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

third_party/bazel/rules_haskell/tests/two-libs/BUILD.bazel

@@ -0,0 +1,42 @@
+load(
+    "@io_tweag_rules_haskell//haskell:haskell.bzl",
+    "haskell_library",
+    "haskell_test",
+)
+
+package(
+    default_testonly = 1,
+    default_visibility = ["//visibility:public"],
+)
+
+haskell_library(
+    name = "one",
+    srcs = ["One.hs"],
+    deps = [
+        "//tests/hackage:base",
+    ],
+)
+
+haskell_library(
+    name = "two",
+    srcs = ["Two.hs"],
+    deps = [
+        ":one",
+        "//tests/hackage:base",
+    ],
+)
+
+haskell_test(
+    name = "two-libs",
+    srcs = ["Main.hs"],
+    coverage_report_format = "html",
+    expected_covered_expressions_percentage = 55,
+    expected_uncovered_expression_count = 4,
+    experimental_coverage_source_patterns = [":two"],
+    strict_coverage_analysis = True,
+    tags = ["coverage-compatible"],
+    deps = [
+        ":two",
+        "//tests/hackage:base",
+    ],
+)

third_party/bazel/rules_haskell/tests/two-libs/Main.hs

@@ -0,0 +1,6 @@
+module Main where
+
+import Two (two)
+
+main :: IO ()
+main = putStrLn ("Two: " ++ show two)

third_party/bazel/rules_haskell/tests/two-libs/One.hs

@@ -0,0 +1,4 @@
+module One (one) where
+
+one :: Int
+one = 1

third_party/bazel/rules_haskell/tests/two-libs/Two.hs

@@ -0,0 +1,14 @@
+module Two (two) where
+
+import One (one)
+
+two :: Int
+two = 
+    if True then
+        one + one
+    else 
+        if True then
+            1
+        else
+            2
+