[CAL-3055] 500 when inviting a team member and there's a conflict in the generated username

[zomars]

The bug comes from here:

cal.com/packages/trpc/server/routers/viewer/teams/inviteMember/utils.ts

Lines 235 to 258 in d6927c5

	const usernameOrEmail = usernamesOrEmails[index];
	const { orgId, autoAccept } = connectionInfoMap[usernameOrEmail];
	const [emailUser, emailDomain] = usernameOrEmail.split("@");
	const username =
	emailDomain === autoAcceptEmailDomain
	? slugify(emailUser)
	: slugify(`${emailUser}-${emailDomain.split(".")[0]}`);
	const createdUser = await tx.user.create({
	data: {
	username,
	email: usernameOrEmail,
	verified: true,
	invitedTo: input.teamId,
	organizationId: orgId || null, // If the user is invited to a child team, they are automatically added to the parent org
	teams: {
	create: {
	teamId: input.teamId,
	role: input.role as MembershipRole,
	accepted: autoAccept, // If the user is invited to a child team, they are automatically accepted
	},
	},
	},
	});

This is causing a weird edge case where there might be the possibility that the generated user may exist already. causing a prisma error. Example: we have robert@example.com being converted to robert-example username. Which already exists in prod. On production this only returns a 500 error:

On dev we get this:

Object { message: "Invalid `prisma.user.create()` invocation: Unique constraint failed on the fields: (`username,`)", code: -32603, data: {…} }

Originally posted by @zomars in #11238 (comment)

_{From SyncLinear.com | CAL-3055}