Improve coverage

tests/test_cmdline.py

@@ -591,6 +591,13 @@ class TestCmdline(object):
                   exitcode = 2, require_error = False)
         self.contain("no data")
 
+        # unannotated empty extract is just empty, with an exit code of 2
+        self.fail("extract /newton/prep " +
+                  "--start '23 Mar 2022 10:00:30' " +
+                  "--end '23 Mar 2022 10:00:31'",
+                  exitcode = 2, require_error = False)
+        self.match("")
+
         # but are ok if we're just counting results
         self.ok("extract --count /newton/prep " +
                 "--start '23 Mar 2012 20:00:30' " +
@@ -601,6 +608,14 @@ class TestCmdline(object):
                 "--end '23 Mar 2012 20:00:30.000002'")
         self.match("0\n")
 
+        # Extract needs --start and --end
+        self.fail("extract -a /newton/prep")
+        self.contain("arguments are required")
+        self.fail("extract -a /newton/prep --start 2000-01-01")
+        self.contain("arguments are required")
+        self.fail("extract -a /newton/prep --end 2000-01-01")
+        self.contain("arguments are required")
+
         # Check various dumps against stored copies of how they should appear
         def test(file, start, end, extra=""):
             self.ok("extract " + extra + " /newton/prep " +