see if this is the answer you want. https://cloud.tencent.com/dev.

found the problem, because I thought that the istanbul plug-in effect of webpack loader and babel was different, so the istanbul plug-in was set in webpack loader and babel at the same time, so the exclude configured in istanbul-instrumenter-loader did not take effect. Because babel has counted it once before him, and if one of them is removed, it will be ok. However, the statistics of webpack's loader and babel plug-ins seem to be different, so let's compare the gap later.

if you use @ vue/cli3, it already has one for you, just connect to babel-plugin-istanbul . ides/-sharp%E7%94%A8-karma-%E6%B5%8B%E8%AF%95%E5%8D%95%E6%96%87%E4%BB%B6%E7%BB%84%E4%BB%B6" rel=" nofollow noreferrer "> refer to the whole operation on the official website

this is actually configured by babel in cross-env. back to your question, if you are based on a configuration above @ vue/cli3, you only need to modify the configuration of the babelrc or babel.config.js file:

usually looks like this:

  'env': {
    'test': {
      'plugins': ['istanbul']
    }
  }

replace it with:

  'env': {
    'test': {
      'plugins': [
        [
          'istanbul',
          { 'exclude': [ 'tests/**' ] }
        ]
      ]
    }
  }

is actually matching the exclude option.

PS:

the advantage of this change is that it actually modifies the configuration of npm run script's cross-env, rather than modifying webpack to change the configuration of the entire project.