Improve coverage test

This patch adds a test tool borrowed from Rally project
to enable test coverage comparison between master and
proposed branch. With it, coverage test will fail if
new proposed change reduces the unit test coverage.

Change-Id: I0de9cf84eb82e1846aae57c35e33c8b789a629cc

.gitignore

@@ -2,6 +2,7 @@ AUTHORS
 ChangeLog
 build
 cover
+cover-master
 dist
 etc/senlin/senlin.conf.sample
 releasenodes/build

tools/cover.sh

@@ -0,0 +1,75 @@
+#!/bin/bash
+#
+#    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.
+
+# This tool is borrowed from Rally project and revised to enhance Senlin
+# coverage test.
+
+ALLOWED_EXTRA_MISSING=4
+
+show_diff () {
+    head -1 $1
+    diff -U 0 $1 $2 | sed 1,2d
+}
+
+if ! git diff --exit-code || ! git diff --cached --exit-code
+then
+    echo "There are uncommited changes!"
+    echo "Please clean git working directory and try again"
+    exit 1
+fi
+
+# Checkout master and save coverage report
+git checkout HEAD^
+
+baseline_report=$(mktemp -t senlin_coverageXXXXXXX)
+python setup.py test --coverage --testr-args="^(?!senlin\.tests\.tempest)"
+coverage report > $baseline_report
+cat $baseline_report
+mv cover cover-master
+baseline_missing=$(awk 'END { print $3 }' $baseline_report)
+
+# Checkout back and save coverage report
+git checkout -
+
+current_report=$(mktemp -t senlin_coverageXXXXXXX)
+python setup.py test --coverage --testr-args="^(?!senlin\.tests\.tempest)"
+coverage report > $current_report
+cat $current_report
+current_missing=$(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

@@ -73,7 +73,7 @@ commands = {posargs}
 
 [testenv:cover]
 setenv = VIRTUAL_ENV={envdir}
-commands = python setup.py test --coverage --testr-args="^(?!senlin\.tests\.tempest){posargs}"
+commands = {toxinidir}/tools/cover.sh {posargs}
 
 [testenv:docs]
 deps = -r{toxinidir}/test-requirements.txt