#17668 disabled support for "copy to clipboard" and "go to definition" context menu items in Firefox. 

Use cases

- [x] copy to clipboard (#17740)
- [x] jump to element node (blocked by Firefox bugs [1605597](https://bugzilla.mozilla.org/show_bug.cgi?id=1605597), [1609671](https://bugzilla.mozilla.org/show_bug.cgi?id=1609671), [1609677](https://bugzilla.mozilla.org/show_bug.cgi?id=1609677))
- [x] jump to function definition (blocked by Firefox bugs [1605597](https://bugzilla.mozilla.org/show_bug.cgi?id=1605597), [1609671](https://bugzilla.mozilla.org/show_bug.cgi?id=1609671), [1609677](https://bugzilla.mozilla.org/show_bug.cgi?id=1609677))
const chalk = require('chalk');
const build = require('../build');
const main = async () => {
  await build('firefox');
  console.log(chalk.green('\nThe Firefox extension has been built!'));
  console.log(chalk.green('You can test this build by running:'));
  console.log(chalk.gray('\n# From the react-devtools root directory:'));
  console.log('yarn run test:firefox');
  console.log(
    chalk.gray('\n# You can also test against upcoming Firefox releases.')
  );
  console.log(
    chalk.gray(
      '# First download a release from https://www.mozilla.org/en-US/firefox/channel/desktop/'
    )
  );
  console.log(
    chalk.gray(
      '# And then tell web-ext which release to use (eg firefoxdeveloperedition, nightly, beta):'
    )
  );
  console.log('WEB_EXT_FIREFOX=nightly yarn run test:firefox');
  console.log(chalk.gray('\n# You can test against older versions too:'));
  console.log(
    'WEB_EXT_FIREFOX=/Applications/Firefox52.app/Contents/MacOS/firefox-bin yarn run test:firefox'
  );
};
main();
module.exports = {main};