v8.takeCoverage()方法允许用户按需将 NODE_V8_COVERAGE 开始的覆盖写入磁盘。 此方法可以在进程的生命周期内多次调用。 每次执行计数器将被重置,并且新的覆盖报告将写入 NODE_V8_COVERAGE 指定的目录。

The v8.takeCoverage() method allows the user to write the coverage started by NODE_V8_COVERAGE to disk on demand. This method can be invoked multiple times during the lifetime of the process. Each time the execution counter will be reset and a new coverage report will be written to the directory specified by NODE_V8_COVERAGE.

When the process is about to exit, one last coverage will still be written to disk unless v8.stopCoverage() is invoked before the process exits.