feat(third_party/bazel): Check in rules_haskell from Tweag

third_party/bazel/rules_haskell/tests/library-exports/BUILD.bazel

@@ -0,0 +1,41 @@
+load(
+    "@io_tweag_rules_haskell//haskell:haskell.bzl",
+    "haskell_library",
+    "haskell_test",
+)
+
+package(default_testonly = 1)
+
+haskell_library(
+    name = "sublib",
+    srcs = ["TestSubLib.hs"],
+    exports = {"//tests/hackage:containers": "Data.Map as SubLib.Map"},
+    deps = [
+        "//tests/hackage:base",
+        "//tests/hackage:containers",
+    ],
+)
+
+haskell_library(
+    name = "lib",
+    srcs = ["TestLib.hs"],
+    exports = {
+        ":sublib": "TestSubLib",
+        "//tests/hackage:containers": "Data.Map as Lib.Map",
+    },
+    deps = [
+        ":sublib",
+        "//tests/hackage:base",
+    ],
+)
+
+haskell_test(
+    name = "library-exports",
+    size = "small",
+    srcs = ["Bin.hs"],
+    visibility = ["//visibility:public"],
+    deps = [
+        ":lib",
+        "//tests/hackage:base",
+    ],
+)

third_party/bazel/rules_haskell/tests/library-exports/Bin.hs

@@ -0,0 +1,7 @@
+module Main (main) where
+
+import TestSubLib (messageEnd)
+import Lib.Map
+
+main :: IO ()
+main = print $ Lib.Map.singleton 1 messageEnd

third_party/bazel/rules_haskell/tests/library-exports/TestLib.hs

@@ -0,0 +1,7 @@
+module TestLib (testMessage) where
+
+import TestSubLib (messageEnd)
+import SubLib.Map
+
+testMessage :: String
+testMessage = "hello " ++ messageEnd

third_party/bazel/rules_haskell/tests/library-exports/TestSubLib.hs

@@ -0,0 +1,5 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+module TestSubLib (messageEnd) where
+
+messageEnd :: String
+messageEnd = "world"