Fix #8316: run fix-whitespace --check as CI workflow

.github/workflows/whitespace.yml

@@ -0,0 +1,47 @@
+name: Whitespace
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+  release:
+    types:
+      - created
+jobs:
+  check:
+    runs-on: ubuntu-latest
+
+    env:
+     fix-whitespace-ver: '0.0.8'
+
+    steps:
+    - uses: actions/checkout@v3
+      name: Checkout sources
+
+    - name: Create directory for binary
+      run: |
+        mkdir -p $HOME/.local/bin
+
+    - uses: actions/cache@v3
+      name: Cache the binary
+      id: cache
+      with:
+        path: "~/.local/bin"
+        key: fix-whitespace-${{ env.fix-whitespace-ver }}
+
+    - uses: haskell/actions/setup@v1
+      if: ${{ !steps.cache.outputs.cache-hit }}
+      with:
+        ghc-version: '9.2'
+        cabal-version: latest
+
+    - name: Install fix-whitespace
+      if: ${{ !steps.cache.outputs.cache-hit }}
+      run: |
+        cabal install --ignore-project --install-method=copy --installdir=$HOME/.local/bin fix-whitespace-${{ env.fix-whitespace-ver }}
+        strip $HOME/.local/bin/fix-whitespace
+
+    - name: Check the whitespace issue
+      run: |
+        $HOME/.local/bin/fix-whitespace --check

.gitlab/ci.sh

@@ -8,15 +8,15 @@ export GHCUP_INSTALL_BASE_PREFIX="$CI_PROJECT_DIR/toolchain"
 export CABAL_DIR="$CI_PROJECT_DIR/cabal"
 
 case "$(uname)" in
-	MSYS_*|MINGW*)
-		export CABAL_DIR="$(cygpath -w "$CABAL_DIR")"
-		GHCUP_BINDIR="${GHCUP_INSTALL_BASE_PREFIX}/ghcup/bin"
-		EXE_EXT=".exe"
-		;;
-	*)
-		GHCUP_BINDIR="${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin"
-		EXE_EXT=""
-		;;
+    MSYS_*|MINGW*)
+        export CABAL_DIR="$(cygpath -w "$CABAL_DIR")"
+        GHCUP_BINDIR="${GHCUP_INSTALL_BASE_PREFIX}/ghcup/bin"
+        EXE_EXT=".exe"
+        ;;
+    *)
+        GHCUP_BINDIR="${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin"
+        EXE_EXT=""
+        ;;
 esac
 
 mkdir -p "$CABAL_DIR"
@@ -32,19 +32,19 @@ export BOOTSTRAP_HASKELL_ADJUST_CABAL_CONFIG=yes
 # for some reason the subshell doesn't pick up the arm64 environment on darwin
 # and starts installing x86_64 GHC
 case "$(uname -s)" in
-	"Darwin"|"darwin")
-		case "$(/usr/bin/arch)" in
-			aarch64|arm64|armv8l)
-				curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | arch -arm64 /bin/bash
-				;;
-			*)
-				curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
-				;;
-		esac
-		;;
-	*)
-		curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
-		;;
+    "Darwin"|"darwin")
+        case "$(/usr/bin/arch)" in
+            aarch64|arm64|armv8l)
+                curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | arch -arm64 /bin/bash
+                ;;
+            *)
+                curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
+                ;;
+        esac
+        ;;
+    *)
+        curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
+        ;;
 esac
 
 # https://github.com/haskell/cabal/issues/7313#issuecomment-811851884

CONTRIBUTING.md

@@ -113,10 +113,34 @@ names. When running `cabal-install` test suites, one need only use `cabal test`
 `cabal run <test-target>` in order to test locally.
 
 
-Conventions
------------
+Whitespace Conventions
+----------------------
 
-* Spaces, not tabs.
+* No tab characters allowed.
+* No trailing whitespace allowed.
+* File needs to be terminated by a newline character.
+
+These conventions are enforced by the
+[fix-whitespace](https://hackage.haskell.org/package/fix-whitespace)
+tool.  Install it from hackage as usual (`cabal install fix-whitespace`)
+and run it in the project root to fix whitespace violations.
+
+The files included in the automatic whitespace check are specified in
+`fix-whitespace.yaml`.  Please add to this file if you add textfiles
+to this repository that are not included by the rules given there.
+Note that files that make essential use of tab characters (like `Makefile`)
+should _not_ be included in the automatic check.
+
+Whitespace conventions are enforced by
+[CI](https://github.com/haskell/cabal/actions/workflows/whitespace.yml).
+If you push a fix of a whitespace violation, please do so in a
+_separate commit_.
+
+
+
+
+Other Conventions
+-----------------
 
 * Try to follow style conventions of a file you are modifying, and
   avoid gratuitous reformatting (it makes merges harder!)

Cabal-syntax/src/Distribution/Backpack.hs

@@ -98,7 +98,7 @@ data OpenUnitId
 -- TODO: cache holes?
 
 instance Binary OpenUnitId
-instance Structured OpenUnitId 
+instance Structured OpenUnitId
 instance NFData OpenUnitId where
     rnf (IndefFullUnitId cid subst) = rnf cid `seq` rnf subst
     rnf (DefiniteUnitId uid) = rnf uid

Cabal-syntax/src/Distribution/Fields/Pretty.hs

@@ -34,7 +34,7 @@ import qualified Distribution.Fields.Parser as P
 import qualified Data.ByteString  as BS
 import qualified Text.PrettyPrint as PP
 
--- | This type is used to discern when a comment block should go 
+-- | This type is used to discern when a comment block should go
 --   before or after a cabal-like file field, otherwise it would
 --   be hardcoded to a single position. It is often used in
 --   conjunction with @PrettyField@.
@@ -153,7 +153,7 @@ renderField (Opts rann indent post) fw (PrettyField ann name doc) =
     narrowStyle = PP.style { PP.lineLength = PP.lineLength PP.style - fw }
 
 renderField opts@(Opts rann indent post) _ (PrettySection ann name args fields) = Block Margin Margin $
-    
+
     attachComments
       (post ann [ PP.render $ PP.hsep $ PP.text (fromUTF8BS name) : args ])
     ++

Cabal-syntax/src/Distribution/SPDX/LicenseExceptionId.hs

@@ -29,7 +29,7 @@ import qualified Text.PrettyPrint as Disp
 -- LicenseExceptionId
 -------------------------------------------------------------------------------
 
--- | SPDX License Exceptions identifiers list v3.16 
+-- | SPDX License Exceptions identifiers list v3.16
 data LicenseExceptionId
     = DS389_exception -- ^ @389-exception@, 389 Directory Server Exception
     | Autoconf_exception_2_0 -- ^ @Autoconf-exception-2.0@, Autoconf exception 2.0

Cabal-syntax/src/Distribution/SPDX/LicenseId.hs

@@ -32,7 +32,7 @@ import qualified Text.PrettyPrint as Disp
 -- LicenseId
 -------------------------------------------------------------------------------
 
--- | SPDX License identifiers list v3.16 
+-- | SPDX License identifiers list v3.16
 data LicenseId
     = NullBSD -- ^ @0BSD@, BSD Zero Clause License
     | AAL -- ^ @AAL@, Attribution Assurance License

Cabal-syntax/src/Distribution/Types/CondTree.hs

@@ -198,4 +198,4 @@ foldCondTree e u mergeInclusive mergeExclusive = goTree
     goTree :: CondTree v c a -> b
     goTree (CondNode a c ifs) = u (c, a) `mergeInclusive` foldl goBranch e ifs
     goBranch :: b -> CondBranch v c a -> b
-    goBranch acc (CondBranch _ t mt) = mergeInclusive acc (maybe (goTree t) (mergeExclusive (goTree t) . goTree) mt)
+    goBranch acc (CondBranch _ t mt) = mergeInclusive acc (maybe (goTree t) (mergeExclusive (goTree t) . goTree) mt)

Cabal-syntax/src/Distribution/Types/ExeDependency.hs

@@ -37,7 +37,7 @@ instance Pretty ExeDependency where
       pver | isAnyVersion ver = PP.empty
            | otherwise        = pretty ver
 
--- | 
+-- |
 --
 -- Examples
 --

Cabal-syntax/src/Distribution/Types/LibraryName.hs

@@ -35,7 +35,7 @@ instance NFData LibraryName where rnf = genericRnf
 --
 -- /Note:/ there are no 'Pretty' or 'Parsec' instances,
 -- as there's other way to represent 'LibraryName', namely as bare
--- 'UnqualComponentName'. 
+-- 'UnqualComponentName'.
 prettyLibraryNameComponent :: LibraryName -> Disp.Doc
 prettyLibraryNameComponent LMainLibName      = Disp.text "lib"
 prettyLibraryNameComponent (LSubLibName str) = Disp.text "lib:" <<>> pretty str

Cabal-syntax/src/Distribution/Types/Mixin.hs

@@ -78,7 +78,7 @@ versionGuardMultilibs = do
     ]
 
 -- | Smart constructor of 'Mixin', enforces invariant.
--- 
+--
 -- @since 3.4.0.0
 mkMixin :: PackageName -> LibraryName -> IncludeRenaming -> Mixin
 mkMixin pn (LSubLibName uqn) incl

Cabal-syntax/src/Distribution/Types/PkgconfigVersion.hs

@@ -116,4 +116,3 @@ isDigit8 w = 0x30 <= w && w <= 0x39
 isAlpha8 :: Word8 -> Bool
 isAlpha8 w = (0x41 <= w && w <= 0x5A) || (0x61 <= w && w <= 0x7A)
 
-

Cabal-syntax/src/Distribution/Utils/Generic.hs

@@ -237,7 +237,7 @@ validateUTF8 = go 0 where
         Just (cn, bs') | cn .&. 0xC0 == 0x80 ->
             moreBytes (off + 1) (byteCount-1) overlong bs' ((acc `shiftL` 6) .|. fromIntegral cn .&. 0x3F)
         _ -> Just off
-        
+
 
 -- | Ignore a Unicode byte order mark (BOM) at the beginning of the input
 --

Cabal-tests/tests/ParserTests/errors/leading-comma-2c.cabal

@@ -8,7 +8,7 @@ library
   default-language: Haskell2010
   exposed-modules:
     LeadingComma, MixedComma NoComma
-   
+
 
   build-depends: base, containers
 

Cabal-tests/tests/ParserTests/regressions/cc-options-with-optimization.cabal

@@ -6,7 +6,7 @@ maintainer:    [email protected]
 name:          cxx-options-with-optimization
 synopsis:      test a build check
 version:       1
-         
+
 library
     build-depends: base >= 4.9 && <4.10
     cc-options: -O2

Cabal-tests/tests/ParserTests/regressions/cxx-options-with-optimization.cabal

@@ -6,7 +6,7 @@ maintainer:    [email protected]
 name:          cxx-options-with-optimization
 synopsis:      test a build check
 version:       1
-         
+
 library
     build-depends: base >= 4.9 && <4.10
     cxx-options: -O2