CLI: Improve support of Yarn 2 in E2E tests

[gaetanmaisse]

Work summary

Currently, there is only one E2E test that uses Yarn 2, it's a simple CRA setup: https://github.com/storybookjs/storybook/pull/10702/files#diff-054afb61fcbf5f01b1e17e1341d869e4R147-R154

It would be great if the package manager used when running E2E tests was a CLI param and everything needed to bootstrap and run tests were using NPM or Yarn accordingly to that param.

By doing so:

• We will be able to have all E2E on Npm or Yarn 2 without duplicating the configs
• Increasing the test coverage, we will become way more confidant about Yarn 2 support and non-regression

This work is part of #10723

Where to start

📚 Surely, read some doc about Yarn 2.

🏗️ Then try to extract all references to npx or npm install to functions or class that will hide the specific syntax of each package manager (i.e. use yarn dlx for Yarn instead of npx etc).

⚔️ Fight with something because it will not be so simple.

🎛️ Update the Yarn 2 E2E tests job in Circle CI config file to run E2E tests with Yarn 2 for as much framework as possible (some are incompatible with Yarn 2 for now).

Acceptance criteria

• Current E2E tests are passing
• New Yarn 2 E2E tests are passing
• Changes are properly reviewed by some of the members mentioned below

Who to contact

@gaetanmaisse @ndelangen @tooppaaa @yannbf

[gaetanmaisse]

Don't worry @Stale we will do it ;)

[shilman]

Zoinks!! I just released https://github.com/storybookjs/storybook/releases/tag/v6.0.0-rc.16 containing PR #11354 that references this issue. Upgrade today to try it out!

You can find this prerelease on the @next NPM tag.

Closing this issue. Please re-open if you think there's still more to do.