Imporve coverage job to make it voting

By default coverage job just generates cover directory with pretty HTML
report.

This change makes it voting:

It compares coverage of latest changes against that previous commit
and prints diff in case of adding new lines withou UT coverage.

As well it genereates HTML reports in cover/ dir

Change-Id: I1ac078ec67c92d0b8d6d3bb96f9ea79f61c5559a

.gitignore

@@ -35,6 +35,7 @@ pip-log.txt
 pip-delete-this-directory.txt
 
 # Unit test / coverage reports
+cover/
 htmlcov/
 .tox/
 .testrepository/

cue/tests/scripts/coverage.sh

@@ -0,0 +1,69 @@
+#!/bin/bash
+#
+# Copyright 2015: Mirantis Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+ALLOWED_EXTRA_MISSING=4
+
+show_diff () {
+    head -1 $1
+    diff -U 0 $1 $2 | sed 1,2d
+}
+
+# Stash uncommited changes, checkout master and save coverage report
+uncommited=$(git status --porcelain | grep -v "^??")
+[[ -n $uncommited ]] && git stash > /dev/null
+git checkout HEAD^
+
+baseline_report=$(mktemp -t rally_coverageXXXXXXX)
+python setup.py testr --coverage --testr-args="$*"
+coverage report > $baseline_report
+baseline_missing=$(awk 'END { print $3 }' $baseline_report)
+
+# Checkout back and unstash uncommited changes (if any)
+git checkout -
+[[ -n $uncommited ]] && git stash pop > /dev/null
+
+# Generate and save coverage report
+current_report=$(mktemp -t rally_coverageXXXXXXX)
+python setup.py testr --coverage --testr-args="$*"
+coverage report > $current_report
+current_missing=$(awk 'END { print $3 }' $current_report)
+
+# Show coverage details
+allowed_missing=$((baseline_missing+ALLOWED_EXTRA_MISSING))
+
+echo "Allowed to introduce missing lines : ${ALLOWED_EXTRA_MISSING}"
+echo "Missing lines in master            : ${baseline_missing}"
+echo "Missing lines in proposed change   : ${current_missing}"
+
+if [ $allowed_missing -gt $current_missing ];
+then
+    if [ $baseline_missing -lt $current_missing ];
+    then
+        show_diff $baseline_report $current_report
+        echo "I believe you can cover all your code with 100% coverage!"
+    else
+        echo "Thank you! You are awesome! Keep writing unit tests! :)"
+    fi
+    exit_code=0
+else
+    show_diff $baseline_report $current_report
+    echo "Please write more unit tests, we should keep our test coverage :( "
+    exit_code=1
+fi
+
+rm $baseline_report $current_report
+exit $exit_code

tox.ini

@@ -26,7 +26,7 @@ commands =
 [testenv:cover]
 setenv = VIRTUAL_ENV={envdir}
 commands =
-  python setup.py testr --coverage {posargs}
+  {toxinidir}/cue/tests/scripts/coverage.sh {posargs}
 
 [testenv:checkconfig]
 sitepackages = False