Add env_inherit to py_test

examples/pytest/BUILD.bazel

@@ -11,6 +11,7 @@ py_test(
         "foo_test.py",
         ":__test__",
     ],
+    env_inherit = ["FOO"],
     imports = ["../.."],
     main = ":__test__.py",
     package_collisions = "warning",

py/private/py_binary.bzl

@@ -126,6 +126,7 @@ def _py_binary_rule_impl(ctx):
         instrumented_files_info,
         RunEnvironmentInfo(
             environment = passed_env,
+            inherited_environment = getattr(ctx.attr, "env_inherit", []),
         ),
     ]
 
@@ -172,6 +173,13 @@ A collision can occour when multiple packages providing the same file are instal
 
 _attrs.update(**_py_library.attrs)
 
+_test_attrs = dict({
+    "env_inherit": attr.string_list(
+        doc = "Specifies additional environment variables to inherit from the external environment when the test is executed by bazel test.",
+        default = [],
+    ),
+})
+
 def _python_version_transition_impl(_, attr):
     if not attr.python_version:
         return {}
@@ -186,6 +194,7 @@ _python_version_transition = transition(
 py_base = struct(
     implementation = _py_binary_rule_impl,
     attrs = _attrs,
+    test_attrs = _test_attrs,
     toolchains = [
         PY_TOOLCHAIN,
         VENV_TOOLCHAIN,
@@ -205,7 +214,7 @@ py_binary = rule(
 py_test = rule(
     doc = "Run a Python program under Bazel. Most users should use the [py_test macro](#py_test) instead of loading this directly.",
     implementation = py_base.implementation,
-    attrs = py_base.attrs,
+    attrs = py_base.attrs | py_base.test_attrs,
     toolchains = py_base.toolchains,
     test = True,
     cfg = py_base.cfg,