Add test that ensures we can correctly locate and open a data file.

Author: jsing-canva

tests/runfiles/BUILD.bazel

@@ -5,6 +5,9 @@ load("@rules_python//python/private:bzlmod_enabled.bzl", "BZLMOD_ENABLED")  # bu
 py_test(
     name = "runfiles_test",
     srcs = ["runfiles_test.py"],
+    data = [
+        "//tests/support:current_build_settings",
+    ],
     env = {
         "BZLMOD_ENABLED": "1" if BZLMOD_ENABLED else "0",
     },

tests/runfiles/runfiles_test.py

@@ -12,7 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import os
+import pathlib
 import tempfile
 import unittest
 from typing import Any, List, Optional
@@ -63,6 +65,14 @@ def testRlocationArgumentValidation(self) -> None:
             lambda: r.Rlocation("\\foo"),
         )
 
+    def testRlocationWithData(self) -> None:
+        rf = runfiles.Create()
+        settings_path = rf.Rlocation(
+            "rules_python/tests/support/current_build_settings.json"
+        )
+        settings = json.loads(pathlib.Path(settings_path).read_text())
+        self.assertIn("bootstrap_impl", settings)
+
     def testCreatesManifestBasedRunfiles(self) -> None:
         with _MockFile(contents=["a/b c/d"]) as mf:
             r = runfiles.Create(