TeamCity对于JAVA的代码覆盖率我觉得弄得不好。
TeamCity开启EMMA测试会“智能”的对运行测试的Build Step加入部分步骤来完成代码覆盖的统计。其中有一个Coverage instrumentation parameters:可以设置，这个将是我们折腾的核心，一开始在使用它的默认值-ix -*Test*
注：如果开启EMMA后运行运行测试抛出java.lang.VerifyError异常可以参考，上一篇文章《java.lang.VerifyError运行时异常及处理方法》
我们来看一下TeamCity开启EMMA后会做些什么
在编译后TeamCity会自动帮我们加入EMMA: Instrumenting classes
具体行为类似
1: [08:29:22][compile] EMMA: Instrumenting classes 2: [08:29:22][EMMA: Instrumenting classes] EMMA commandline: [-ix, -*Test*, -cp, C:\TeamCity\buildAgent\work\7c011ec2a3494774\test\UnitTest\build, -m, overwrite] 3: [08:29:22][EMMA: Instrumenting classes] EMMA: processing instrumentation path ... 4: [08:29:22][EMMA: Instrumenting classes] EMMA: instrumentation path processed in 47 ms 5: [08:29:23][EMMA: Instrumenting classes] EMMA: [3 class(es) instrumented, 0 resource(s) copied] 6: [08:29:23][EMMA: Instrumenting classes] EMMA: metadata merged into [C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.em] {in 60 ms}核心当然是EMMA commandline部分
之后在运行代码后会加入EMMA: Create Report和三个Publishing artifacts过程。具体行为类似于
1: [08:29:24][Step 2/3] EMMA: Create Report 2: [08:29:24][EMMA: Create Report] EMMA commandline: [-r, html,txt, -in, C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.em,C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.ec, -Dreport.html.out.file=coverage/index.html, -Dreport.txt.out.file=C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.txt, -sp, C:\TeamCity\buildAgent\work\7c011ec2a3494774\test\UnitTest\src] 3: [08:29:24][EMMA: Create Report] EMMA: processing input files ... 4: [08:29:24][EMMA: Create Report] EMMA: 2 file(s) read and merged in 1 ms 5: [08:29:24][EMMA: Create Report] EMMA: writing [html] report to [C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage\index.html] ... 6: [08:29:24][EMMA: Create Report] EMMA: writing [txt] report to [C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.txt] ... 7: [08:29:24][Step 2/3] Process exited with code 0 8: [08:29:24][Step 2/3] Publishing artifacts (1s)9: [08:29:24][Publishing artifacts] Collecting files to publish: [C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.ec=>.teamcity/coverage_emma]
10: [08:29:26][Publishing artifacts] Sending coverage.ec 11: [08:29:24][Step 2/3] Publishing artifacts (1s)12: [08:29:24][Publishing artifacts] Collecting files to publish: [C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.em=>.teamcity/coverage_emma]
13: [08:29:26][Publishing artifacts] Sending coverage.em 14: [08:29:24][Step 2/3] Publishing artifacts (1s)15: [08:29:24][Publishing artifacts] Collecting files to publish: [C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage.txt=>.teamcity/coverage_emma]
16: [08:29:26][Publishing artifacts] Sending coverage.txt 17: [08:29:24][Step 2/3] Publishing artifacts (1s)18: [08:29:24][Publishing artifacts] Collecting files to publish: [C:\TeamCity\buildAgent\work\7c011ec2a3494774\coverage\coverage.zip=>.teamcity/coverage_emma]
19: [08:29:26][Publishing artifacts] Sending coverage/coverage.zip有了这些日志我们就可以根据自己的需要进行部分修改了。
比如说我将源代码的编译放在一个build step中，而测试代码的编译和运行放在另外一个build step中。这样在默认情况下就无法完成正确的Instrumenting classes
所以我将Coverage instrumentation parameters修改成-ix -*Test* -cp %teamcity.build.workingDir%\WebContent\WEB-INF\classes。
还有更极限的做法应该可以再ANT中直接完成EMMA的工作，而不要让TeamCity自作聪明的去处理