fix: UI validation for existing email during user registration

[Anxhul10]

Proposed changes (including videos or screenshots)

• Added front-end validation to display an error message when a user attempts to register with an email that's already in use.
• Updated the backend to return a specific error code for duplicate email registration attempts.

Screencast.from.2025-02-20.22-40-53.webm

Issue(s)

Closes #35263
CORE-1011

Steps to test or reproduce

Further comments

---

This pull request addresses an issue in the Rocket.Chat user registration process by implementing a fix for email validation to prevent duplicate email registrations. The changes include:

1. UI Validation: A changeset has been introduced to enhance the registration form's email validation, ensuring that users cannot register with an email that is already in use.

2. API Enhancement: The user registration API endpoint (users.register) has been updated to include an email availability check. The checkEmailAvailability function is now used to verify if the provided email already exists in the system. If the email is found to be already registered, an error is returned, preventing the creation of a new user with the same email.

These changes are made in the source branch fix/email-already-registered and are intended to be merged into the develop branch.

[dionisio-bot]

Looks like this PR is not ready to merge, because of the following issues:

• This PR is targeting the wrong base branch. It should target 7.9.0, but it targets 7.8.0

Please fix the issues and try again

If you have any trouble, please check the PR guidelines

[changeset-bot]

🦋 Changeset detected

Latest commit: dc912dd

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 37 packages

Name	Type
@rocket.chat/meteor	Patch
@rocket.chat/web-ui-registration	Patch
@rocket.chat/core-typings	Patch
@rocket.chat/rest-typings	Patch
@rocket.chat/uikit-playground	Patch
@rocket.chat/api-client	Patch
@rocket.chat/apps	Patch
@rocket.chat/core-services	Patch
@rocket.chat/cron	Patch
@rocket.chat/ddp-client	Patch
@rocket.chat/freeswitch	Patch
@rocket.chat/fuselage-ui-kit	Patch
@rocket.chat/gazzodown	Patch
@rocket.chat/http-router	Patch
@rocket.chat/livechat	Patch
@rocket.chat/model-typings	Patch
@rocket.chat/ui-contexts	Patch
@rocket.chat/account-service	Patch
@rocket.chat/authorization-service	Patch
@rocket.chat/ddp-streamer	Patch
@rocket.chat/omnichannel-transcript	Patch
@rocket.chat/presence-service	Patch
@rocket.chat/queue-worker	Patch
@rocket.chat/stream-hub-service	Patch
@rocket.chat/license	Patch
@rocket.chat/omnichannel-services	Patch
@rocket.chat/pdf-worker	Patch
@rocket.chat/presence	Patch
rocketchat-services	Patch
@rocket.chat/models	Patch
@rocket.chat/network-broker	Patch
@rocket.chat/mock-providers	Patch
@rocket.chat/ui-avatar	Patch
@rocket.chat/ui-client	Patch
@rocket.chat/ui-video-conf	Patch
@rocket.chat/ui-voip	Patch
@rocket.chat/instance-status	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[Anxhul10]

I just realized that 'tasked' issues are already assigned.
As tasked issues have been referred to the devs for them to fix. Should I close this PR, or would it still be helpful in any way? I'll make sure to pick unassigned issues next time.

[MartinSchoeler]

I just realized that 'tasked' issues are already assigned. As tasked issues have been referred to the devs for them to fix. Should I close this PR, or would it still be helpful in any way? I'll make sure to pick unassigned issues next time.

I don't think anyone is working on that at the moment, so it should be fine

Can you fix the lint errors?

Thanks!

[Anxhul10]

I just realized that 'tasked' issues are already assigned. As tasked issues have been referred to the devs for them to fix. Should I close this PR, or would it still be helpful in any way? I'll make sure to pick unassigned issues next time.

I don't think anyone is working on that at the moment, so it should be fine

Can you fix the lint errors?

Thanks!

I have fixed the lint errors .
but it fails at CI / deploy-preview (pull_request) Failing after 3m

[Anxhul10]

Hi
I'm working on a PR and noticed that both yarn lint and yarn testunit fail—not just on my PR but also on a fresh clone of the latest develop branch. However, yarn build:ci passes in both cases.

yarn lint on fresh clone

yarn testunit on fresh repo

yarn build:ci on my current pr

yarn storybook on my pr as well as fresh repo ( left is my pr and right side is fresh repo )

I donot know what is causing the the workflow to fail . Can you please guide me how to fix it .