Add fine-grained control for deprecation warnings

[xanf]

Feature Description

Provide a way for fine-grained control of deprecation warnings, allowing each deprecation to be "silenced" one-by-one
Make config.showDeprecationWarnings to accept not only boolean, but also a fine-grained config, for example:

config.showDeprecationWarnings = [
  'find',
  'findAll',
  'isVisible',
  'options.attachToDocument',
  'options.methods'
];

Alternate approaches:

• new config silenceDeprecationWarnings with reverse behavior. The benefit of silenceDeprecationWarnings is that if new deprecation will be added - it will compain about it while showDeprecationWarnings will silently swallow it
• allowing to pass custom warnDeprecated function, so warnings could be handled in other way

Problem

When you have huge codebase it is a real pain to deal with all deprecations immediately. On the other side showDeprecationWarnings silences all warnings and will not complain if people are using deprecated function, which was already "cleaned" from the codebase

Expected behavior

VTU should show deprecation warnings for elements, specified in showDeprecationWarnings but keep silence for other deprecations

Alternatives

Right now I have such ugly code in setting my tests in Jest:

const originalConsoleError = global.console.error;
const ALLOWED_DEPRECATION_MESSAGES = [
  ...[
    // subject for automated codemod
    '`find`',
    '`findAll`',
    // requires custom matcher
    'isVisible',
    'setMethods',
    // 'is',
  ].map(method => `${method} is deprecated and will be removed in the next major version.`),
  'options.attachToDocument is deprecated in favor of options.attachTo', // +
  'overwriting methods via the `methods` property is deprecated',
  'name is deprecated and will be removed in the next major version', // easy
];

global.console.error = function consoleErrorWithSuppression(message, ...args) {
  if (
    message.startsWith('[vue-test-utils]') &&
    ALLOWED_DEPRECATION_MESSAGES.find(warning => message.includes(warning))
  ) {
    console.warn(message, ...args);
  }

  originalConsoleError.call(console, message, ...args);
};

I'm quite uncomfortable with this hack and will be happy to submit PR as soon as the desired direction will be selected

[lmiller1990]

I don't think the hack is that bad - essentially this request is just to move that logic into VTU. I don't see a significant downside to adding this to VTU - it's purely additive. I wonder if many other people are having the problem (GL has likely one of the largest Vue code-bases on the planet, haha).

I don't have a strong opinion, either way. How about we get a fix for #1532 merged up then tackle this? I think #1532 has higher immediate value, and probably reduce your deprecation warnings a lot as well.

[xanf]

@lmiller1990 sure thing, I'll start my work on #1532 immediately, thanks for swift response