Update the string that clears the console.

[DanielBadan]

#1914
I've tested it with Windows 10 and 7, node versions from ~5.0.0 up to 7.7.0.
Didn't managed to test it on 8 but it should work to.

Before

After

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla - and if you have received this in error or have any questions, please drop us a line at [email protected]. Thanks!

If you are contributing on behalf of someone else (eg your employer): the individual CLA is not sufficient - use https://developers.facebook.com/opensource/cla?type=company instead. Contact [email protected] if you have any questions.

[gaearon]

I'm pretty sure \x1Bc was added intentionally on Windows. I don’t remember why though 😞

[DanielBadan]

It's probably not relevant any more. It worked for me without \x1Bc but I guess would be useful to have at least one more person to test that.

[Timer]

In the beginning we only used \x1bc, and then eventually switched to an alternative sequence for macOS because you could do fancier things.

Eventually we ended up copying Jest via jestjs/jest#2230.

Jest's latest sequence is https://github.com/facebook/jest/blob/master/packages/jest-cli/src/constants.js#L15, which appears identical to what we're still doing.

We can try \033c or \033[2J\033[0f (for windows).

[DanielBadan]

It seems to work with \033[2J\033[0f, only changed the numbers to Hex because of use strict so it's \x1B[2J\x1B[0f.

In windows 10 it clears the console with Git Bash, CMD and Powershell.
For 7 & 8 it clears the console with CMD and Powershell, no Git Bash.

[gaearon]

Am I correct that the current string fails in GitBash but works in other environments?
And that the proposed string fixes GitBash on Windows 10 but has no effect in other envs?

[DanielBadan]

Yes.
Windows 10: CMD, Powershell, Git Bash.
Windows 8: CMD, Powershell.
Windows 7: CMD, Powershell.

[gaearon]

I’ll test this later today.

[gaearon]

We’ll need a matching PR to Jest.

[gaearon]

This does seem to work better on a new Windows laptop I'm using. I don't understand why though. It even works in PowerShell but old sequence doesn't (with PowerShell too) on my new Windows laptop. How is this possible? Could some new Windows 10 versions break the old sequence?

[DanielBadan]

Probably just another weird thing of windows, the original sequence stopped working for me after an update.

[gaearon]

Can you send this PR to Jest too? https://github.com/facebook/jest

[gaearon]

Never mind, I sent jestjs/jest#5251.

[gaearon]

This is out in [email protected]! Please let us know if something doesn’t quite work.
https://github.com/facebookincubator/create-react-app/releases/tag/v1.1.0