FIX: Make `email` a required param when accepting invite links.

A missing email when accepting an invite link does not make sense so we
should make it a required param which helps to catch bugs in our test
suite and also prevent potential bugs in our code base when the code
trips on a `nil` email.

app/controllers/invites_controller.rb

@@ -145,14 +145,23 @@ class InvitesController < ApplicationController
 
     if invite.present?
       begin
-        user = invite.redeem(
-          email: invite.is_invite_link? ? params[:email] : invite.email,
+        attrs = {
           username: params[:username],
           name: params[:name],
           password: params[:password],
           user_custom_fields: params[:user_custom_fields],
           ip_address: request.remote_ip
-        )
+        }
+
+        attrs[:email] =
+          if invite.is_invite_link?
+            params.require([:email])
+            params[:email]
+          else
+            invite.email
+          end
+
+        user = invite.redeem(attrs)
       rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotSaved => e
         return render json: failed_json.merge(errors: e.record&.errors&.to_hash, message: I18n.t('invite.error_message')), status: 412
       rescue Invite::UserExists => e

spec/requests/invites_controller_spec.rb

@@ -337,7 +337,7 @@ describe InvitesController do
       fab!(:invite_link) { Fabricate(:invite, email: nil, max_redemptions_allowed: 5, expires_at: 1.day.ago, emailed_status: Invite.emailed_status_types[:not_required]) }
 
       it "response is not successful" do
-        put "/invites/show/#{invite_link.invite_key}.json"
+        put "/invites/show/#{invite_link.invite_key}.json", params: { email: "foobar@example.com" }
 
         expect(response.status).to eq(404)
         expect(response.parsed_body["message"]).to eq(I18n.t('invite.not_found_json'))