Code coverage helpers.

Makefile

@@ -15,8 +15,11 @@ clean:
 unit_test:
 	go test ./go/...
 
+# Run the code coverage tools, compute aggregate.
+# If you want to improve in a directory, run:
+#   go test -coverprofile=coverage.out && go tool cover -html=coverage.out
 unit_test_cover:
-	go test -cover ./go/...
+	go test -cover ./go/... | misc/parse_cover.py
 
 unit_test_race:
 	go test -race ./go/...

misc/parse_cover.py

@@ -0,0 +1,31 @@
+#!/usr/bin/python
+
+# this is a small helper script to parse test coverage and display stats.
+import re
+import sys
+
+coverage_pattern = re.compile(r"coverage: (\d+).(\d+)% of statements")
+
+no_test_file_count = 0
+coverage_count = 0
+coverage_sum = 0.0
+
+for line in sys.stdin:
+  print line,
+  sys.stdout.flush
+
+  if line.find('[no test files]') != -1:
+    no_test_file_count += 1
+    continue
+
+  m = coverage_pattern.search(line)
+  if m != None:
+    coverage_count += 1
+    coverage_sum += float(m.group(1) + "." + m.group(2))
+    continue
+
+directories_covered = coverage_count * 100 / (no_test_file_count + coverage_count)
+average_coverage = coverage_sum / coverage_count
+
+print "Directory test coverage: %u%%" % directories_covered
+print "Average test coverage: %u%%" % int(average_coverage)