From c87d14a770c99ae9c01cb019a8134edf31944bce Mon Sep 17 00:00:00 2001
From: Malte Brandy <malte.brandy@maralorn.de>
Date: Sat, 5 Feb 2022 03:13:24 +0100
Subject: [PATCH] haskell.packages.ghc902.haskell-language-server: Enable all
 working plugins

---
 .../configuration-ghc-9.0.x.nix               | 17 +++-------
 .../configuration-hackage2nix/main.yaml       |  1 +
 .../haskell-modules/hackage-packages.nix      | 34 +++++++++++++++++++
 3 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix b/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix
index 819b8655f5e2..c628fe95f7c5 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix
@@ -150,23 +150,14 @@ self: super: {
   # Fixes a bug triggered on GHC 9.0.1
   text-short = self.text-short_0_1_5;
 
-  # 2021-09-18: The following plugins don‘t work yet on ghc9.
-  haskell-language-server = appendConfigureFlags [
-    "-f-tactic"
-    "-f-splice"
-    "-f-refineimports"
-    "-f-class"
+  fourmolu = doJailbreak self.fourmolu_0_4_0_0;
 
-    "-f-fourmolu"
+  # 2022-02-05: The following plugins don‘t work yet on ghc9.
+  # Compare: https://haskell-language-server.readthedocs.io/en/latest/supported-versions.html
+  haskell-language-server = appendConfigureFlags [
     "-f-brittany"
     "-f-stylishhaskell"
   ] (super.haskell-language-server.override {
-    hls-tactics-plugin = null; # No upstream support, generic-lens-core fail
-    hls-splice-plugin = null; # No upstream support in hls 1.4.0, should be fixed in 1.5
-    hls-refine-imports-plugin = null; # same issue es splice-plugin
-    hls-class-plugin = null; # No upstream support
-
-    hls-fourmolu-plugin = null; # No upstream support, needs new fourmolu release
     hls-stylish-haskell-plugin = null; # No upstream support
     hls-brittany-plugin = null; # Dependencies don't build with 9.0.1
   });
diff --git a/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml b/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
index 799a668ea075..56a6cb41cbaf 100644
--- a/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
+++ b/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
@@ -167,6 +167,7 @@ extra-packages:
   - brick == 0.64.*                     # 2021-12-03: matterhorn depends on brick < 0.65
   - path == 0.9.0                       # 2021-12-03: path version building with stackage genvalidity and GHC 9.0.2
   - ormolu == 0.3.*                     # 2021-12-03: for HLS with GHC 9.0.2
+  - fourmolu == 0.4.*                   # 2022-02-05: for HLS with GHC 9.0.2
 
 package-maintainers:
   abbradar:
diff --git a/pkgs/development/haskell-modules/hackage-packages.nix b/pkgs/development/haskell-modules/hackage-packages.nix
index 1e5d7ff77b33..cb57b7404f8e 100644
--- a/pkgs/development/haskell-modules/hackage-packages.nix
+++ b/pkgs/development/haskell-modules/hackage-packages.nix
@@ -98739,6 +98739,40 @@ self: {
        license = lib.licenses.bsd3;
      }) {};
 
+  "fourmolu_0_4_0_0" = callPackage
+    ({ mkDerivation, aeson, ansi-terminal, base, bytestring, Cabal
+     , containers, Diff, directory, dlist, exceptions, filepath
+     , ghc-lib-parser, gitrev, hspec, hspec-discover, HsYAML
+     , HsYAML-aeson, mtl, optparse-applicative, path, path-io, syb
+     , temporary, text
+     }:
+     mkDerivation {
+       pname = "fourmolu";
+       version = "0.4.0.0";
+       sha256 = "1mq0h6nsl7ssfwh6zqhyja7w212vn8msmlm5iwwimca279hzwywb";
+       revision = "1";
+       editedCabalFile = "03bwhqj547brmgk191gy3k9xayi6fqqk2f5sbz3ail1bk7b73xnq";
+       isLibrary = true;
+       isExecutable = true;
+       libraryHaskellDepends = [
+         aeson ansi-terminal base bytestring Cabal containers Diff directory
+         dlist exceptions filepath ghc-lib-parser HsYAML HsYAML-aeson mtl
+         syb text
+       ];
+       executableHaskellDepends = [
+         base directory filepath ghc-lib-parser gitrev optparse-applicative
+         text
+       ];
+       testHaskellDepends = [
+         base containers directory filepath hspec path path-io temporary
+         text
+       ];
+       testToolDepends = [ hspec-discover ];
+       description = "A formatter for Haskell source code";
+       license = lib.licenses.bsd3;
+       hydraPlatforms = lib.platforms.none;
+     }) {};
+
   "fourmolu_0_5_0_1" = callPackage
     ({ mkDerivation, aeson, ansi-terminal, array, base, bytestring
      , Cabal, containers, Diff, directory, dlist, exceptions, filepath