+import Data.Char
+import Data.Text (Text)
+
+decode :: Text -> Text
+decode = unpacked . mapped %~ rot 13
+
+rot :: Int -> Char -> Char
+rot n c | c >= 'a' && c <= 'z' = r 'a' 'z'
+        | c >= 'A' && c <= 'Z' = r 'A' 'Z'
+        | otherwise            = c
+  where
+    r a b = chr $ ord a + ((ord c - ord a + n) `mod` (ord b - ord a + 1))

test/shell-for/pkga/Setup.hs

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

test/shell-for/pkga/pkga.cabal

@@ -0,0 +1,20 @@
+cabal-version:       2.2
+-- Initial package description 'pkga.cabal' generated by 'cabal init'.  For
+--  further documentation, see http://haskell.org/cabal/users-guide/
+
+name:                pkga
+version:             0.1.0.0
+-- synopsis:
+-- description:
+-- bug-reports:
+license:             LicenseRef-PublicDomain
+author:              Rodney Lorrimar
+maintainer:          [email protected]
+category:            Testing
+
+library
+  exposed-modules:     PkgA
+  build-depends:       base
+                     , lens
+                     , text
+  default-language:    Haskell2010

test/shell-for/pkgb/Setup.hs

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

test/shell-for/pkgb/app/Main.hs

@@ -0,0 +1,10 @@
+module Main where
+
+import ConduitExample (example)
+import PkgB (message)
+import qualified Data.Text.IO as T
+
+main :: IO ()
+main = do
+  T.putStrLn message
+  example

test/shell-for/pkgb/pkgb.cabal

@@ -0,0 +1,36 @@
+cabal-version:       2.2
+-- Initial package description 'pkgb.cabal' generated by 'cabal init'.  For
+--  further documentation, see http://haskell.org/cabal/users-guide/
+
+name:                pkgb
+version:             0.1.0.0
+-- synopsis:
+-- description:
+-- bug-reports:
+license:             LicenseRef-PublicDomain
+author:              Rodney Lorrimar
+maintainer:          [email protected]
+category:            Testing
+
+library
+  exposed-modules:     ConduitExample
+                     , PkgB
+  build-depends:       base
+                     , pkga
+                     , conduit
+                     , conduit-extra
+                     , directory
+                     , resourcet
+  hs-source-dirs:      src
+  default-language:    Haskell2010
+
+executable pkgb
+  main-is:             Main.hs
+  -- other-modules:
+  -- other-extensions:
+  build-depends:       base
+                     , pkgb
+                     , optparse-applicative
+                     , text
+  hs-source-dirs:      app
+  default-language:    Haskell2010

test/shell-for/pkgb/src/ConduitExample.hs

@@ -0,0 +1,21 @@
+-- https://github.com/snoyberg/conduit#readme
+
+module ConduitExample (example) where
+
+import Conduit
+import System.Directory (removeFile)
+
+example = do
+    -- Pure operations: summing numbers.
+    print $ runConduitPure $ yieldMany [1..10] .| sumC
+
+    -- Exception safe file access: copy a file.
+    writeFile "input.txt" "This is a test." -- create the source file
+    runConduitRes $ sourceFileBS "input.txt" .| sinkFile "output.txt" -- actual copying
+    readFile "output.txt" >>= putStrLn -- prove that it worked
+
+    -- Perform transformations.
+    print $ runConduitPure $ yieldMany [1..10] .| mapC (+ 1) .| sinkList
+
+    removeFile "input.txt"
+    removeFile "output.txt"

test/shell-for/pkgb/src/PkgB.hs

@@ -0,0 +1,7 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module PkgB (message) where
+
+import PkgA (decode)
+
+message = decode "Guvf vf n pnony cebwrpg!"

test/shell-for/pkgb/src/conduit.hs

@@ -0,0 +1,5 @@
+module Main where
+
+import ConduitExample
+
+main = example

test/tests.sh

@@ -61,4 +61,11 @@ nix-shell $NIX_BUILD_ARGS \
     --run 'cd shell-for && runghc conduit.hs'
 echo >& 2
 
+printf "*** Checking shellFor works for a cabal project...\n" >& 2
+nix-shell $NIX_BUILD_ARGS \
+    --pure ./default.nix \
+    -A shell-for.env.cabal \
+    --run 'cd shell-for && cabal new-build all'
+echo >& 2
+
 printf "\n*** Finished successfully\n" >& 2