Make library section optional

package.yaml

@@ -1,5 +1,7 @@
 name: cabalize
+
 ghc-options: -Wall
+
 dependencies:
   - aeson >= 0.8
   - base == 4.*
@@ -9,10 +11,16 @@ dependencies:
   - interpolate
   - unordered-containers
   - yaml
+
+library:
+  exposed-modules:
+    - Cabalize
+
 executables:
   cb:
     main: driver/Main.hs
     dependencies: cabalize
+
 tests:
   spec:
     main: test/Spec.hs

src/Cabalize.hs

@@ -59,7 +59,7 @@ version: #{packageVersion}
 build-type: Simple
 cabal-version: >= 1.10
 
-#{renderLibrary packageLibrary}
+#{maybe "" renderLibrary packageLibrary}
 #{renderExecutables packageExecutables}
 #{renderTests packageTests}
 |]
@@ -70,6 +70,8 @@ library
   hs-source-dirs: src
   exposed-modules:
 #{intercalate "\n" . map ("      " ++) $ libraryExposedModules}
+  other-modules:
+#{intercalate "\n" . map ("      " ++) $ libraryOtherModules}
   build-depends:
       #{intercalate "\n    , " $ sort libraryDependencies}
   default-language: Haskell2010

src/Config.hs

@@ -9,6 +9,7 @@ module Config (
 import           Prelude ()
 import           Prelude.Compat
 
+import           Data.List ((\\))
 import           Data.Maybe
 import           Data.Yaml
 import           GHC.Generics
@@ -18,6 +19,15 @@ import           System.Directory
 
 import           Util
 
+data LibrarySection = LibrarySection {
+  librarySectionExposedModules :: Maybe (List Dependency)
+, librarySectionDependencies :: Maybe (List Dependency)
+, librarySectionGhcOptions :: Maybe (List GhcOption)
+} deriving (Eq, Show, Generic)
+
+instance FromJSON LibrarySection where
+  parseJSON = genericParseJSON_ "LibrarySection"
+
 data ExecutableSection = ExecutableSection {
   executableSectionMain :: FilePath
 , executableSectionDependencies :: Maybe (List Dependency)
@@ -32,6 +42,7 @@ data ConfigFile = ConfigFile {
 , configFileVersion :: Maybe String
 , configFileDependencies :: Maybe [Dependency]
 , configFileGhcOptions :: Maybe (List GhcOption)
+, configFileLibrary :: Maybe LibrarySection
 , configFileExecutables :: Maybe (HashMap String ExecutableSection)
 , configFileTests :: Maybe (HashMap String ExecutableSection)
 } deriving (Eq, Show, Generic)
@@ -52,14 +63,16 @@ type GhcOption = String
 data Package = Package {
   packageName :: String
 , packageVersion :: String
-, packageLibrary :: Library
+, packageLibrary :: Maybe Library
 , packageExecutables :: [Executable]
 , packageTests :: [Executable]
 } deriving (Eq, Show)
 
 data Library = Library {
   libraryExposedModules :: [String]
+, libraryOtherModules :: [String]
 , libraryDependencies :: [Dependency]
+, libraryGhcOptions :: [GhcOption]
 } deriving (Eq, Show)
 
 data Executable = Executable {
@@ -73,18 +86,25 @@ mkPackage :: ConfigFile -> IO Package
 mkPackage ConfigFile{..} = do
   let dependencies = fromMaybe [] configFileDependencies
   let ghcOptions = fromMaybeList configFileGhcOptions
-  library <- mkLibrary dependencies
+  mLibrary <- mapM (mkLibrary dependencies ghcOptions) configFileLibrary
   let package = Package {
         packageName = configFileName
       , packageVersion = fromMaybe "0.0.0" configFileVersion
-      , packageLibrary = library
+      , packageLibrary = mLibrary
       , packageExecutables = toExecutables dependencies ghcOptions configFileExecutables
       , packageTests       = toExecutables dependencies ghcOptions configFileTests
       }
   return package
 
-mkLibrary :: [Dependency] -> IO Library
-mkLibrary dependencies = Library <$> getModules "src" <*> pure dependencies
+mkLibrary :: [Dependency] -> [GhcOption] -> LibrarySection -> IO Library
+mkLibrary globalDependencies globalGhcOptions LibrarySection{..} = do
+  modules <- getModules "src"
+  let otherModules = modules \\ exposedModules
+  return (Library exposedModules otherModules dependencies ghcOptions)
+  where
+    exposedModules = fromMaybeList librarySectionExposedModules
+    dependencies = globalDependencies ++ fromMaybeList librarySectionDependencies
+    ghcOptions = globalGhcOptions ++ fromMaybeList librarySectionGhcOptions
 
 getModules :: FilePath -> IO [String]
 getModules src = do

test/ConfigSpec.hs

@@ -11,11 +11,14 @@ main :: IO ()
 main = hspec spec
 
 package :: String -> Package
-package name = Package name "0.0.0" (Library [] []) [] []
+package name = Package name "0.0.0" Nothing [] []
 
 executable :: String -> String -> Executable
 executable name path = Executable name path [] []
 
+library :: Library
+library = Library [] [] [] []
+
 spec :: Spec
 spec = around_ inTempDirectory $ do
   describe "readConfig" $ do
@@ -32,6 +35,17 @@ spec = around_ inTempDirectory $ do
         |]
       readConfig "package.yaml" `shouldReturn` Just (package "foo") {packageVersion = "0.1.0"}
 
+    context "when reading library section" $ do
+      it "allows to specify exposed modules" $ do
+        writeFile "package.yaml" [i|
+          name: foo
+          library:
+            exposed-modules: Foo
+          |]
+        touch "src/Foo.hs"
+        touch "src/Bar.hs"
+        readConfig "package.yaml" `shouldReturn` Just (package "foo") {packageLibrary = Just library {libraryExposedModules = ["Foo"], libraryOtherModules = ["Bar"]}}
+
     context "when reading executable section" $ do
       it "reads executable section" $ do
         writeFile "package.yaml" [i|
@@ -106,4 +120,4 @@ spec = around_ inTempDirectory $ do
                 main: test/Spec.hs
                 dependencies: hspec
             |]
-          readConfig "package.yaml" `shouldReturn` Just (package "foo") {packageTests = [(executable "spec" "test/Spec.hs") {executableDependencies = ["base", "hspec"]}], packageLibrary = Library [] ["base"]}
+          readConfig "package.yaml" `shouldReturn` Just (package "foo") {packageTests = [(executable "spec" "test/Spec.hs") {executableDependencies = ["base", "hspec"]}]}

test/Helper.hs

@@ -2,6 +2,7 @@ module Helper where
 
 import           Control.Exception
 import           System.Directory
+import           System.FilePath
 import           System.IO.Temp
 
 inTempDirectory :: IO a -> IO a
@@ -9,3 +10,8 @@ inTempDirectory action = withSystemTempDirectory "hspec" $ \path -> do
   bracket getCurrentDirectory setCurrentDirectory $ \_ -> do
     setCurrentDirectory path
     action
+
+touch :: FilePath -> IO ()
+touch p = do
+  createDirectoryIfMissing True (takeDirectory p)
+  writeFile p ""