npm + Mocha——观察(不准确地观察文件)

I'm using Mocha with npm, and doing an "npm test" to start up mocha. It has the --watch enabled in the mocha.opts, but for some reason it's not accurately watching. When I make a change to my test file, and then save it, whether I put in a faulty test or an ok test, I get the same thing: 0 passing (in green), whereas, when I first run mocha, I get 2 passing.I'm using Mocha with npm, and doing an "npm tes