Consolidated coverage report generation into one rake command.

Added diff coverage reports using diff-coverage tool.

doc/testing.md

@@ -197,9 +197,10 @@ To view test coverage:
 
 2. Generate reports:
 
-        rake coverage:html
+        rake coverage
 
-3. HTML reports are located in the `reports` folder.
+3. Reports are located in the `reports` folder.  The command
+generates HTML and XML (Cobertura format) reports.
 
 
 ## Testing using queue servers

jenkins/test.sh

@@ -84,7 +84,8 @@ rake phantomjs_jasmine_cms || TESTS_FAILED=1
 rake phantomjs_jasmine_common/lib/xmodule || TESTS_FAILED=1
 rake phantomjs_jasmine_common/static/coffee || TESTS_FAILED=1
 
-rake coverage:xml coverage:html
+# Generate coverage reports
+rake coverage
 
 [ $TESTS_FAILED == '0' ]
 rake autodeploy_properties

rakefiles/tests.rake

@@ -119,30 +119,17 @@ task :test do
     end
 end
 
-namespace :coverage do
-    desc "Build the html coverage reports"
-    task :html => :report_dirs do
-        TEST_TASK_DIRS.each do |dir|
-            report_dir = report_dir_path(dir)
+desc "Build the html, xml, and diff coverage reports"
+task :coverage => :report_dirs do
+    TEST_TASK_DIRS.each do |dir|
+        report_dir = report_dir_path(dir)
 
-            if !File.file?("#{report_dir}/.coverage")
-                next
-            end
-
-            sh("coverage html --rcfile=#{dir}/.coveragerc")
+        if !File.file?("#{report_dir}/.coverage")
+            next
         end
-    end
 
-    desc "Build the xml coverage reports"
-    task :xml => :report_dirs do
-        TEST_TASK_DIRS.each do |dir|
-            report_dir = report_dir_path(dir)
-
-            if !File.file?("#{report_dir}/.coverage")
-                next
-            end
-            # Why doesn't the rcfile control the xml output file properly??
-            sh("coverage xml -o #{report_dir}/coverage.xml --rcfile=#{dir}/.coveragerc")
-        end
+        sh("coverage html --rcfile=#{dir}/.coveragerc")
+        sh("coverage xml -o #{report_dir}/coverage.xml --rcfile=#{dir}/.coveragerc")
+        sh("diff-cover #{report_dir}/coverage.xml --html-report #{report_dir}/diff_cover.html --git-branch master...HEAD")
     end
 end