test_help: test "help" command without cache

This test case addresses upsteam ticket #6999, where "ipa help"
does not work if called when no schema is cached.

https://pagure.io/freeipa/issue/7325

Reviewed-By: Christian Heimes <cheimes@redhat.com>

ipatests/test_cmdline/test_help.py

@@ -18,6 +18,9 @@
 #
 
 import sys
+import os
+import shutil
+import errno
 
 import six
 from six import StringIO
@@ -73,6 +76,27 @@ def test_ipa_help():
     assert ctx.stderr == ''
 
 
+def test_ipa_help_without_cache():
+    """Test `ipa help` without schema cache"""
+    cache_dir = os.path.expanduser('~/.cache/ipa/schema/')
+    backup_dir = os.path.expanduser('~/.cache/ipa/schema.bak/')
+    shutil.rmtree(backup_dir, ignore_errors=True)
+    if os.path.isdir(cache_dir):
+        os.rename(cache_dir, backup_dir)
+    try:
+        with CLITestContext() as ctx:
+            return_value = api.Backend.cli.run(['help'])
+        assert return_value == 0
+        assert ctx.stderr == ''
+    finally:
+        shutil.rmtree(cache_dir, ignore_errors=True)
+        try:
+            os.rename(backup_dir, cache_dir)
+        except OSError as e:
+            if e.errno != errno.ENOENT:
+                raise
+
+
 def test_ipa_without_arguments():
     """Test that `ipa` errors out, and prints the help to stderr"""
     with CLITestContext(exception=SystemExit) as ctx:
@@ -137,6 +161,7 @@ def test_ambiguous_command_or_topic():
 
     assert h_ctx.stdout != help_ctx.stdout
 
+
 def test_multiline_description():
     """Test that all of a multi-line command description appears in output
     """