From df30f9def5555858c046946dcff3111b50468086 Mon Sep 17 00:00:00 2001
From: ALeX Kazik <git@kazik.de>
Date: Thu, 27 Dec 2018 17:15:09 +0100
Subject: [PATCH] Add pedantic option to ghci (#4463)

---
 ChangeLog.md                    |  2 ++
 src/Stack/Options/GhciParser.hs | 11 ++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index d9bd16a3c2..0943509888 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -77,6 +77,8 @@ Other enhancements:
   [#4095](https://github.com/commercialhaskell/stack/issues/4095)
 * Add `--tree` to `ls dependencies` to list dependencies as tree.
   [#4101](https://github.com/commercialhaskell/stack/issues/4101)
+* Add `--pedantic` to `ghci` to run with `-Wall` and `-Werror`
+  [#4463](https://github.com/commercialhaskell/stack/issues/4463)
 
 Bug fixes:
 
diff --git a/src/Stack/Options/GhciParser.hs b/src/Stack/Options/GhciParser.hs
index e28249ae66..e482b5d320 100644
--- a/src/Stack/Options/GhciParser.hs
+++ b/src/Stack/Options/GhciParser.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE NoImplicitPrelude #-}
+{-# LANGUAGE OverloadedStrings #-}
 module Stack.Options.GhciParser where
 
 import           Options.Applicative
@@ -27,12 +28,20 @@ ghciOptsParser = GhciOpts
                                     metavar "OPTIONS" <>
                                     completer ghcOptsCompleter <>
                                     help "Additional options passed to GHCi")))
-             <*> many
+
+             <*> (
+                 (\x y -> x ++ y)
+                 <$> flag
+                     []
+                     ["-Wall", "-Werror"]
+                     (long "pedantic" <> help "Turn on -Wall and -Werror")
+                 <*> many
                      (textOption
                           (long "ghc-options" <>
                            metavar "OPTIONS" <>
                            completer ghcOptsCompleter <>
                            help "Additional options passed to both GHC and GHCi"))
+             )
              <*> flagsParser
              <*> optional
                      (strOption (long "with-ghc" <>