fix the imports on the filter directory test (#782)

pkg/BUILD

@@ -105,4 +105,11 @@ py_binary(
     visibility = ["//visibility:public"],
 )
 
+py_library(
+    name = "filter_directory_lib",
+    srcs = ["filter_directory.py"],
+    srcs_version = "PY3",
+    visibility = ["//visibility:public"],
+)
+
 exports_files(["verify_archive_test_main.py.tpl"])

tests/mappings/filter_directory/BUILD

@@ -227,7 +227,9 @@ directory(
 py_test(
     name = "negative_tests",
     srcs = ["test_filter_directory.py"],
-    data = ["//pkg:filter_directory"],
     main = "test_filter_directory.py",
-    deps = ["@rules_python//python/runfiles"],
+    deps = [
+        "//pkg:filter_directory_lib",
+        "@rules_python//python/runfiles",
+    ],
 )

tests/mappings/filter_directory/test_filter_directory.py

@@ -24,21 +24,9 @@
 import tempfile
 import unittest
 
+from pkg import filter_directory
 from python.runfiles import runfiles
 
-# Get the filter_directory script into the import path.  There might be a
-# better way to do this, but it works.
-
-rf = runfiles.Create()
-filter_directory_script = rf.Rlocation('/'.join([
-    os.environ["TEST_WORKSPACE"],
-    "pkg",
-    "filter_directory"
-]))
-
-sys.path.append(os.path.dirname(filter_directory_script))
-import filter_directory  # noqa: E402
-
 
 # TODO: These tests are largely to ensure that filter_directory fails, but it
 # does not check _why_ they fail.