Moves all config related code to PostgREST.Config module and

tweak the code to better encapsulate functionality.

postgrest.cabal

@@ -94,6 +94,7 @@ library
                      , errors
                      , bifunctors
 
+  Other-Modules:       Paths_postgrest
   Exposed-Modules:     PostgREST.App
                      , PostgREST.Types
                      , PostgREST.Parsers
@@ -130,6 +131,7 @@ Test-Suite spec
                      , PostgREST.RangeQuery
                      , Spec
                      , SpecHelper
+                     , Paths_postgrest
   Build-Depends:       base, hspec == 2.1.*, QuickCheck
                      , hspec-wai, hspec-wai-json
                      , hasql, hasql-backend

src/PostgREST/Config.hs

@@ -1,14 +1,22 @@
-module PostgREST.Config where
+module PostgREST.Config ( prettyVersion
+                        , readOptions
+                        , corsPolicy
+                        , AppConfig (..)
+                        )
+       where
 
 
 import           Control.Applicative
 import qualified Data.ByteString.Char8       as BS
 import qualified Data.CaseInsensitive        as CI
+import           Data.List                   (intercalate)
 import           Data.String.Conversions     (cs)
 import           Data.Text                   (strip)
+import           Data.Version                (versionBranch)
 import           Network.Wai
 import           Network.Wai.Middleware.Cors (CorsResourcePolicy (..))
 import           Options.Applicative         hiding (columns)
+import           Paths_postgrest             (version)
 import           Prelude
 
 data AppConfig = AppConfig {
@@ -63,3 +71,18 @@ corsPolicy req = case lookup "origin" headers of
     accHeaders = case lookup "access-control-request-headers" headers of
       Just hdrs -> map (CI.mk . cs . strip . cs) $ BS.split ',' hdrs
       Nothing -> []
+
+prettyVersion :: String
+prettyVersion = intercalate "." $ map show $ versionBranch version
+
+readOptions :: IO AppConfig
+readOptions = customExecParser parserPrefs opts
+  where
+    opts = info (helper <*> argParser) $
+                    fullDesc
+                    <> progDesc (
+                    "PostgREST "
+                    <> prettyVersion
+                    <> " / create a REST API to an existing Postgres database"
+                    )
+    parserPrefs = prefs showHelpOnError

src/PostgREST/Main.hs

@@ -1,7 +1,6 @@
 module Main where
 
 
-import           Paths_postgrest                      (version)
 import           PostgREST.PgStructure
 import           PostgREST.Types
 import           Network.Wai
@@ -13,22 +12,21 @@ import           PostgREST.Middleware
 import           Control.Monad                        (unless)
 import           Control.Monad.IO.Class               (liftIO)
 import           Data.Functor.Identity
-import           Data.List                            (intercalate)
-import           Data.String.Conversions              (cs)
+import           Data.String.Conversions              (cs,
+                                                       (<>))
 import           Data.Text                            (Text)
-import           Data.Version                         (versionBranch)
 import qualified Hasql                                as H
 import qualified Hasql.Postgres                       as P
 import           Network.Wai.Handler.Warp             hiding (Connection)
 import           Network.Wai.Middleware.RequestLogger (logStdout)
-import           Options.Applicative                  hiding (columns)
 
 import           System.IO                            (BufferMode (..),
                                                        hSetBuffering, stderr,
                                                        stdin, stdout)
 
 import           PostgREST.Config                     (AppConfig (..),
-                                                       argParser)
+                                                       prettyVersion,
+                                                       readOptions)
 
 isServerVersionSupported :: H.Session P.Postgres IO Bool
 isServerVersionSupported = do
@@ -41,15 +39,7 @@ main = do
   hSetBuffering stdin  LineBuffering
   hSetBuffering stderr NoBuffering
 
-  let opts = info (helper <*> argParser) $
-               fullDesc
-               <> progDesc (
-                 "PostgREST "
-                 <> prettyVersion
-                 <> " / create a REST API to an existing Postgres database"
-               )
-      parserPrefs = prefs showHelpOnError
-  conf <- customExecParser parserPrefs opts
+  conf <- readOptions
   let port = configPort conf
 
   unless (configSecure conf) $
@@ -104,6 +94,3 @@ main = do
     resOrError <- liftIO $ H.session pool $ H.tx txSettings $
       authenticated conf (app dbstructure conf body) req
     either (respond . errResponse) respond resOrError
-
-  where
-    prettyVersion = intercalate "." $ map show $ versionBranch version