Added stylish-haskell to github-actions

Author: coot

.github/workflows/haskell.yml

@@ -65,3 +65,32 @@ jobs:
     - name: io-sim [test]
       run: cabal run io-sim:test
 
+  stylish-haskell:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Set cache versioj
+      run: echo "CACHE_VERSION=hi5eTh3A" >> $GITHUB_ENV
+
+    - name: "Setup haskell"
+      uses: haskell/actions/setup@v1
+      id: setup-haskell
+      with:
+        ghc-version: 9.2.2
+        cabal-version: 3.6.2.0
+
+    - uses: actions/cache@v3
+      name: "Cache `cabal store`"
+      with:
+        path: ${{ steps.setup-haskell.outputs.cabal-store }}
+        key: cache-dependencies-${{ env.CACHE_VERSION }}-${{ hashFiles('dependencies.txt') }}
+        restore-keys: cache-dependencies-${{ env.CACHE_VERSION }}-${{ runner.os }}-${{ matrix.ghc }}
+
+    - name: "Install stylish-haskell"
+      run: |
+        cabal install stylish-haskell
+
+    - name: "Run stylish-haskell"
+      run: |
+        ./scripts/stylish-haskell.sh
+        git diff --exit-code