Report descending sort option (#1005)

* added descending sort option in coverage report

* commandline option for report sort added

* Fix tests for pull #1005

* conditional statements improved

* sort option help updated with choices

* commandline test for sort added

Co-authored-by: Ned Batchelder <ned@nedbatchelder.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/coverage/summary.py b/coverage/summary.py
index 97d9fff0..986cd2f2 100644
--- a/coverage/summary.py
+++ b/coverage/summary.py
@@ -104,10 +104,18 @@ class SummaryReporter(object):
 
         # Sort the lines and write them out.
         if getattr(self.config, 'sort', None):
-            position = column_order.get(self.config.sort.lower())
+            sort_option = self.config.sort.lower()
+            reverse = False
+            if sort_option[0] == '-':
+                reverse = True
+                sort_option = sort_option[1:]
+            elif sort_option[0] == '+':
+                sort_option = sort_option[1:]
+
+            position = column_order.get(sort_option)
             if position is None:
                 raise CoverageException("Invalid sorting option: {!r}".format(self.config.sort))
-            lines.sort(key=lambda l: (l[1][position], l[0]))
+            lines.sort(key=lambda l: (l[1][position], l[0]), reverse=reverse)
 
         for line in lines:
             self.writeout(line[0])