Refactor a test to not use the "working_env" fixture (#41308)

Co-authored-by: Harmen Stoppels <me@harmenstoppels.nl>

lib/spack/spack/test/conftest.py

@@ -713,9 +713,6 @@ def configuration_dir(tmpdir_factory, linux_os):
     t.write(content)
     yield tmpdir
 
-    # Once done, cleanup the directory
-    shutil.rmtree(str(tmpdir))
-
 
 def _create_mock_configuration_scopes(configuration_dir):
     """Create the configuration scopes used in `config` and `mutable_config`."""

lib/spack/spack/test/module_parsing.py

@@ -27,16 +27,13 @@
 ]
 
 
-def test_module_function_change_env(tmpdir, working_env):
-    src_file = str(tmpdir.join("src_me"))
-    with open(src_file, "w") as f:
-        f.write("export TEST_MODULE_ENV_VAR=TEST_SUCCESS\n")
-
-    os.environ["NOT_AFFECTED"] = "NOT_AFFECTED"
-    module("load", src_file, module_template=". {0} 2>&1".format(src_file))
-
-    assert os.environ["TEST_MODULE_ENV_VAR"] == "TEST_SUCCESS"
-    assert os.environ["NOT_AFFECTED"] == "NOT_AFFECTED"
+def test_module_function_change_env(tmp_path):
+    environb = {b"TEST_MODULE_ENV_VAR": b"TEST_FAIL", b"NOT_AFFECTED": b"NOT_AFFECTED"}
+    src_file = tmp_path / "src_me"
+    src_file.write_text("export TEST_MODULE_ENV_VAR=TEST_SUCCESS\n")
+    module("load", str(src_file), module_template=f". {src_file} 2>&1", environb=environb)
+    assert environb[b"TEST_MODULE_ENV_VAR"] == b"TEST_SUCCESS"
+    assert environb[b"NOT_AFFECTED"] == b"NOT_AFFECTED"
 
 
 def test_module_function_no_change(tmpdir):

lib/spack/spack/util/module_cmd.py

@@ -10,6 +10,7 @@
 import os
 import re
 import subprocess
+from typing import MutableMapping, Optional
 
 import llnl.util.tty as tty
 
@@ -21,8 +22,13 @@
 awk_cmd = r"""awk 'BEGIN{for(name in ENVIRON)""" r"""printf("%s=%s%c", name, ENVIRON[name], 0)}'"""
 
 
-def module(*args, **kwargs):
-    module_cmd = kwargs.get("module_template", "module " + " ".join(args))
+def module(
+    *args,
+    module_template: Optional[str] = None,
+    environb: Optional[MutableMapping[bytes, bytes]] = None,
+):
+    module_cmd = module_template or ("module " + " ".join(args))
+    environb = environb or os.environb
 
     if args[0] in module_change_commands:
         # Suppress module output
@@ -33,10 +39,10 @@ def module(*args, **kwargs):
             stderr=subprocess.STDOUT,
             shell=True,
             executable="/bin/bash",
+            env=environb,
         )
 
-        # In Python 3, keys and values of `environ` are byte strings.
-        environ = {}
+        new_environb = {}
         output = module_p.communicate()[0]
 
         # Loop over each environment variable key=value byte string
@@ -45,11 +51,11 @@ def module(*args, **kwargs):
             parts = entry.split(b"=", 1)
             if len(parts) != 2:
                 continue
-            environ[parts[0]] = parts[1]
+            new_environb[parts[0]] = parts[1]
 
         # Update os.environ with new dict
-        os.environ.clear()
-        os.environb.update(environ)  # novermin
+        environb.clear()
+        environb.update(new_environb)  # novermin
 
     else:
         # Simply execute commands that don't change state and return output