Fix unit tests on macOS when gnureadline is installed

As similar try/except needed to be added to a couple unit test files to try to import gnureadline as readline and fallback to importing readline.

Author: tleonhardt

tests/test_argparse.py

@@ -5,7 +5,6 @@
 import argparse
 import functools
 import pytest
-import readline
 import sys
 
 import cmd2
@@ -14,6 +13,18 @@
 
 from conftest import run_cmd, StdOut
 
+# Prefer statically linked gnureadline if available (for macOS compatibility due to issues with libedit)
+try:
+    import gnureadline as readline
+except ImportError:
+    # Try to import readline, but allow failure for convenience in Windows unit testing
+    # Note: If this actually fails, you should install readline on Linux or Mac or pyreadline on Windows
+    try:
+        # noinspection PyUnresolvedReferences
+        import readline
+    except ImportError:
+        pass
+
 
 class ArgparseApp(cmd2.Cmd):
     def __init__(self):

tests/test_completion.py

@@ -10,7 +10,6 @@
 """
 import argparse
 import os
-import readline
 import sys
 
 import cmd2
@@ -19,6 +18,19 @@
 
 from cmd2 import path_complete, basic_complete, flag_based_complete, index_based_complete
 
+# Prefer statically linked gnureadline if available (for macOS compatibility due to issues with libedit)
+try:
+    import gnureadline as readline
+except ImportError:
+    # Try to import readline, but allow failure for convenience in Windows unit testing
+    # Note: If this actually fails, you should install readline on Linux or Mac or pyreadline on Windows
+    try:
+        # noinspection PyUnresolvedReferences
+        import readline
+    except ImportError:
+        pass
+
+
 @pytest.fixture
 def cmd2_app():
     c = cmd2.Cmd()