From adfd980a6064b6a44b1435fbf5aa02c06d8380a9 Mon Sep 17 00:00:00 2001
From: Diogo Biazus <diogob@gmail.com>
Date: Tue, 6 Oct 2015 20:27:54 -0400
Subject: [PATCH] Moves minimum pg version to config, eliminates magic constant
 from main and improves docs.

---
 src/PostgREST/Config.hs | 8 +++++++-
 src/PostgREST/Main.hs   | 5 +++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/PostgREST/Config.hs b/src/PostgREST/Config.hs
index 8c762c4f3..a268f1626 100644
--- a/src/PostgREST/Config.hs
+++ b/src/PostgREST/Config.hs
@@ -8,15 +8,17 @@ It also can be used to define other middleware configuration that may be delegat
 external configuration.
 
 It currently includes a hardcoded CORS policy but this could easly be turned in configurable behaviour if needed.
+
+Other hardcoded options such as the minimum version number also belong here.
 -}
 module PostgREST.Config ( prettyVersion
                         , readOptions
                         , corsPolicy
+                        , minimumPgVersion
                         , AppConfig (..)
                         )
        where
 
-
 import           Control.Applicative
 import qualified Data.ByteString.Char8       as BS
 import qualified Data.CaseInsensitive        as CI
@@ -100,3 +102,7 @@ readOptions = customExecParser parserPrefs opts
                     <> " / create a REST API to an existing Postgres database"
                     )
     parserPrefs = prefs showHelpOnError
+
+-- | Tells the minimum PostgreSQL version required by this version of PostgREST
+minimumPgVersion :: Integer
+minimumPgVersion = 90200
diff --git a/src/PostgREST/Main.hs b/src/PostgREST/Main.hs
index a2787f842..2c1567c51 100644
--- a/src/PostgREST/Main.hs
+++ b/src/PostgREST/Main.hs
@@ -26,12 +26,13 @@ import           System.IO                            (BufferMode (..),
 
 import           PostgREST.Config                     (AppConfig (..),
                                                        prettyVersion,
-                                                       readOptions)
+                                                       readOptions,
+                                                       minimumPgVersion)
 
 isServerVersionSupported :: H.Session P.Postgres IO Bool
 isServerVersionSupported = do
   Identity (row :: Text) <- H.tx Nothing $ H.singleEx $ [H.stmt|SHOW server_version_num|]
-  return $ read (cs row) >= (90200::Integer)
+  return $ read (cs row) >= minimumPgVersion
 
 main :: IO ()
 main = do