Add pre-commit hook for cleaning up mixed-line endings (#2679)

* Update pre-commit hook to include changing line endings

* Fix non-lf lines

* Check pre-commit excludes files

* Revert "Check pre-commit excludes files"

This reverts commit 7b9670f863.

* Actually add the exclude to contributing docs

* Fix merge failure with previous patch

* Inadvertently overwrote merge

* Add LF option for stylish-haskell and pre-commit file

Co-authored-by: Anton Latukha <anton.latukha@gmail.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

.gitignore

@@ -32,7 +32,7 @@ test/testdata/**/hie.yaml
 .shake/
 
 # pre-commit-hook.nix
-.pre-commit-config.yaml
+#.pre-commit-config.yaml
 
 # direnv
 /.direnv/

.pre-commit-config.yaml

@@ -0,0 +1,32 @@
+{
+  "repos": [
+    {
+      "hooks": [
+        {
+          "entry": "stylish-haskell --inplace",
+          "exclude": "(^Setup.hs$|test/testdata/.*$|test/data/.*$|test/manual/lhs/.*$|^hie-compat/.*$|^plugins/hls-tactics-plugin/.*$|^ghcide/src/Development/IDE/GHC/Compat.hs$|^ghcide/src/Development/IDE/Plugin/CodeAction/ExactPrint.hs$|^ghcide/src/Development/IDE/GHC/Compat/Core.hs$|^ghcide/src/Development/IDE/Spans/Pragmas.hs$|^ghcide/src/Development/IDE/LSP/Outline.hs$|^plugins/hls-splice-plugin/src/Ide/Plugin/Splice.hs$|^ghcide/test/exe/Main.hs$|ghcide/src/Development/IDE/Core/Rules.hs|^hls-test-utils/src/Test/Hls/Util.hs$)",
+          "files": "\\.l?hs$",
+          "id": "stylish-haskell",
+          "language": "system",
+          "name": "stylish-haskell",
+          "pass_filenames": true,
+          "types": [
+            "file"
+          ]
+        }
+      ],
+      "repo": "local"
+    },
+    {
+       "repo": "https://github.com/pre-commit/pre-commit-hooks",
+       "rev": "v4.1.0",
+       "hooks": [
+          {
+            "id": "mixed-line-ending",
+            "args": ["--fix", "lf"],
+            "exclude": "test/testdata/.*CRLF*.hs$"
+          }
+       ]
+    }
+  ]
+}

.stylish-haskell.yaml

@@ -53,7 +53,7 @@ steps:
 
 columns: 80
 
-newline: native
+newline: lf
 
 language_extensions:
   - BangPatterns

docs/contributing/contributing.md

@@ -199,6 +199,17 @@ If you don't want to use [nix](https://nixos.org/guides/install-nix.html), you c
         }
       ],
       "repo": "local"
+    },
+    {
+       "repo": "https://github.com/pre-commit/pre-commit-hooks",
+       "rev": "v4.1.0",
+       "hooks": [
+          {
+            "id": "mixed-line-ending",
+            "args": ["--fix", "lf"],
+            "exclude": "test/testdata/.*CRLF*.hs$"
+          }
+       ]
     }
   ]
 }

plugins/hls-retrie-plugin/src/Ide/Plugin/Retrie.hs

@@ -32,9 +32,9 @@ import           Data.Aeson                           (FromJSON (..),
                                                        Value (Null),
                                                        genericParseJSON)
 import qualified Data.Aeson                           as Aeson
-import qualified Data.ByteString                      as BS
 import           Data.Bifunctor                       (Bifunctor (first),
                                                        second)
+import qualified Data.ByteString                      as BS
 import           Data.Coerce
 import           Data.Either                          (partitionEithers)
 import qualified Data.HashMap.Strict                  as HM