Added code to set can_clip to False on Linux if can't copy/paste clipboard

If Pyperclip could not find a copy/paste mechanism for your system, then
cmd2.can_clip gets set to False.

If cmd2.can_clip is False, then the "send_to_paste_buffer" test gets skipped.

2 files changed, 10 insertions, 8 deletions

diff --git a/cmd2.py b/cmd2.py
index cbb98ec7..97160515 100755
--- a/cmd2.py
+++ b/cmd2.py
@@ -303,8 +303,13 @@ def options(option_list, arg_desc="arg"):
     return option_setup
 
 
-# Can we access the clipboard?
+# Can we access the clipboard, always true on Windows and Mac, but only sometimes on Linux
 can_clip = True
+if sys.platform == 'linux':
+    try:
+        pyperclip.paste()
+    except pyperclip.exceptions.PyperclipException:
+        can_clip = False
 
 
 def get_paste_buffer():
diff --git a/tests/test_cmd2.py b/tests/test_cmd2.py
index db7f8cf7..d288f78f 100644
--- a/tests/test_cmd2.py
+++ b/tests/test_cmd2.py
@@ -472,23 +472,20 @@ def test_pipe_to_shell(base_app):
         assert out[0].strip() == expected[0].strip()
 
 
+@pytest.mark.skipif(not cmd2.can_clip,
+                    reason="Pyperclip could not find a copy/paste mechanism for your system")
 def test_send_to_paste_buffer(base_app):
     from cmd2 import can_clip
 
     # Test writing to the PasteBuffer/Clipboard
     run_cmd(base_app, 'help >')
     expected = normalize(BASE_HELP)
-
-    # If the tools for interacting with the clipboard/pastebuffer are available
-    if cmd2.can_clip:
-        # Read from the clipboard
-        assert normalize(cmd2.get_paste_buffer()) == expected
+    assert normalize(cmd2.get_paste_buffer()) == expected
 
     # Test appending to the PasteBuffer/Clipboard
     run_cmd(base_app, 'help history >>')
     expected = normalize(BASE_HELP + '\n' + HELP_HISTORY)
-    if cmd2.can_clip:
-        assert normalize(cmd2.get_paste_buffer()) == expected
+    assert normalize(cmd2.get_paste_buffer()) == expected
 
 
 def test_base_timing(base_app, capsys):