1 files changed, 47 insertions, 0 deletions
diff --git a/tests/conftest.py b/tests/conftest.py
index 837e7504..ed76cba9 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -8,9 +8,21 @@ Released under MIT license, see LICENSE file
 import sys
 
 from pytest import fixture
+from unittest import mock
 
 import cmd2
 
+# 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
 
 # Help text for base cmd2.Cmd application
 BASE_HELP = """Documented commands (type help <topic>):
@@ -141,3 +153,38 @@ def base_app():
     c = cmd2.Cmd()
     c.stdout = StdOut()
     return c
+
+
+def complete_tester(text, line, begidx, endidx, app):
+    """
+    This is a convenience function to test cmd2.complete() since
+    in a unit test environment there is no actual console readline
+    is monitoring. Therefore we use mock to provide readline data
+    to complete().
+
+    :param text: str - the string prefix we are attempting to match
+    :param line: str - the current input line with leading whitespace removed
+    :param begidx: int - the beginning index of the prefix text
+    :param endidx: int - the ending index of the prefix text
+    :param app: the cmd2 app that will run completions
+    :return: The first matched string or None if there are no matches
+             Matches are stored in app.completion_matches
+             These matches also have been sorted by complete()
+    """
+    def get_line():
+        return line
+
+    def get_begidx():
+        return begidx
+
+    def get_endidx():
+        return endidx
+
+    first_match = None
+    with mock.patch.object(readline, 'get_line_buffer', get_line):
+        with mock.patch.object(readline, 'get_begidx', get_begidx):
+            with mock.patch.object(readline, 'get_endidx', get_endidx):
+                # Run the readline tab-completion function with readline mocks in place
+                first_match = app.complete(text, 0)
+
+    return first_match