'test:start' 事件
data<Object>file<string> | <undefined> 测试文件的路径,如果测试未通过文件运行则未定义。name<string> 测试名称。nesting<number> 测试的嵌套级别。
测试开始时发出。
data<Object>file<string> | <undefined> The path of the test file, undefined if test is not ran through a file.name<string> The test name.nesting<number> The nesting level of the test.
Emitted when a test starts.