Add check tests for default-language (#6288)

Cabal/Cabal.cabal

@@ -189,6 +189,18 @@ extra-source-files:
   tests/ParserTests/regressions/issue-6083-pkg-pkg.cabal
   tests/ParserTests/regressions/issue-6083-pkg-pkg.expr
   tests/ParserTests/regressions/issue-6083-pkg-pkg.format
+  tests/ParserTests/regressions/issue-6288-a.cabal
+  tests/ParserTests/regressions/issue-6288-a.check
+  tests/ParserTests/regressions/issue-6288-b.cabal
+  tests/ParserTests/regressions/issue-6288-b.check
+  tests/ParserTests/regressions/issue-6288-c.cabal
+  tests/ParserTests/regressions/issue-6288-c.check
+  tests/ParserTests/regressions/issue-6288-d.cabal
+  tests/ParserTests/regressions/issue-6288-d.check
+  tests/ParserTests/regressions/issue-6288-e.cabal
+  tests/ParserTests/regressions/issue-6288-e.check
+  tests/ParserTests/regressions/issue-6288-f.cabal
+  tests/ParserTests/regressions/issue-6288-f.check
   tests/ParserTests/regressions/issue-774.cabal
   tests/ParserTests/regressions/issue-774.check
   tests/ParserTests/regressions/issue-774.expr

Cabal/Distribution/FieldGrammar/Newtypes.hs

@@ -158,6 +158,10 @@ instance (Newtype a b, Ord a, Sep sep, Parsec b) => Parsec (Set' sep b a) where
 instance (Newtype a b, Sep sep, Pretty b) => Pretty (Set' sep b a) where
     pretty = prettySep (Proxy :: Proxy sep) . map (pretty . (pack :: a -> b)) . Set.toList . unpack
 
+-------------------------------------------------------------------------------
+-- Identifiers
+-------------------------------------------------------------------------------
+
 -- | Haskell string or @[^ ,]+@
 newtype Token = Token { getToken :: String }
 
@@ -191,6 +195,21 @@ instance Parsec a => Parsec (MQuoted a) where
 instance Pretty a => Pretty (MQuoted a)  where
     pretty = pretty . unpack
 
+-- | Filepath are parsed as 'Token'.
+newtype FilePathNT = FilePathNT { getFilePathNT :: String }
+
+instance Newtype String FilePathNT
+
+instance Parsec FilePathNT where
+    parsec = pack <$> parsecToken
+
+instance Pretty FilePathNT where
+    pretty = showFilePath . unpack
+
+-------------------------------------------------------------------------------
+-- SpecVersion
+-------------------------------------------------------------------------------
+
 -- | Version range or just version, i.e. @cabal-version@ field.
 --
 -- There are few things to consider:
@@ -278,6 +297,10 @@ instance Pretty SpecVersion where
         | csv >= CabalSpecV1_12 = text (showCabalSpecVersion csv)
         | otherwise             = text ">=" <<>> text (showCabalSpecVersion csv)
 
+-------------------------------------------------------------------------------
+-- SpecLicense
+-------------------------------------------------------------------------------
+
 -- | SPDX License expression or legacy license
 newtype SpecLicense = SpecLicense { getSpecLicense :: Either SPDX.License License }
 
@@ -293,6 +316,10 @@ instance Parsec SpecLicense where
 instance Pretty SpecLicense where
     pretty = either pretty pretty . unpack
 
+-------------------------------------------------------------------------------
+-- TestedWith
+-------------------------------------------------------------------------------
+
 -- | Version range or just version
 newtype TestedWith = TestedWith { getTestedWith :: (CompilerFlavor, VersionRange) }
 
@@ -305,21 +332,6 @@ instance Pretty TestedWith where
     pretty x = case unpack x of
         (compiler, vr) -> pretty compiler <+> pretty vr
 
--- | Filepath are parsed as 'Token'.
-newtype FilePathNT = FilePathNT { getFilePathNT :: String }
-
-instance Newtype String FilePathNT
-
-instance Parsec FilePathNT where
-    parsec = pack <$> parsecToken
-
-instance Pretty FilePathNT where
-    pretty = showFilePath . unpack
-
--------------------------------------------------------------------------------
--- Internal
--------------------------------------------------------------------------------
-
 parsecTestedWith :: CabalParsing m => m (CompilerFlavor, VersionRange)
 parsecTestedWith = do
     name <- lexemeParsec

Cabal/tests/CheckTests.hs

@@ -42,6 +42,12 @@ checkTests = testGroup "regressions"
     , checkTest "assoc-cpp-options.cabal"
     , checkTest "public-multilib-1.cabal"
     , checkTest "public-multilib-2.cabal"
+    , checkTest "issue-6288-a.cabal"
+    , checkTest "issue-6288-b.cabal"
+    , checkTest "issue-6288-c.cabal"
+    , checkTest "issue-6288-d.cabal"
+    , checkTest "issue-6288-e.cabal"
+    , checkTest "issue-6288-f.cabal"
     ]
 
 checkTest :: FilePath -> TestTree

Cabal/tests/ParserTests/regressions/issue-6288-a.cabal

@@ -0,0 +1,14 @@
+cabal-version: >=1.8
+name:          issue
+version:       6288
+build-type:    Simple
+synopsis:      default-language optionality
+category:      Test
+description:   Field is introduced in 1.10, defaulted in 3.4
+license:       BSD3
+license-file:  LICENSE
+maintainer:    Cabal Contributors
+
+library
+  default-language: Haskell2010
+  exposed-modules:  Foo

Cabal/tests/ParserTests/regressions/issue-6288-a.check

@@ -0,0 +1 @@
+To use the 'default-language' field the package needs to specify at least 'cabal-version: >= 1.10'.

Cabal/tests/ParserTests/regressions/issue-6288-b.cabal

@@ -0,0 +1,13 @@
+cabal-version: >= 1.8
+name:          issue
+version:       6288
+build-type:    Simple
+synopsis:      default-language optionality
+category:      Test
+description:   Field is introduced in 1.10, defaulted in 3.4
+license:       BSD3
+license-file:  LICENSE
+maintainer:    Cabal Contributors
+
+library
+  exposed-modules:  Foo

Cabal/tests/ParserTests/regressions/issue-6288-c.cabal

@@ -0,0 +1,14 @@
+cabal-version: >= 1.10
+name:          issue
+version:       6288
+build-type:    Simple
+synopsis:      default-language optionality
+category:      Test
+description:   Field is introduced in 1.10, defaulted in 3.4
+license:       BSD3
+license-file:  LICENSE
+maintainer:    Cabal Contributors
+
+library
+  default-language: Haskell2010
+  exposed-modules:  Foo

Cabal/tests/ParserTests/regressions/issue-6288-d.cabal

@@ -0,0 +1,13 @@
+cabal-version: >=1.10
+name:          issue
+version:       6288
+build-type:    Simple
+synopsis:      default-language optionality
+category:      Test
+description:   Field is introduced in 1.10, defaulted in 3.4
+license:       BSD3
+license-file:  LICENSE
+maintainer:    Cabal Contributors
+
+library
+  exposed-modules:  Foo

Cabal/tests/ParserTests/regressions/issue-6288-d.check

@@ -0,0 +1 @@
+Packages using 'cabal-version: >= 1.10' must specify the 'default-language' field for each component (e.g. Haskell98 or Haskell2010). If a component uses different languages in different modules then list the other ones in the 'other-languages' field.

Cabal/tests/ParserTests/regressions/issue-6288-e.cabal

@@ -0,0 +1,13 @@
+cabal-version: 3.4
+name:          issue
+version:       6288
+synopsis:      default-language optionality
+category:      Test
+description:   Field is introduced in 1.10, defaulted in 3.4
+license:       BSD-3-Clause
+license-file:  LICENSE
+maintainer:    Cabal Contributors
+
+library
+  default-language: Haskell2010
+  exposed-modules:  Foo

Cabal/tests/ParserTests/regressions/issue-6288-f.cabal

@@ -0,0 +1,13 @@
+cabal-version: 3.4
+name:          issue
+version:       6288
+build-type:    Simple
+synopsis:      default-language optionality
+category:      Test
+description:   Field is introduced in 1.10, defaulted in 3.4
+license:       BSD-3-Clause
+license-file:  LICENSE
+maintainer:    Cabal Contributors
+
+library
+  exposed-modules:  Foo

Cabal/tests/ParserTests/regressions/issue-6288-f.check

@@ -0,0 +1 @@
+Packages using 'cabal-version: >= 1.10' must specify the 'default-language' field for each component (e.g. Haskell98 or Haskell2010). If a component uses different languages in different modules then list the other ones in the 'other-languages' field.