Add fourmolu and update hook

.github/workflows/check-stylish-haskell.yml → .github/workflows/check-fourmolu.yml

@@ -1,4 +1,4 @@
-name: Check Stylish Haskell
+name: Check Fourmolu 
 
 on:
   merge_group:
@@ -19,64 +19,55 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  check-stylish-haskell:
+  check-fourmolu:
     runs-on: ubuntu-latest
 
-    strategy:
-      fail-fast: false
-
     env:
-      # Modify this value to "invalidate" the cabal cache.
-      CABAL_CACHE_VERSION: "2023-07-12"
-
-      STYLISH_HASKELL_VERSION: "0.14.4.0"
-
-      STYLISH_HASKELL_PATHS: >
-        cardano-api
+      FOURMOLU_VERSION: "0.16.2.0"
 
     steps:
-    - name: Download stylish-haskell
+    - name: Download Fourmolu
       run: |
-        version="${{ env.STYLISH_HASKELL_VERSION }}"
-
+        fourmolu_path="$(mktemp -d)"
+        version="${{env.FOURMOLU_VERSION}}"
         curl -sL \
-          "https://github.com/haskell/stylish-haskell/releases/download/v$version/stylish-haskell-v$version-linux-x86_64.tar.gz" \
-          | tar -C "/tmp" -xz
-
-        echo "PATH=/tmp/stylish-haskell-v$version-linux-x86_64:$PATH" >> "$GITHUB_ENV"
+          "https://github.com/fourmolu/fourmolu/releases/download/v$version/fourmolu-$version-linux-x86_64" > "$fourmolu_path/fourmolu"
+        echo "PATH=$fourmolu_path:$PATH" >> "$GITHUB_ENV"
+        chmod u+rwx "$fourmolu_path/fourmolu"
 
     - uses: actions/checkout@v3
 
-    - name: Run stylish-haskell over all Haskell files (always succeeds)
+    - name: Run Fourmolu over all Haskell files (always succeeds)
       run: |
         git add .
         git stash
 
-        for x in $(git ls-tree --full-tree --name-only -r HEAD ${{ env.STYLISH_HASKELL_PATHS }}); do
+        for x in $(git ls-tree --full-tree --name-only -r HEAD); do
           if [ "${x##*.}" == "hs" ]; then
             if grep -qE '^#' "$x"; then
               echo "$x contains CPP.  Skipping."
             else
-              stylish-haskell -i "$x"
+              fourmolu -q -i "$x"
             fi
           fi
         done
 
         git --no-pager diff
 
-    - name: Run stylish-haskell over all modified files
+    - name: Run Fourmolu over all modified files
       run: |
         git add .
         git stash
         git fetch origin ${{ github.base_ref }} --unshallow
-        for x in $(git diff --name-only --diff-filter=ACMR origin/${{ github.base_ref }}..HEAD ${{ env.STYLISH_HASKELL_PATHS }}); do
+        for x in $(git diff --name-only --diff-filter=ACMR origin/${{ github.base_ref }}..HEAD); do
           if [ "${x##*.}" == "hs" ]; then
             if grep -qE '^#' "$x"; then
               echo "$x contains CPP.  Skipping."
             else
-              stylish-haskell -i "$x"
+              fourmolu -q -i "$x"
             fi
           fi
         done
 
         git --no-pager diff --exit-code
+

flake.nix

@@ -112,6 +112,7 @@
               haskell-language-server.src = nixpkgs.haskell-nix.sources."hls-2.6";
               hlint = "3.6.1";
               stylish-haskell = "0.14.5.0";
+              fourmolu = "0.16.2.0";
             };
           # and from nixpkgs or other inputs
           shell.nativeBuildInputs = with nixpkgs; [gh jq yq-go actionlint shellcheck cabal-head];

fourmolu.yaml

@@ -0,0 +1,17 @@
+indentation: 2
+column-limit: 100
+function-arrows: leading
+comma-style: leading
+import-export-style: leading
+indent-wheres: true
+record-brace-space: true
+newlines-between-decls: 1
+haddock-style: single-line
+haddock-style-module:
+let-style: auto
+indent-wheres: false
+in-style: right-align
+unicode: never
+respectful: false
+fixities: []
+single-constraint-parens: never

scripts/githooks/haskell-style-lint

@@ -1,5 +1,5 @@
 #!/bin/sh
-# This script validates the staged changes in Haskell files using stylish-haskell and hlint and returns non-zero
+# This script validates the staged changes in Haskell files using fourmolu and hlint and returns non-zero
 # code when there are linting or style issues.
 #
 # To set this script as your pre-commit hook, use the following command:
@@ -13,7 +13,7 @@ for x in $(git diff --staged --name-only --diff-filter=ACM "*.hs" | tr '\n' ' ')
   if grep -qE '^#' "$x"; then
     echo "$x contains CPP.  Skipping."
   else
-    stylish-haskell -i "$x"
+    fourmolu -q -i "$x"
   fi
   hlint "$x" || hlint_rc="1"
 done