Resolve haskell#6409: Add public multilib test(s)

Also add a test for current behaviour
of haskell#6083

And variant with mixin, for haskell#6281

The tests are disable for GHC older than 8.8
Should they work?

Makefile

@@ -197,4 +197,4 @@ weeder :
 # tags
 .PHONY : tags
 tags :
-	hasktags -b Cabal/Distribution Cabal/Cabal-described/src Cabal/Language cabal-install/Distribution
+	hasktags -b Cabal/Distribution Cabal/Cabal-described/src Cabal/Language cabal-install/Distribution cabal-testsuite/src

cabal-testsuite/PackageTests/MultipleLibraries/Successful/cabal.out

@@ -0,0 +1,14 @@
+# cabal v2-run
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - pkg-def-0.1.0.0 (lib:publib) (first run)
+ - pkg-abc-0.1.0.0 (exe:program) (first run)
+Warning: pkg-def.cabal:13:27: visibility is experimental feature (issue #5660)
+Configuring library 'publib' for pkg-def-0.1.0.0..
+Preprocessing library 'publib' for pkg-def-0.1.0.0..
+Building library 'publib' for pkg-def-0.1.0.0..
+Warning: pkg-abc.cabal:10:15: colon specifier is experimental feature (issue #5660)
+Configuring executable 'program' for pkg-abc-0.1.0.0..
+Preprocessing executable 'program' for pkg-abc-0.1.0.0..
+Building executable 'program' for pkg-abc-0.1.0.0..

cabal-testsuite/PackageTests/MultipleLibraries/Successful/cabal.project

@@ -0,0 +1,4 @@
+packages:
+  pkg-abc
+  pkg-def
+

cabal-testsuite/PackageTests/MultipleLibraries/Successful/cabal.test.hs

@@ -0,0 +1,7 @@
+import Test.Cabal.Prelude
+main = cabalTest $ do
+    -- https://github.com/haskell/cabal/pull/6047 should make this work for older GHCs too?
+    skipIf =<< ghcVersionIs (< mkVersion [8,8])
+
+    cabal' "v2-run" ["pkg-abc:program"] >>= assertOutputContains "pkg-def:publib"
+

cabal-testsuite/PackageTests/MultipleLibraries/Successful/pkg-abc/Main.hs

@@ -0,0 +1,5 @@
+module Main (main) where
+import PkgDef (defValue)
+
+main :: IO ()
+main = print defValue

cabal-testsuite/PackageTests/MultipleLibraries/Successful/pkg-abc/pkg-abc.cabal

@@ -0,0 +1,10 @@
+cabal-version: 3.0
+name:          pkg-abc
+version:       0.1.0.0
+
+executable program
+  default-language: Haskell2010
+  main-is:          Main.hs
+  build-depends:
+    , base
+    , pkg-def:publib

cabal-testsuite/PackageTests/MultipleLibraries/Successful/pkg-def/pkg-def.cabal

@@ -0,0 +1,17 @@
+cabal-version: 3.0
+name:          pkg-def
+version:       0.1.0.0
+
+library
+  default-language: Haskell2010
+  hs-source-dirs:   src
+  build-depends:    base
+  exposed-modules:  PkgDef
+
+library publib
+  default-language: Haskell2010
+  visibility:       public
+  hs-source-dirs:   publib
+  build-depends:    base
+  exposed-modules:  PkgDef
+

cabal-testsuite/PackageTests/MultipleLibraries/Successful/pkg-def/publib/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:publib"

cabal-testsuite/PackageTests/MultipleLibraries/Successful/pkg-def/src/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/cabal.out

@@ -0,0 +1,14 @@
+# cabal v2-run
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - pkg-abc-0.1.0.0 (lib:pkg-def) (first run)
+ - pkg-abc-0.1.0.0 (exe:program) (first run)
+Warning: pkg-abc.cabal:19:15: colon specifier is experimental feature (issue #5660)
+Configuring library 'pkg-def' for pkg-abc-0.1.0.0..
+Preprocessing library 'pkg-def' for pkg-abc-0.1.0.0..
+Building library 'pkg-def' for pkg-abc-0.1.0.0..
+Warning: pkg-abc.cabal:19:15: colon specifier is experimental feature (issue #5660)
+Configuring executable 'program' for pkg-abc-0.1.0.0..
+Preprocessing executable 'program' for pkg-abc-0.1.0.0..
+Building executable 'program' for pkg-abc-0.1.0.0..

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/cabal.project

@@ -0,0 +1,4 @@
+packages:
+  pkg-abc
+  pkg-def
+

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/cabal.test.hs

@@ -0,0 +1,9 @@
+import Test.Cabal.Prelude
+
+-- https://github.com/haskell/cabal/issues/6083
+-- see pkg-abc.cabal
+main = cabalTest $ do
+    -- https://github.com/haskell/cabal/pull/6047 should make this work for older GHCs too?
+    skipIf =<< ghcVersionIs (< mkVersion [8,8])
+
+    cabal' "v2-run" ["pkg-abc:program"] >>= assertOutputContains "pkg-abc:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/pkg-abc/exe/Main.hs

@@ -0,0 +1,5 @@
+module Main (main) where
+import PkgDef (defValue)
+
+main :: IO ()
+main = print defValue

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/pkg-abc/pkg-abc.cabal

@@ -0,0 +1,19 @@
+cabal-version: 3.0
+name:          pkg-abc
+version:       0.1.0.0
+
+library pkg-def
+  default-language: Haskell2010
+  hs-source-dirs:   pkg-def
+  build-depends:    base
+  exposed-modules:  PkgDef
+
+executable program
+  default-language: Haskell2010
+  hs-source-dirs:   exe
+  main-is:          Main.hs
+
+  -- we want that to resolve to pkg-def main library.
+  build-depends:
+    , base
+    , pkg-def:pkg-def

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/pkg-abc/pkg-def/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-abc:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/pkg-def/pkg-def.cabal

@@ -0,0 +1,17 @@
+cabal-version: 3.0
+name:          pkg-def
+version:       0.1.0.0
+
+library
+  default-language: Haskell2010
+  hs-source-dirs:   src
+  build-depends:    base
+  exposed-modules:  PkgDef
+
+library publib
+  default-language: Haskell2010
+  visibility:       public
+  hs-source-dirs:   publib
+  build-depends:    base
+  exposed-modules:  PkgDef
+

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/pkg-def/publib/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:publib"

cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/pkg-def/src/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/cabal.out

@@ -0,0 +1,14 @@
+# cabal v2-run
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - pkg-abc-0.1.0.0 (lib:pkg-def) (first run)
+ - pkg-abc-0.1.0.0 (exe:program) (first run)
+Warning: pkg-abc.cabal:20:15: colon specifier is experimental feature (issue #5660)
+Configuring library 'pkg-def' for pkg-abc-0.1.0.0..
+Preprocessing library 'pkg-def' for pkg-abc-0.1.0.0..
+Building library 'pkg-def' for pkg-abc-0.1.0.0..
+Warning: pkg-abc.cabal:20:15: colon specifier is experimental feature (issue #5660)
+Configuring executable 'program' for pkg-abc-0.1.0.0..
+Preprocessing executable 'program' for pkg-abc-0.1.0.0..
+Building executable 'program' for pkg-abc-0.1.0.0..

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/cabal.project

@@ -0,0 +1,4 @@
+packages:
+  pkg-abc
+  pkg-def
+

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/cabal.test.hs

@@ -0,0 +1,9 @@
+import Test.Cabal.Prelude
+
+-- This is like T6083Pre, but also goes via mixins
+--
+main = cabalTest $ do
+    -- https://github.com/haskell/cabal/pull/6047 should make this work for older GHCs too?
+    skipIf =<< ghcVersionIs (< mkVersion [8,8])
+
+    cabal' "v2-run" ["pkg-abc:program"] >>= assertOutputContains "pkg-abc:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/pkg-abc/exe/Main.hs

@@ -0,0 +1,5 @@
+module Main (main) where
+import Mixin (defValue)
+
+main :: IO ()
+main = print defValue

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/pkg-abc/pkg-abc.cabal

@@ -0,0 +1,20 @@
+cabal-version: 3.0
+name:          pkg-abc
+version:       0.1.0.0
+
+library pkg-def
+  default-language: Haskell2010
+  hs-source-dirs:   pkg-def
+  build-depends:    base
+  exposed-modules:  PkgDef
+
+executable program
+  default-language: Haskell2010
+  hs-source-dirs:   exe
+  main-is:          Main.hs
+  mixins:           pkg-def (PkgDef as Mixin)
+
+  -- we want that to resolve to pkg-def main library.
+  build-depends:
+    , base
+    , pkg-def:pkg-def

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/pkg-abc/pkg-def/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-abc:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/pkg-def/pkg-def.cabal

@@ -0,0 +1,17 @@
+cabal-version: 3.0
+name:          pkg-def
+version:       0.1.0.0
+
+library
+  default-language: Haskell2010
+  hs-source-dirs:   src
+  build-depends:    base
+  exposed-modules:  PkgDef
+
+library publib
+  default-language: Haskell2010
+  visibility:       public
+  hs-source-dirs:   publib
+  build-depends:    base
+  exposed-modules:  PkgDef
+

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/pkg-def/publib/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:publib"

cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/pkg-def/src/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:pkg-def"