Berry: [Bug] `preferInteractive` has no effect

[ikatyang]

Describe the bug

According to the docs, preferInteractive: true should imply --interactive flag on every yarn add, but adding preferInteractive to yarnrc.yml has no effect.

To Reproduce

Reproduction

```js repro
await packageJson({ name: 'root', workspaces: ['packages/*'] })
await packageJson({ name: 'package-a', dependencies: { typescript: '3.8' } }, 'packages/package-a')

await expect(yarn('add', 'typescript', '--interactive', { timeout: 60000 })).rejects.toThrow(Command failed) // failed as expected because of interactive mode
require('fs').writeFileSync('.yarnrc.yml', 'preferInteractive: true')
await expect(yarn('add', 'typescript', { timeout: 60000 })).rejects.toThrow(Command failed) // it should also fail because of interactive mode, but succeeded as if there is no preferInteractive
```

Environment

• Yarn version 2.0.0-rc.36

Additional context

I cannot find any preferInteractive text in this repo other than docs.

[yarnbot]

We couldn't reproduce your issue (all the assertions passed on master).

[yarnbot]

We couldn't reproduce your issue (all the assertions passed on master).

[yarnbot]

This issue reproduces on master:

Error: expect(received).rejects.toThrow()

Received promise resolved instead of rejected
Resolved to value: "➤ YN0000: ┌ Resolution step
::group::Resolution step
::endgroup::
➤ YN0000: └ Completed in 0.44s
➤ YN0000: ┌ Fetch step
::group::Fetch step
➤ YN0013: │ No packages were cached - 3 packages had to be fetched
::endgroup::
➤ YN0000: └ Completed in 42.94s
➤ YN0000: ┌ Link step
::group::Link step
::endgroup::
➤ YN0000: └ Completed
➤ YN0000: Done in 43.43s
"
    at expect (/github/workspace/.yarn/cache/expect-npm-24.8.0-8c7640c562-0ac41999f0.zip/node_modules/expect/build/index.js:138:15)
    at module.exports (evalmachine.<anonymous>:7:7)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async /github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/executeRepro.js:56:13
    at async executeInTempDirectory (/github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/executeRepro.js:17:16)
    at async Object.executeRepro (/github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/executeRepro.js:24:12)
    at async ExecCommand.execute (/github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/commands/exec.js:25:38)
    at async ExecCommand.validateAndExecute (/github/workspace/.yarn/cache/clipanion-npm-2.0.0-rc.16-b9444aaf89-a57989414f.zip/node_modules/clipanion/lib/advanced/Command.js:161:26)
    at async Cli.run (/github/workspace/.yarn/cache/clipanion-npm-2.0.0-rc.16-b9444aaf89-a57989414f.zip/node_modules/clipanion/lib/advanced/Cli.js:74:24)
    at async Cli.runExit (/github/workspace/.yarn/cache/clipanion-npm-2.0.0-rc.16-b9444aaf89-a57989414f.zip/node_modules/clipanion/lib/advanced/Cli.js:83:28)

[yarnbot]

This issue reproduces on master:

Error: expect(received).rejects.toThrow()

Received promise resolved instead of rejected
Resolved to value: "➤ YN0000: ┌ Resolution step
::group::Resolution step
::endgroup::
➤ YN0000: └ Completed in 0.42s
➤ YN0000: ┌ Fetch step
::group::Fetch step
➤ YN0013: │ No packages were cached - 3 packages had to be fetched
::endgroup::
➤ YN0000: └ Completed in 41.26s
➤ YN0000: ┌ Link step
::group::Link step
::endgroup::
➤ YN0000: └ Completed
➤ YN0000: Done in 41.74s
"
    at expect (/github/workspace/.yarn/cache/expect-npm-24.8.0-8c7640c562-0ac41999f0.zip/node_modules/expect/build/index.js:138:15)
    at module.exports (evalmachine.<anonymous>:7:7)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async /github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/executeRepro.js:56:13
    at async executeInTempDirectory (/github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/executeRepro.js:17:16)
    at async Object.executeRepro (/github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/executeRepro.js:24:12)
    at async ExecCommand.execute (/github/workspace/.yarn/cache/@arcanis-sherlock-npm-1.0.38-d4f5e2dbf3-63f998598d.zip/node_modules/@arcanis/sherlock/lib/commands/exec.js:25:38)
    at async ExecCommand.validateAndExecute (/github/workspace/.yarn/cache/clipanion-npm-2.0.0-rc.16-b9444aaf89-a57989414f.zip/node_modules/clipanion/lib/advanced/Command.js:161:26)
    at async Cli.run (/github/workspace/.yarn/cache/clipanion-npm-2.0.0-rc.16-b9444aaf89-a57989414f.zip/node_modules/clipanion/lib/advanced/Cli.js:74:24)
    at async Cli.runExit (/github/workspace/.yarn/cache/clipanion-npm-2.0.0-rc.16-b9444aaf89-a57989414f.zip/node_modules/clipanion/lib/advanced/Cli.js:83:28)

[paul-soporan]

🤔 Looks like yet another one of those "not yet implemented, but somehow documented" features that somehow somebody took the time document. 😅
I'm going to implement it soon 👍