From 2686e6d493067c50448374de15e20924da519994 Mon Sep 17 00:00:00 2001
From: Matthew Bauer <mjbauer95@gmail.com>
Date: Mon, 4 Feb 2019 15:33:31 -0500
Subject: [PATCH 1/3] Replace - with _ in package name

---
 third_party/cabal2bazel/bzl/cabal_paths.bzl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/third_party/cabal2bazel/bzl/cabal_paths.bzl b/third_party/cabal2bazel/bzl/cabal_paths.bzl
index d111f63..e41d62a 100644
--- a/third_party/cabal2bazel/bzl/cabal_paths.bzl
+++ b/third_party/cabal2bazel/bzl/cabal_paths.bzl
@@ -93,7 +93,7 @@ def cabal_paths(name=None, package=None, data_dir='',data=[], version=[], **kwar
     data: The data files that this package depends on to run.
     version: The version number of this package (list of ints)
   """
-  module_name = "Paths_" + package
+  module_name = "Paths_" + package.replace("-", "_")
   paths_file = module_name + ".hs"
   _path_module_gen(
       name = paths_file,

From 5f0d7da660e0dfeea8bcca7387d6fa43347099db Mon Sep 17 00:00:00 2001
From: Matthew Bauer <mjbauer95@gmail.com>
Date: Mon, 4 Feb 2019 15:37:11 -0500
Subject: [PATCH 2/3] =?UTF-8?q?Don=E2=80=99t=20use=20relativize=20paths=20?=
 =?UTF-8?q?in=20internal=20modules?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This makes it possible to use cabal_paths with local projects.

Fixes #75.
---
 third_party/cabal2bazel/bzl/cabal_paths.bzl | 30 ++++++++++++++-------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/third_party/cabal2bazel/bzl/cabal_paths.bzl b/third_party/cabal2bazel/bzl/cabal_paths.bzl
index e41d62a..f3f5bd4 100644
--- a/third_party/cabal2bazel/bzl/cabal_paths.bzl
+++ b/third_party/cabal2bazel/bzl/cabal_paths.bzl
@@ -31,19 +31,31 @@ def _impl_path_module_gen(ctx):
   base_dir = ctx.label.package + (
       ("/" + ctx.attr.data_dir) if ctx.attr.data_dir else "")
 
-  ctx.template_action(
+  # If workspace_root is not empty, we have an external repo.
+  # We need to relativize the paths.
+  if ctx.label.workspace_root != "":
+    ctx.template_action(
       template=ctx.file._template,
       output=paths_file,
       substitutions={
-          "%{module}": ctx.attr.module,
-          "%{base_dir}": paths.join(
-              # TODO: this probably won't work for packages not in external
-              # repositories.  See:
-              # https://github.com/bazelbuild/bazel/wiki/Updating-the-runfiles-tree-structure
-              "..", paths.relativize(ctx.label.workspace_root, "external"), base_dir),
-          "%{version}": str(ctx.attr.version),
+        "%{module}": ctx.attr.module,
+        "%{base_dir}": paths.join(
+          # https://github.com/bazelbuild/bazel/wiki/Updating-the-runfiles-tree-structure
+          "..", paths.relativize(ctx.label.workspace_root, "external"), base_dir),
+        "%{version}": str(ctx.attr.version),
       },
-  )
+    )
+  else: # Otherwise this is a local directory, and we can use relative paths.
+    ctx.template_action(
+      template=ctx.file._template,
+      output=paths_file,
+      substitutions={
+        "%{module}": ctx.attr.module,
+        "%{base_dir}": base_dir,
+        "%{version}": str(ctx.attr.version),
+      },
+    )
+
   return struct(files=depset([paths_file]))
 
 

From a213699336644722f4d009cc9b34a4a686cb2fdf Mon Sep 17 00:00:00 2001
From: Matthew Bauer <mjbauer95@gmail.com>
Date: Tue, 5 Feb 2019 11:54:48 -0500
Subject: [PATCH 3/3] Add test for cabal_paths

These are based off of the tests in google/cabal2bazel here:

https://github.com/google/cabal2bazel

The test just uses cabal_paths to build PathsTest.hs.
---
 test/BUILD        | 21 +++++++++++++++++++++
 test/PathsTest.hs | 23 +++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 test/PathsTest.hs

diff --git a/test/BUILD b/test/BUILD
index ec3c6dc..1bd5a99 100644
--- a/test/BUILD
+++ b/test/BUILD
@@ -33,3 +33,24 @@ haskell_doctest(
     name = "doctest-test",
     deps = [":DoctestExample"],
 )
+
+load("//:third_party/cabal2bazel/bzl/cabal_paths.bzl", "cabal_paths")
+
+cabal_paths(
+    name = "foo-paths",
+    package = "foo",
+    version = [
+        1,
+        2,
+    ],
+)
+
+haskell_test(
+    name = "PathsTest",
+    srcs = ["PathsTest.hs"],
+    deps = [
+        ":foo-paths",
+        hazel_library("base"),
+        hazel_library("filepath"),
+    ],
+)
diff --git a/test/PathsTest.hs b/test/PathsTest.hs
new file mode 100644
index 0000000..29cc1d4
--- /dev/null
+++ b/test/PathsTest.hs
@@ -0,0 +1,23 @@
+-- Copyright 2018 Google LLC
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--    https://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+module Main where
+
+import qualified Paths_foo
+
+import Data.Version (versionBranch)
+import Control.Exception (assert)
+
+main = do
+    assert (versionBranch Paths_foo.version == [1, 2]) $ return ()