Refactor the way packages databases are handled

- cradle now stores a list of active package databases instead of only
  the user store (if present).

- rename `cradlePackageDb` -> `cradlePkgDbStack` as that`s what the ghc
  documentaion calls this kind of thing

- `getPackageDbPackages` now returns names of all visible packages in
  the given directory. Also the implementation now uses `ghc-pkg`
  instead of manually looking at the package database

test/CabalApiSpec.hs

@@ -9,6 +9,8 @@ import Language.Haskell.GhcMod.CabalApi
 import Language.Haskell.GhcMod.Cradle
 import Language.Haskell.GhcMod.Types
 import Test.Hspec
+import System.Directory
+import System.FilePath
 
 import Dir
 
@@ -20,6 +22,7 @@ spec = do
 
     describe "getCompilerOptions" $ do
         it "gets necessary CompilerOptions" $ do
+            cwd <- getCurrentDirectory
             withDirectory "test/data/subdir1/subdir2" $ \dir -> do
                 cradle <- findCradle
                 pkgDesc <- parseCabalFile $ fromJust $ cradleCabalFile cradle
@@ -28,7 +31,7 @@ spec = do
                         ghcOptions  = ghcOptions res
                       , includeDirs = map (toRelativeDir dir) (includeDirs res)
                       }
-                res' `shouldBe` CompilerOptions {ghcOptions = ["-no-user-package-db","-package-db","/home/me/work/ghc-mod/test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d","-XHaskell98"], includeDirs = ["test/data","test/data/dist/build","test/data/dist/build/autogen","test/data/subdir1/subdir2","test/data/test"], depPackages = [("Cabal", Nothing), ("base", Nothing) , ("template-haskell", Nothing)]}
+                res' `shouldBe` CompilerOptions {ghcOptions = ["-global-package-db", "-no-user-package-db","-package-db",cwd </> "test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d","-XHaskell98"], includeDirs = ["test/data","test/data/dist/build","test/data/dist/build/autogen","test/data/subdir1/subdir2","test/data/test"], depPackages = [("Cabal", Nothing), ("base", Nothing) , ("template-haskell", Nothing)]}
 
     describe "cabalDependPackages" $ do
         it "extracts dependent packages" $ do

test/CradleSpec.hs

@@ -4,7 +4,7 @@ import Control.Applicative
 import Data.List (isSuffixOf)
 import Language.Haskell.GhcMod.Cradle
 import Language.Haskell.GhcMod.Types
-import System.Directory (canonicalizePath)
+import System.Directory (canonicalizePath,getCurrentDirectory)
 import System.FilePath ((</>), pathSeparator)
 import Test.Hspec
 
@@ -21,17 +21,18 @@ spec = do
                     cradleCurrentDir = curDir
                   , cradleRootDir    = curDir
                   , cradleCabalFile  = Nothing
-                  , cradlePackageDb  = Nothing
+                  , cradlePkgDbStack = [GlobalDb]
                   , cradlePackages   = []
                   }
         it "finds a cabal file and a sandbox" $ do
+            cwd <- getCurrentDirectory
             withDirectory "test/data/subdir1/subdir2" $ \dir -> do
                 res <- relativeCradle dir <$> findCradle
                 res `shouldBe` Cradle {
                     cradleCurrentDir = "test" </> "data" </> "subdir1" </> "subdir2"
                   , cradleRootDir    = "test" </> "data"
                   , cradleCabalFile  = Just ("test" </> "data" </> "cabalapi.cabal")
-                  , cradlePackageDb  = Just ("test" </> "data" </> ".cabal-sandbox" </> "/home/me/work/ghc-mod/test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d")
+                  , cradlePkgDbStack = [GlobalDb, PackageDb (cwd </> "test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d")]
                   , cradlePackages   = []
                   }
         it "works even if a sandbox config file is broken" $ do
@@ -41,23 +42,10 @@ spec = do
                     cradleCurrentDir = "test" </> "data" </> "broken-sandbox"
                   , cradleRootDir    = "test" </> "data" </> "broken-sandbox"
                   , cradleCabalFile  = Just ("test" </> "data" </> "broken-sandbox" </> "dummy.cabal")
-                  , cradlePackageDb  = Nothing
+                  , cradlePkgDbStack = [GlobalDb, UserDb]
                   , cradlePackages   = []
                   }
 
-    describe "getPackageDbDir" $ do
-        it "parses a config file and extracts package db" $ do
-            pkgDb <- getPackageDbDir "test/data/cabal.sandbox.config"
-            pkgDb `shouldBe` "/home/me/work/ghc-mod/test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d"
-
-        it "throws an error if a config file is broken" $ do
-            getPackageDbDir "test/data/bad.config" `shouldThrow` anyException
-
-    describe "getPackageDbPackages" $ do
-        it "find a config file and extracts packages with their ids" $ do
-            pkgs <- getPackageDbPackages "test/data/check-packageid"
-            pkgs `shouldBe` [("template-haskell", Just "template-haskell-2.8.0.0-32d4f24abdbb6bf41272b183b2e23e9c")]
-
 relativeCradle :: FilePath -> Cradle -> Cradle
 relativeCradle dir cradle = cradle {
     cradleCurrentDir    = toRelativeDir dir  $  cradleCurrentDir cradle

test/GhcPkgSpec.hs

@@ -0,0 +1,27 @@
+module GhcPkgSpec where
+
+import Language.Haskell.GhcMod.Types
+import Language.Haskell.GhcMod.GhcPkg
+
+import Control.Applicative
+import System.Directory
+import System.FilePath ((</>))
+import Test.Hspec
+
+import Dir
+
+spec :: Spec
+spec = do
+    describe "getSandboxDb" $ do
+        it "parses a config file and extracts sandbox package db" $ do
+            cwd <- getCurrentDirectory
+            pkgDb <- getSandboxDb "test/data/"
+            pkgDb `shouldBe` (cwd </> "test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d")
+
+        it "throws an error if a config file is broken" $ do
+            getSandboxDb "test/data/broken-sandbox" `shouldThrow` anyException
+
+    describe "getPackageDbPackages" $ do
+        it "find a config file and extracts packages" $ do
+            pkgs <- getPackageDbPackages "test/data/check-packageid"
+            pkgs `shouldSatisfy` (\x -> length x >= 1)

test/Main.hs

@@ -0,0 +1,12 @@
+import Spec
+import Dir
+
+import Test.Hspec
+import System.Process
+
+main = do
+  let sandboxes = [ "test/data", "test/data/check-packageid" ]
+      genSandboxCfg dir = withDirectory dir $ \cwd -> do
+         system ("sed 's|@CWD@|" ++ cwd ++ "|g' cabal.sandbox.config.in > cabal.sandbox.config")
+  genSandboxCfg `mapM` sandboxes
+  hspec spec

test/Spec.hs

@@ -1 +1 @@
-{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
+{-# OPTIONS_GHC -F -pgmF hspec-discover -optF --no-main #-}

test/data/cabal.sandbox.config.in

@@ -4,15 +4,15 @@
 -- if you want to change the default settings for this sandbox.
 
 
-local-repo: /home/me/work/ghc-mod/test/data/.cabal-sandbox/packages
-logs-dir: /home/me/work/ghc-mod/test/data/.cabal-sandbox/logs
-world-file: /home/me/work/ghc-mod/test/data/.cabal-sandbox/world
+local-repo: @CWD@/test/data/.cabal-sandbox/packages
+logs-dir: @CWD@/test/data/.cabal-sandbox/logs
+world-file: @CWD@/test/data/.cabal-sandbox/world
 user-install: False
-package-db: /home/me/work/ghc-mod/test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d
-build-summary: /home/me/work/ghc-mod/test/data/.cabal-sandbox/logs/build.log
+package-db: @CWD@/test/data/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d
+build-summary: @CWD@/test/data/.cabal-sandbox/logs/build.log
 
-install-dirs 
-  prefix: /home/me/work/ghc-mod/test/data/.cabal-sandbox
+install-dirs
+  prefix: @CWD@/test/data/.cabal-sandbox
   bindir: $prefix/bin
   libdir: $prefix/lib
   libsubdir: $arch-$os-$compiler/$pkgid

test/data/check-packageid/cabal.sandbox.config.in

@@ -4,15 +4,15 @@
 -- if you want to change the default settings for this sandbox.
 
 
-local-repo: /home/me/work/ghc-mod/test/data/.cabal-sandbox/packages
-logs-dir: /home/me/work/ghc-mod/test/data/.cabal-sandbox/logs
-world-file: /home/me/work/ghc-mod/test/data/.cabal-sandbox/world
+local-repo: @CWD@/test/data/.cabal-sandbox/packages
+logs-dir: @CWD@/test/data/.cabal-sandbox/logs
+world-file: @CWD@/test/data/.cabal-sandbox/world
 user-install: False
 package-db: test/data/check-packageid/.cabal-sandbox/i386-osx-ghc-7.6.3-packages.conf.d
-build-summary: /home/me/work/ghc-mod/test/data/.cabal-sandbox/logs/build.log
+build-summary: @CWD@/test/data/.cabal-sandbox/logs/build.log
 
-install-dirs 
-  prefix: /home/me/work/ghc-mod/test/data/.cabal-sandbox
+install-dirs
+  prefix: @CWD@/test/data/.cabal-sandbox
   bindir: $prefix/bin
   libdir: $prefix/lib
   libsubdir: $arch-$os-$compiler/$pkgid