From 5c7c28060c65435ef87f0bf1ce5c689f548ee41d Mon Sep 17 00:00:00 2001
From: Tony Zorman <soliditsallgood@mailbox.org>
Date: Fri, 18 Nov 2022 19:17:04 +0100
Subject: [PATCH] ci: Drop support for GHC 8.4

Debian stable is not on 8.6, which was always our guide as to which GHC
versions we want to support.

In particular, this lets us get rid of all the quickcheck-classes
special treatment.

Related: https://github.com/xmonad/xmonad/commit/400730fe3b8aab8e7f9403215c88b37e44fe7a66
---
 .github/workflows/haskell-ci.yml |  5 -----
 .github/workflows/stack.yml      |  1 -
 CHANGES.md                       |  2 ++
 stack.yaml                       |  7 -------
 tests/Properties/Stack.hs        | 10 ----------
 xmonad.cabal                     | 14 ++++----------
 6 files changed, 6 insertions(+), 33 deletions(-)

diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 2715295..1b54726 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -66,11 +66,6 @@ jobs:
             compilerVersion: 8.6.5
             setup-method: hvr-ppa
             allow-failure: false
-          - compiler: ghc-8.4.4
-            compilerKind: ghc
-            compilerVersion: 8.4.4
-            setup-method: hvr-ppa
-            allow-failure: false
       fail-fast: false
     steps:
       - name: apt
diff --git a/.github/workflows/stack.yml b/.github/workflows/stack.yml
index e169cd4..36bdcd1 100644
--- a/.github/workflows/stack.yml
+++ b/.github/workflows/stack.yml
@@ -12,7 +12,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - resolver: lts-12  # GHC 8.4
           - resolver: lts-14  # GHC 8.6
           - resolver: lts-16  # GHC 8.8
           - resolver: lts-18  # GHC 8.10
diff --git a/CHANGES.md b/CHANGES.md
index 5da39ae..f26f2a6 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,8 @@
 
 ### Breaking Changes
 
+* Dropped support for GHC 8.4.
+
 ### Enhancements
 
 * Exported `sendRestart` and `sendReplace` from `XMonad.Operations`.
diff --git a/stack.yaml b/stack.yaml
index 2ec4a08..99ffada 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -6,13 +6,6 @@ packages:
 extra-deps:
 - X11-1.10
 
-flags:
-  xmonad:
-    # stack doesn't support automatic flags
-    # https://cabal.readthedocs.io/en/latest/cabal-package.html#resolution-of-conditions-and-flags
-    # https://github.com/commercialhaskell/stack/issues/1313#issuecomment-157259270
-    quickcheck-classes: false
-
 nix:
   packages:
     - zlib
diff --git a/tests/Properties/Stack.hs b/tests/Properties/Stack.hs
index f85ca3e..a833ce1 100644
--- a/tests/Properties/Stack.hs
+++ b/tests/Properties/Stack.hs
@@ -1,9 +1,5 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-
-#ifdef VERSION_quickcheck_classes
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-#endif
 
 module Properties.Stack where
 
@@ -15,13 +11,11 @@ import qualified XMonad.StackSet as S (filter)
 
 import Data.Maybe
 
-#ifdef VERSION_quickcheck_classes
 import Data.Proxy
 import Test.QuickCheck.Classes (
     Laws (lawsTypeclass, lawsProperties), Proxy1 (Proxy1),
     foldableLaws, traversableLaws,
     )
-#endif
 
 
 -- The list returned by index should be the same length as the actual
@@ -65,7 +59,6 @@ prop_differentiate xs =
     where _ = xs :: [Int]
 
 
-#ifdef VERSION_quickcheck_classes
 -- Check type class laws of 'Data.Foldable.Foldable' and 'Data.Traversable.Traversable'.
 newtype TestStack a = TestStack (Stack a)
     deriving (Eq, Read, Show, Foldable, Functor)
@@ -82,6 +75,3 @@ prop_laws_Stack = format (foldableLaws p) <> format (traversableLaws p)
     p = Proxy :: Proxy TestStack
     format laws = [ ("Stack: " <> lawsTypeclass laws <> ": " <> name, prop)
                   | (name, prop) <- lawsProperties laws ]
-#else
-prop_laws_Stack = []
-#endif
diff --git a/xmonad.cabal b/xmonad.cabal
index da24c52..a26797b 100644
--- a/xmonad.cabal
+++ b/xmonad.cabal
@@ -27,7 +27,7 @@ author:             Spencer Janssen, Don Stewart, Adam Vogt, David Roundy, Jason
                     Ondřej Súkup, Paul Hebble, Shachaf Ben-Kiki, Siim Põder, Tim McIver,
                     Trevor Elliott, Wouter Swierstra, Conrad Irwin, Tim Thelion, Tony Zorman
 maintainer:         xmonad@haskell.org
-tested-with:        GHC == 8.4.4 || == 8.6.5 || == 8.8.4 || == 8.10.7 || == 9.0.2 || == 9.2.5 || == 9.4.2
+tested-with:        GHC == 8.6.5 || == 8.8.4 || == 8.10.7 || == 9.0.2 || == 9.2.5 || == 9.4.2
 category:           System
 homepage:           http://xmonad.org
 bug-reports:        https://github.com/xmonad/xmonad/issues
@@ -54,8 +54,6 @@ flag pedantic
   default:     False
   manual:      True
 
-flag quickcheck-classes
-
 library
   exposed-modules: XMonad
                    XMonad.Config
@@ -83,7 +81,7 @@ library
   default-language: Haskell2010
 
   -- Keep this in sync with the oldest version in 'tested-with'
-  if impl(ghc > 8.4.4)
+  if impl(ghc > 8.6.5)
     ghc-options:   -Wno-unused-imports
 
   if flag(pedantic)
@@ -96,7 +94,7 @@ executable xmonad
   default-language: Haskell2010
 
   -- Keep this in sync with the oldest version in 'tested-with'
-  if impl(ghc > 8.4.4)
+  if impl(ghc > 8.6.5)
     ghc-options:   -Wno-unused-imports
 
   if flag(pedantic)
@@ -125,15 +123,11 @@ test-suite properties
   hs-source-dirs: tests
   build-depends:  base
                 , QuickCheck >= 2
+                , quickcheck-classes >= 0.4.3
                 , X11
                 , containers
                 , xmonad
   default-language: Haskell2010
 
-  if flag(quickcheck-classes) && impl(ghc > 8.5)
-    -- no quickcheck-classes in LTS-12
-    -- GHC 8.4 and lower needs too much boilerplate (Eq1, Show1, …)
-    build-depends: quickcheck-classes >= 0.4.3
-
   if flag(pedantic)
     ghc-options:   -Werror