Updated tests.

.gitignore

@@ -15,3 +15,4 @@ htmlcov
 **/.DS_Store
 .eggs
 cppimport/_version.py
+*.lock

tests/conftest.py

@@ -0,0 +1,3 @@
+def pytest_addoption(parser):
+    parser.addoption('--multiprocessing', action='store_true', dest="multiprocessing",
+                 default=False, help="enable multiprocessing tests with filelock")

tests/test_cppimport.py

@@ -5,6 +5,7 @@
 import shutil
 import subprocess
 import sys
+import pytest
 from multiprocessing import Process
 from tempfile import TemporaryDirectory
 
@@ -13,6 +14,10 @@
 import cppimport.templating
 from cppimport.find import find_module_cpppath
 
+cppimport.settings["use_filelock"] = False  # No need for filelock except for
+                                            # multiprocessing test.
+multiprocessing_enable = pytest.mark.skipif("not config.getoption('multiprocessing')")
+
 root_logger = logging.getLogger()
 root_logger.setLevel(logging.DEBUG)
 
@@ -22,7 +27,6 @@
 handler.setFormatter(formatter)
 root_logger.addHandler(handler)
 
-
 @contextlib.contextmanager
 def appended(filename, text):
     with open(filename, "r") as f:
@@ -127,8 +131,11 @@ def test_with_file_in_syspath():
 def test_rebuild_after_failed_compile():
     cppimport.imp("mymodule")
     test_code = """
-import cppimport; mymodule = cppimport.imp("mymodule");assert(mymodule.add(1,2) == 3)
-"""
+import cppimport; 
+cppimport.settings["use_filelock"] = False; 
+mymodule = cppimport.imp("mymodule");
+assert(mymodule.add(1,2) == 3)
+    """
     with appended("tests/mymodule.cpp", ";asdf;"):
         subprocess_check(test_code, 1)
     subprocess_check(test_code, 0)
@@ -149,6 +156,7 @@ def test_no_rebuild_if_no_deps_change():
     cppimport.imp("mymodule")
     test_code = """
 import cppimport;
+cppimport.settings["use_filelock"] = False; 
 mymodule = cppimport.imp("mymodule");
 assert(not hasattr(mymodule, 'Thing'))
 """
@@ -160,6 +168,7 @@ def test_rebuild_header_after_change():
     cppimport.imp("mymodule")
     test_code = """
 import cppimport;
+cppimport.settings["use_filelock"] = False; 
 mymodule = cppimport.imp("mymodule");
 mymodule.Thing().cheer()
 """
@@ -214,8 +223,12 @@ def test_relative_import():
     print(f())
     assert f() == 3
 
-
+@multiprocessing_enable
 def test_multiple_processes():
+    '''
+    Only runs if the flag --multiprocessing is passed to
+    pytest. This function requires file locking enabled. 
+    '''
     with tmp_dir(["tests/hook_test.cpp"]) as tmp_path:
         test_code = f"""
 import os;