Support should not send coverage unless plugins task has been registered

in a situation where a support file has been registered BUT there is no task in the plugins file, we should not try to call the coverage report task

Example situation

{
  "pluginsFile": false,
  "supportFile": "node_modules/cypress-react-unit-test/support"
}

[gwvt]

How do you keep the coverage tasks registered when using multiple config files as documented at https://docs.cypress.io/api/plugins/configuration-api#Customize-available-browsers?

In plugins/index.js as documented there:

module.exports = (on, config) => {
  const environment = config.env.configFile || "development";
  const configurationForEnvironment = fetchConfigurationByFile(environment);

  return configurationForEnvironment || config;
};

How do you incorporate

  require('@cypress/code-coverage/task')(on, config);

to register the coverage tasks on the returned config object? Config by file works but without coverage. Coverage works without config by file (i.e., just returning config). I can’t get both to work together…

[CharlesStover]

Is it possible for this to throw an error? I’ve been debugging for days why I’m not getting any coverage files in my CI workflow. Local tests didn’t give me anything either, and this warning was simply not visible: It was sheer happenstance that I ran a one-liner test on a local Cypress instance and saw this banner.

The end problem was that my plugins file’s default export wasn’t returning config after I mutated it with @cypress/code-coverage:

import task from '@cypress/code-coverage';
export default function(on, config) {
  task(on, config);
  return config; // <-- REQUIRED
}

This would have been so much easier to debug if CI had failed with an error that the code coverage task had not registered instead of failing silently.